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User Manual - Stanford Research Systems

1. Plot Error 1 Print Error 2 Memory Error 3 Disk Error 4 Unused 5 Unlock 6 Rate Error 7 Overflow usage Set when an error occurs during plotting Set when an error occurs during a print screen operation Set when a memory error is detected Set when an error occurs during a disk or file operation Set when the internal bin clock time base is not valid Set when a trigger arrives while the previous record is still being acquired or accumulated Set when the count in any bin overflows during acquisition or accumulation The Error Status bits stay set until cleared by reading or by the CLS command 94 Remote Programming FILE FORMATS The formats of the files stored by the SR430 are described below Disks written by the SR430 may be read on a MSDOS computer with a 3 5 disk drive However the files are not stored as ASCII files They cannot be simply typed on the screen The data is stored in binary format to keep the length of the files as short as possible In the following table byte 0 refers to the first byte in the file Integer and real number formats follow the Microsoft formats TRACE FILE Byte Type Explanation 0 11 ASCII character The string SR430_TRACE lt cr gt appears at the begin ning of the file 12 2 byte integer bin width 0 19 see BWTH command 14 15 reserved 16 2 byte integer bins per record 1 16 see BREC command 18 35 reserved 36 4 byte real minimum data value i
2. Baseline Tot 3 840000 004 to Continue The Left and Right Limit functions set the left and right limits of the calcu lation region The default positions of the limits are the the left and right edges of the graph To move a limit move the cursor using the knob or PEAK key to the desired location of the limit Pressing the Left or Right Limit key will set the limit to the cursor position The Limits are set each time a limit key is pressed The limits are shown as heavy dashed verti cal lines on the graph See the description of Limits under the Fit sub menu The Return key will return to the main Math menu 66 PLOT MENU Introduction The Plot menu is used to plot the screen display to an HPGL compatible plotter Use the Setup Plotter menu to configure the plotter interface plot speed and pen definition All Plot Trace Plot Trace Plot Cursor Plot Cursor Plot All The Plot All key generates a plot of the entire screen Each feature uses the pen assigned in the Setup Plotter menu Features such as the cursor or a curve fit are plotted only if they are presently displayed Plot Trace The Plot Trace key plots only the data trace This allows multiple data traces to be plotted on a single sheet Traces may be made in different colors by changing pen definitions or pens between plots Plot Cursor The Plot Cursor key plots the cursor markers if the cursor is presently displayed on the
3. 250 ns 150 us or 450 ys and the trigger peri od is 1 ms When data acquisition is complete the Status indi cator should display DONE Use the AUTO SCALE key to scale the display In each record each 40 ns bin will count 2 pulses the TEST pulse period is 20 ns and 1000 records will accumulate 2000 counts in each bin The first bin is an excep tion The first bin always counts one less than the rest of the bins and so will have 1000 counts in it Use the display and cursor to verify that the data is correct If there is some variation from bin to bin that may be because the cable connecting the TEST output to the SIGNAL input delays the test pulses such that they always occur right on a bin boundary In that case even though no counts are lost there will be some variation as to which bin each pulse goes into Use a slightly longer cable or add a short length of cable to delay the pulses away from the bin boundaries In either case the total number of counts should be correct Clear the data using the STOP key Select a bin width of 5 ns Press the START key to accumu late 1000 records again In this case only every Test and Calibration 4th bin will have counts in it This is because the TEST pulses come every 20 ns When the data acquisition is DONE every 4th bin should have 1000 counts in it Once again if the pulses are landing on the bin boundaries add a short length of cable to delay the pulses Also addin
4. AXIAL Capacitor Ceramic 50V 80 20 250 AX C 64 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 139 art 15 EEEEEREILLLLIGIUILIIUGULUIIIULLILUILIUIILLIIG LIP I UICCBGSuH LUOALLULI CGUGQGGGGHUuuNLLOAALLLULLL GGI J C 65 C 801 C 901 C 902 C 903 C 904 C 1301 C 1601 C 1602 C 1603 C 1604 C 1605 JP801 JP1200 JP1201 JP1601 JP1602 JP1603 N 801 N 802 N 1001 N 1002 N 1003 N 1004 P 1601 PC1 Q 1001 Q 1002 R 801 R 901 R 902 R 903 R 904 R 1001 R 1002 R 1301 R 1302 R 1303 R 1304 R 1305 R 1306 R 1307 R 1308 R 1309 R 1601 R 1602 R 1603 R 1604 R 1605 R 1606 R 1607 R 1608 R 1609 R 1610 R 1611 5 00225 548 5 00052 512 5 00052 512 5 00052 512 5 00052 512 5 00002 501 5 00002 501 5 00008 501 5 00023 529 5 00023 529 5 00061 513 5 00061 513 1 00110 130 1 00038 130 1 00038 130 1 00035 130 1 00038 130 1 00114 116 4 00650 426 4 00650 426 4 00592 425 4 00592 425 4 00592 425 4 00592 425 4 00008 440 7 00241 701 3 00026 325 3 00026 325 4 00041 401 4 00027 401 4 00041 401 4 00041 401 4 00041 401 4 00034 401 4 00034 401 4 00027 401 4 00027 401 4 00086 401 4 00065 401 4 00034 401 4 00021 401 4 00079 401 4 00021 401 4 00034 401 4 00164 407 4 00138 407 4 00206 407 4 00057 401 4 00130 407 4 00185 407 4 00130 407 4 00057 401 4 00185 407 4 00034 401 4 00034 401 1U AXIAL 01U 01U 30 PIN DIL 40 PIN DIL 40 PIN DIL 20 PIN DIL 40 PIN DIL 10 PIN WHITE 10X150
5. Print String Disk Drive Test This key activates the knob test screen A circle with a marker is dis played Select one of the 4 speeds displayed in the menu Turning the knob will cause the marker to move around the circle verifying knob ac tion and direction Using a slow speed is best when checking direction of movement The Printer Test key activates a sub menu Printer Type Printer Type key selects the type of printer attached to the parallel printer port Any Epson compatible graph ics printer or HP LaserJet compatible printer is support ed Screen Dump Pressing this key will print the graphics screen on the printer This action is the same as using the PRINT key Print String Pressing this key prints a text string to the printer If the Print String test works but the Screen Dump test fails then the printer probably does not support the Epson or HP LaserJet graphics mode Return The Return key will return to the Test menu Pressing this key activates the disk drive test screen Continuing with this test will destroy any data on the disk currently in the drive Therefore remove any disk containing data from the drive and insert a scratch disk This test will check the controller format the disk and read and write data to the disk The entire test takes approximately 2 minutes Use the Return function to skip this test and return to the previous menu 70 More RS 232 Test LI Memory Test L
6. Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Pot Multi Turn Trim 3 8 Square Printed Circuit Board Transistor TO 72 Package Transistor TO 46 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Comp 1 2W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbo
7. Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg nn nn nn nn nnn nn nn nn nnn nn nn nj NT Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg OO Poari 15 IILILCILLPI PeIALLEU LLLALALIALAUGOGOAAADLGLOZO4 QQL LALGL U 906 U 907 U 908 X 101 X 701 X 801 X 901 X 902 3 00109 340 3 00353 340 3 00040 340 6 00068 620 6 00015 620 6 00069 620 6 00068 620 6 00037 620 0 00192 015 1 00087 131 1 00136 171 1 00137 165 ME POWER SUPPLY BOARD REF SRS part C 1 5 00124 526 C2 5 00124 526 C3 5 00229 521 C4 5 00229 521 C5 5 00230 550 C6 5 00230 550 C7 5 00231 537 C9 5 00023 529 C 10 5 00023 529 C11 5 00002 501 C 12 5 00002 501 C 13 5 00002 501 C 14 5 00002 501 C 15 5 00027 503 C 16 5 00027 503 C 17 5 00027 503 C 18 5 00027 503 C 19 5 00002 501 C 20 5 00038 509 C 21 5 00098 517 C 22 5 00100 517 C 23 5 00100 517 C 24 5 00100 517 C 25 5 00100 517 C 26 5 00002 501 C 27 5 00038 509 C 28 5 00098 517 C 29 5 00038 509 C 30 5 00098 517 C 31 5 0
8. Using Photomultiplier Tubes flections from the input to the preamplifier A good starting point for a snubber network is a 10 inch piece of RG174 U coax cable with a small 50 Ohm pot connected to the end so that the termi nating impedance may be adjusted from 0 to 50 Ohms A 10 inch cable will have a round trip time of about 5 ns be sure your PMT has a risetime less than this The other end of this cable is con nected to the anode of the PMT together with the output signal cable Output current pulses will split 50 going out the signal cable and 50 going into the snubber If the snubber pot is adjusted to 50 Ohms there will be no reflection the only affect the snubber has is to attenuate the signal by a factor of two The reflection coefficient for a cable with a charac teristic impedance RO terminated into a resistance Rt is given by Reflection Coefficient Rt RO RO If the pot is adjusted to a value below 50 Ohms then some portion of the signal will be inverted and reflected back toward the anode This reflect ed and inverted signal is delayed by the round trip time in the snubber cable and sent out the sig nal cable The amount of the reflection is adjusted for the best pulse shape as shown in the figure be low The round trip time in the snubber cable may be adjusted so that the reflected signal cancels anode signal ringing This is done by using a cable length with a round trip ti
9. 01U 10X150 01U 4 7KX9 4 7KX9 4 7KX9 4 7KX9 500 SR430 TTL 2N5210 2N5210 150 1 5K 150 150 150 10K 10K 1 5K 1 5K 51 3 3K 10K 1 0K 4 7K 1 0K 10K 20 0K 10 0K 8 06K 220 1 00K 4 02K 1 00K 220 4 02K 10K 10K 140 Capacitor Ceramic 50V 80 20 Z5U AX Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Mylar Poly 50V 5 Rad Capacitor Mylar Poly 50V 5 Rad Connector Male Connector Male Connector Male Connector Male Connector Male Header Amp MTA 156 Resistor Capacitor Network Resistor Capacitor Network Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Trim Pot Single Turn In Line Leads Printed Circuit Board Transistor TO 92 Package Transistor TO 92 Package Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1
10. AD96685 MC10H107 MC10H116 SP4633 MC10H125 74HC4046 LF411 74HC191 25 000 MHZ MC10H102 MC10H131 MC10H131 MC10H131 MC10H131 MC10H131 MC10H125 MC10H102 MC10H131 MC10H131 MC10H131 MC10H131 MC10H131 MC10H109 MC10H158 MC10H158 MC10H106 MC10H125 74HC294 MC10H125 MC10H131 MC10H131 MC10H125 74F74 74F191 74HCT191 74HCT191 7AHCT74 74HCT32 74HCT374 74F374 MC10H107 137 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Crystal Oscillator Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrate
11. If the data has been converted to floating point BINB will cause an error BINB returns the entire data record 2 bytes per bin starting with bin 0 and continuing to the last bin in the record There is no separation be tween data points A line feed follows the last data point Each data point is sent low byte first then high byte The 2 bytes represent the data point in 16 bit 2 s complement format When using the BINB command the host interface must be capable of binary transfer i e accepting line feeds and carriage returns as data rather than terminators In addition the host program must read exactly the correct number of bytes number of bins per record times 2 plus the last line feed If BINB is used to while the unit is BUSY and a scan is in progress the entire record will be transferred before the display memory buffer is up dated The data acquisition memory will continue to acquire data at the trigger rate and will be transferred to the display buffer when the BINB transfer is complete 90 Remote Programming INTERFACE CONTROL COMMANDS RST IDN LOCL i The RST command resets the SR430 to its default configurations The communications setup is not changed All other modes and settings are set to their default conditions and values The IDN query returns the SR430 s device identification string This string is in the format Stanford Research Systems SR430 s 00001 007 In this example t
12. Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg STATIC RAM I C STATIC RAM I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg STATIC RAM I C STATIC RAM I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg ntegrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Pari 15 EEEEEREIILLHLIIIIUUUGILUIIIULLULILILUIUILIIBGILLICZI eIICOLILLGC Y LUILLL GUUGGGAASA OAOA AA OOO G QUAM U L0 U 1308 U 1309 U 1408 U 1602 U 1603 U 1604 3 00049 340 3 00049 340 3 00155 340 3 00059 340 3 00087 340 3 00076 340 _ SRS F5 6 00004
13. Screen Test O Return RS 232 Test Memory Test Main Video L Hj Screen Test Test Menu The More key activates the second Test menu described below Pressing this key activates the RS232 test screen A special loop back adapter is required to complete this test The loop back adapter is simply a mating connector with pins 2 and 3 connected so characters transmit ted by the interface will be received by the instrument The Memory Test key activates a memory test sub menu Select the de sired memory test Main Memory Video Memory Return Pressing this key tests the program ROM and data RAM on the CPU board The data acquisition memory is not tested See the Test and Calibration section for more in formation on testing the data acquisition hardware Pressing this key tests the video display RAM A video pattern will scroll through the display while the test is done The Return key will return to the Test menu This key displays a test pattern on the screen 71 Test Menu 72 INFO MENU Introduction About the SR430 LI About SRS Operating Hints List Status L Bytes Fundamental Constants About the SR430 About SRS Operating Hints Command List Status Bytes Fundamental Constants The Info menu displays various information screens which may be help ful to the user This key displays the SR430
14. Since most commands execute very quickly the host comput er does not need to continually check the Interface Ready bit Commands may be sent one after an other and they will be processed immediately However some commands such as file com mands and math operations may require a long time to execute In addition the host program may need to check that these operations executed without error In these cases after the command is sent the Status Bytes should be queried When using the GPIB interface serial polling may be used to check Interface Ready bit in the Serial Poll Byte while an operation is in progress After the Interface Ready bit becomes set signalling the completion of the command then the ERR bit may be checked to verify successful completion of the command If the RS232 interface is used or serial polling is not available then the STB ESR ERRS and MCSS status query commands may be used to query the Status Bytes Since the SR430 pro cesses one command at a time the status query will not be processed until the previous operation is finished Thus a response to the status query in itself signals that the previous command is fin ished The query response may then be checked for various errors For example the command line SVTR ERRS 80 lt lf gt will save the data to disk and return the Error Status Byte when finished The Disk Error bit may be checked to make sure that the Save Trace command t
15. U310 allows whichever flip flop clocks first to lock out the other U308D then outputs a 200 MHz clock which has at most 2 5 ns of indeterminacy with respect to the trigger The output of U308D is then the master clock for this trigger U311B di vides the clock to 100 MHz and U313B divides to 50 MHz Q303 and Q304 provide the 50 MHz TEST signal When all of the bins for the record have been generated the signal DONE ECL re sets U311A and U311B which disables the clocks This turns off the BIN CLK output and TEST out put BIN CLOCK GENERATOR When the bins clocks are being generated inter nally the 100 MHz output of U311B feeds a divid er chain made up of U402AB U403AB U404A and U412 U402 U403 and U404 are ECL flip flops which divide by 2 They are enabled by con trol lines BO B3 to provide divide by 2 4 8 16 or 32 U412 is a TTL divider which can divide by 2 through 2 15 by programming the A D inputs The input to U412 is 6 25 MHz and the last output of U412 can be as low as 1906 7 Hz The divider out puts are combined in U407B to give an output pulse which is synchronous with the 100 MHz clock and lasts for 10 ns The output of U407B has a frequency range from 50 MHz to 1906 7 Hz in bi nary steps U404B divides this frequency by 2 U405AB di vides the frequency by 2 again and provides 4 out puts which are 90 degrees apart in phase U406AB synchronize these outputs with the 100 MHz clock once again At the highest
16. Z0 0 00186 021 6 32X1 3 8PP Screw Panhead Phillips 20 0 00187 021 4 40 1 4 Screw Panhead Phillips Z0 0 00231 043 4 SHOULDER Washer nylon Z0 0 00246 043 8 X 1 16 Washer nylon Z0 0 00309 021 8 32X1 4PP Screw Panhead Phillips 20 0 00316 003 PLTFM 28 Insulators Z0 7 00285 721 PLTFM 21 Machined Part Z1 0 00158 000 60MM 24V Hardware Misc SEES LOGIC BOARD REF SRS part VALUE DESCRIPTION C316 5 00215 501 20P Capacitor Ceramic Disc 50V 10 SL C 1 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C2 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C3 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 4 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C5 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C6 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C7 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C8 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C9 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 10 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 11 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 12 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 13 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 14 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 15 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 16 5 00225 548 1U AXIAL Capacitor
17. and scal ing parameters from the file specified in the File Name field If the file specified is not on disk or is not a trace file then an error message will appear This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are read from the root directory This key toggles the file catalog display screen on and off The file catalog display lists all files currently in the root directory A sample catalog screen is shown below The first file will be highlighted and the file name will ap pear in the File Name field Activating the cursor by pressing the CURSOR key allows the knob to scroll through the directory The highlighted file name will be copied into the File Name field If the Recall Trace key is now pressed the data in the highlighted file will be read Directory entries made by the SR430 also have a type field shown in the catalog display Files with type SET bin 71 727 0 usec Recall Y 50 cnts Trace L Type Size Date 06 24 88 15 47 22 SET 40 08 10 89 10 47 25 SPEC1 DAT TRC 4192 08 10 89 11 08 27 SPEC2 DAT TRC 4192 10 15 89 11 21 01 MYDATA DAT 4144 10 15 89 11 46 32 bin 0 0 msec bottom 0
18. difficult to implement 3 If the average count rate is low but the peak count rate is high then bypass capacitors on the last few stages may be used to prevent the dy node voltage from dropping Use 20x the aver age output current for the chain current For a voltage drop of less than 1 the stored charge on the last bypass capacitor should be 100x the charge output during the peak count rate For ex ample the charge output during a 1 ms burst of a 100 MHz count rate each with an amplitude of 10 mV into 50 Ohms and a pulse width of 5 ns is 0 1 uC If the voltage on the last dynode is 200 Vdc then the bypass capacitor for the last dynode should have a value given by C 100 QN 100 x 0 1uC 200V 0 05 uF The current from higher dynodes is smaller so the capacitors bypassing these stages may be small er Only the final four or five dynodes need to be bypassed usually with a capacitor which has half the capacitance of the preceding stage To reduce the voltage requirement for these capacitors they are usually connected in series See Figure B By passing the dynodes of a PMT may cause high PHOTOCATHODE HIGH VOLTAGE 8 DYNODES Using Photomultiplier Tubes frequency ringing of the anode output signal This can cause multiple counts for a single photon The problem is significantly reduced by using small re sistors between the dynodes and the bypass ca pacitors as shown in Figure B SNUBBING Snubb
19. highlight a different parameter field or to toggle a setting or the CURSOR key is pressed to high light the cursor field or a new menu key is pressed before ENTER is pressed the displayed entry will be cleared and the original value re stored Whenever a parameter entry field is highlighted the knob may also be used to adjust the value If the knob is turned during numeric entry before the ENTER key has been pressed the value will be adjusted starting from the original value CURSOR Pressing the CURSOR key highlights the cursor information field by drawing a box around it The knob will now scroll the cursor region The CUR SOR key highlights the cursor field in the same way that a soft key would highlight a parameter field The highlighted cursor field appears below Any previously highlighted parameter field will be come non highlighted and any entry in progress is cancelled Pressing a soft key to highlight a pa rameter field will let the knob adjust the new pa rameter while the cursor will become de selected AUTOSCALE Pressing AUTOSCALE will automatically set the vertical scale and translation to display the entire range of the data The graph will also be translat bin 71 Y 50 cnts Trigger 500 mV ed so that the it is centered AUTOSCALE does not affect the horizontal scaling or translation While autoscaling is taking place the message AutoScaling will appear just below the graph I
20. program boot firmware This memory is mapped at E0000H to FFFFFH 128k U303 and U304 are data ROMS mapped at 80000H to 9FFFFH 128k U401 and U402 are 32kbyte CMOS static RAMs mapped at 00000H to OFFFFH 64k This memo ry is backed up by the battery Q401 provides power down RAM protection This memory is sys tem memory 116 U403 and U404 are also 32kbyte static RAMs They are mapped at 40000H to 4FFFFH 64k and are used as the display data memory Up to 16k data points may be stored in this memory Data stored in this memory may be graphed on the screen 4 of the 7 80C186 s peripheral chip select strobes are used by peripherals on the CPU board PCSO is decoded into 16 IO strobes which access the clock keypad keyboard knob printer port etc PCS1 decodes the disk controller the GPIB con troller and DMA acknowledge strobes PCS2 se lects the UART and PCSS selects the video graphics controller Whenever the video controller is accessed the ARDY line is asserted U504A which puts the processor into a wait state When the video controller acknowledges the data trans fer by pulling Video Rdy low the ARDY line is de asserted U805A and U815D and the proces sor moves on to the next instruction Interrupts generated by peripherals on the CPU board are combined in U505 into a single priori tized interrupt The highest priority pending inter rupt will be encoded on U505 s outputs and read via the status port
21. 40 C R4 becomes a high resistance and some of the 10 mA will go into the base of Q2 turning speeding up the fan Diode D13 keeps the fan at half speed even when cool The proportional temperature control can double the fan speed if necessary ECL LOGIC BOARD The ECL Logic Board contains the discriminator high speed counters and bin clock generator 8 bits of count data can be provided every 40 ns to the TTL Logic Board for storage in data acquisition memory SIGNAL INPUT The signal input passes through the signal amplifi er The amplifier has a DC to 250 MHz bandwidth and a gain of 5 over an input range of 300 mV The inputs are protected to 5VDC and 50V tran sients R102 R103 R104 P101 D101 D102 and D103 comprise an overload protection circuit which clamps the amplifier input to x350mV AC gain is provided by Q101 and Q102 and is compensated by C104 U101 sets the DC gain Q102 sums the AC and DC signals and can drive its100 output to 2V U102 D105 and Q103 provide a tempera ture compensated bias voltage for the overload protection circuits which is adjusted by P101 to null the DC offset at the input DISCRIMINATORS Comparator U202 discriminates the amplified sig nal into ECL levels The threshold is provided by analog voltage SIGLVL and buffered by U201A The output transistor Q202 provides a high fre quency low impedance output The comparator is operated in the Schmitt trigger configuration with abo
22. 50PPM R33 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 34 4 00034 401 10K Resistor Carbon Film 1 4W 5 R35 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 36 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 38 4 00081 401 470 Resistor Carbon Film 1 4W 5 R 39 4 00149 407 121 Resistor Metal Film 1 8W 1 50PPM R 40 4 00179 407 30 1K Resistor Metal Film 1 8W 1 50PPM R 41 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 42 4 00188 407 4 99K Resistor Metal Film 1 8W 1 50PPM R 44 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 45 4 00169 407 249 Resistor Metal Film 1 8W 1 50PPM R 46 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 47 4 00048 401 2 2K Resistor Carbon Film 1 4W 5 R 48 4 0021 1 407 9 53K Resistor Metal Film 1 8W 1 50PPM R 49 4 00199 407 6 81K Resistor Metal Film 1 8W 1 50PPM R 50 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 51 4 0021 1 407 9 53K Resistor Metal Film 1 8W 1 50PPM R 52 4 00199 407 6 81K Resistor Metal Film 1 8W 1 50PPM R 53 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 54 4 0021 1 407 9 53K Resistor Metal Film 1 8W 1 50PPM R 55 4 00199 407 6 81K Resistor Metal Film 1 8W 1 50PPM R 56 4 00130 407 1 00K Resistor Metal Film 1 8W 1 50PPM R 57 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R 58 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R 59 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R 60 4 006
23. 721 7 00270 735 7 00272 735 7 00275 740 7 00276 720 7 00277 711 7 00281 720 7 00284 720 7 00286 720 7 00287 721 7 00289 720 7 00291 709 7 00292 720 7 00350 720 7 00396 701 7 00414 720 7 00431 720 7 00435 720 4 40X1 2 M F 8 32X1 4PF CLIP CABLE SWITCH 23 18 BLACK 23 18 RED 554808 1 3 18 13 18 8 32X3 8PF 10 PIN 18AWG OR BNC 5 PIN 18AWG OR INSL 4 PIN SIL 30 PIN DIL 20 PIN 18AWG OR 3 PIN 18AWG OR 4 PIN DIF DISK 20 COND 30 COND DIL 34 COND 40 COND 40 COND 5 PIN SI 5 PIN SIL 20 COND 12 PIN SIF DPDT ENA1J B20 SAS50B 100K SG240 PLATFORM 2 SPKR 2 HOLE TRANSCOVER2 MOD PLTFM 4 PLTFM 7 PLTFM 9 SR430 SR430 20 SR430 21 PLTFM 18 PLTFM 20 7 CRT SCREEN PLTFM 23 PLTFM 26 SR430 23 TO 25 PLTFM 27 PLTFM 29 PLTFM FP SR770 17 SR770 21 22 SR770 26 Standoff Screw Flathead Phillips Hardware Misc Hardware Misc Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Hardware Misc Wire 18 UL1015 Strip 3 8 x 3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Screw Black All Types Connector Amp MTA 156 Connector BNC Connector Amp MTA 156 Connector BNC Cable Assembly Ribbon Connector Male Connector Amp MTA 156 Connector Amp MTA 156 Connector Female Cable Assembly Ribbon Cable Assembly Ribbon Cable Assembly Ribbon Cable Assembly Ribbon Cable Assembly Ribbon Connector Male Cable Assembly Ribb
24. Capacitor Tantalum 35V 20 Rad Capacitor Electrolytic 50V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Poari 15 EEEEEREILLILILIUIIIIIIIIIGIULLLILIUL IULLILILIULLILII LTEACLLLOoO 4ACGSGGGGGGUGSuLLAe 17 F LTDLEGLLLSULUL 1 C 36 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 37 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 38 5 00098 517 10U Capacitor Tantalum 35V 2096 Rad C 39 5 00098 517 10U Capacitor Tantalum 35V 2096 Rad C 40 5 00098 517 10U Capacitor Tantalum 35V 2096 Rad C 41 5 00098 517 10U Capacitor Tantalum 35V 2096 Rad D2 3 00391 301 MBR360 Diode D3 3 00391 301 MBR360 Diode D 4 3 00391 301 MBR360 Diode D 5 3 00391 301 MBR360 Diode D 6 3 00226 301 1N5822 Diode D7 3 00226 301 1N5822 Diode D8 3 00226 301 1N5822 Diode D 9 3 00226 301 1N5822 Diode D 10 3 00226 301 1N5822 Diode D 11 3 00226 301 1N5822 Diode D 12 3 00181 340 RS401LR ND Integrated Circuit Thru hole Pkg D 13 3 00001 301 1N4001 Diode D 14 3 00004 301 1N4148 Diode D 15 3 00004 301 1N4148 Diode D 16 3 00004 301 1N4148 Diode D17 3 00004 301 1N4148 Diode D 18 3 00001 301 1N4001 Diode D19 3 00001 301 1N4001 Diode D 20 3 00001 301 1N4001 Diode D 21 3 00001 301 1N4001 Diode D 22 3 00001 301 1N4001 Diode D 23 3 00226
25. Ceramic 50V 80 20 Z5U AX C17 5 00225 548 1U AXIA Capacitor Ceramic 50V 80 20 ZBU AX C 18 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 132 Pari 15 EEEEEERERLLLLZIUUILIIUGULUIIIULUIUUILLIILLILTTISLILTILL LAULIULLOLLO u LLLULAGIRGGGSuI OOULUC OO LXLULL44G 4 C 19 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 20 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 21 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 22 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 C 23 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 24 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 25 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 26 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 27 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 C 28 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 29 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 30 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 31 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 32 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 33 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 34 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 35 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 36 5 00225 548 1U AXIAL Capacitor Cera
26. DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are read from the root directory This key toggles the file catalog display screen on and off The use of this key is identical to the Catalog On Off function in the Recall Trace sub menu above The Return key will return to the main Recall menu Re turn also removes the catalog display screen and re stores the graph The Recall System sub menu is used to read the SR430 system configu ration from a disk file All parameters in the Setup menu are read Recall ing System data does not affect any count data presently in memory Recall System File Name Catalog On Off Return Pressing this key will read the current system informa tion Setup menu data from the file specified in the File Name field This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are read from the root directory This key toggles the file catalog display screen on and off The use of this key is identical to the Catalog On Off functio
27. Display Data Display Cursor Display Menu Display Data Acquisition Status Status Indicators Keypad Normal and Alternate Keys START and STOP RESET Menu Keys Entry Keys CURSOR AUTOSCALE PEAK CENTER NORM PRINT HELP LOCAL23 Rear Panel Power Entry Module IEEE 488 Connector c0 25 25 25 RS232 Connector Parallel Printer Connector PC Keyboard Connector BNC Connectors MENUS Levels Menu Mode Menu Display Menu Setup Menu Save Menu Recall Menu Math Menu Plot Menu Test Menu Info Menu INSTRUMENT SETUPS Default Setup Power On Clear Choosing Bin Width amp Record Length Accumulation Using the Trigger Offset Using SYNC BUSY76 REMOTE PROGRAMMING GPIB Communications RS232 Communications Status Indicators and Queues Command Syntax Interface Ready and Status Detailed Command List Level Control Commands Mode Control Commands Display Control Commands Setup Commands Save and Recall Commands Math Operation Commands Print and Plot Commands Data Acquisition Control Commands Data Transfer Commands Interface Control Commands Status Reporting Commands Status Byte Definitions Serial Poll Status Byte Standard Event Status Byte MCS Status Byte Error Status Byte File Formats Printer Interface 117 Trace File 95 Video Graphics Interface 117 Settings File 95 Disk Controller 117 Program Examples 97 GPIB Interface 117 IBM PC BASIC RS232 97 RS232 Interface 117 Microsoft C Nat
28. During acqui sition the accumulation RAMs are disabled so the address does not matter The accumulation of a data point proceeds as fol lows When the new buffer address is clocked the present value of the accumulation at that address is read from the accumulation RAMs At the same time fast buffer data from that address is read from the even and the odd fast buffers The odd buffer data is enabled by U1001 and the even data by U1003 The high byte of count data comes di rectly from U805 since it holds both even and odd data The odd data is enabled into exclusive or gates U1020 U1023 These gates are used to comple ment the incoming data for subtraction The out puts of the XOR gates is fed into 4 4 bit adders U1006 U1009 The other input to the adders is the accumulation data from U1012 and U1013 The output of the adders is the sum of the accumula tion with the new data and is latched into U1010 and U1011 The accumulation RAMS are then put into the write mode the outputs of U1010 and U1011 are enabled and the new accumulation is written into RAM at the same address The process repeats itself for the even data The lowest address bit of the accumulation RAM is the even odd selection bit After the even data is fin ished the address is clocked to next address and the odd data is accumulated again This repeats until DONE is active and all bins have been accu mulated For the case of 5 ns bin widths each byte of data
29. LEVELS menu appropriately for the trigger source Use a 5 foot length or longer BNC cable to connect the TEST output on the rear panel to the SIGNAL input on the front panel Set the Disc Level to 300 mV and the Disc Slope to Falling Set the trigger rate to 1 kHz Press the START key Data acquisition should begin The default bin width is 5 ns and the record length is 1k 1000 records will be accumulated When the scan is done press AUTOSCALE to scale the display The TEST output is a 50 MHz signal so a pulse occurs every 20 ns or every 4 bins The data should have 1000 counts in every 4th bin Use the Mode menu to select different bin widths and records per scan Records with longer bin widths trigger at lower rates so the trigger rate needs to be lowered to avoid RATE errors Use the formula for Tbusy in the Specifications section of the manual to calculate the maximum trigger rate for each bin width and record length Longer bin widths also require a smaller number of records per scan to avoid overflow This is be cause each bin acquires a larger number of counts per trigger Bin widths of 40 ns and longer will collect data in every bin The first bin may have 1 less count per trigger than the other bins For longer bin widths 163 us or longer the data may vary up to 7 counts per bin per trig ger This is due to the jitter in the longer bin widths After acquiring data use the other menus to scale the data smooth or perform calculations wi
30. LL LWLLGU GIO R7 4 00034 401 10K Resistor Carbon Film 1 4W 596 R8 4 00305 401 4 3K Resistor Carbon Film 1 4W 5 R 9 4 00046 401 2 0M Resistor Carbon Film 1 4W 5 R10 4 00065 401 3 3K Resistor Carbon Film 1 4W 5 R11 4 00185 407 4 02K Resistor Metal Film 1 8W 1 50PPM R12 4 00470 407 10 5K Resistor Metal Film 1 8W 1 50PPM R13 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R14 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R15 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 16 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R17 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 18 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R19 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 20 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 21 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 22 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 23 4 001 72 407 26 1K Resistor Metal Film 1 8W 1 50PPM R 24 4 00054 401 200K Resistor Carbon Film 1 4W 5 R25 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 26 4 001 72 407 26 1K Resistor Metal Film 1 8W 1 50PPM R27 4 00054 401 200K Resistor Carbon Film 1 4W 5 R 28 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 29 4 00164 407 20 0K Resistor Metal Film 1 8W 1 50PPM R 30 4 00054 401 200K Resistor Carbon Film 1 4W 5 R 31 4 00054 401 200K Resistor Carbon Film 1 4W 5 R 32 4 00493 407 12 4K Resistor Metal Film 1 8W 1
31. SYNC BUSY and BIN CLK are inactive When the data acquisition is DONE the final accu mulated data is displayed on the screen and may be analyzed and manipulated Before taking data again the current data must be cleared by press ing the STOP RESET key or sending the RESET command via the computer interface This will clear the count memory and the display The unit will now be in the CLEAR state While in the CLEAR state the data acquisition setup may be altered A new record length or bin width may be programmed etc The START key will start data acquisition once again and put the unit in the BUSY state ADD SUBTRACT TOGGLE and INHIBIT Normally records are accumulated by summing corresponding bin data from successive records Records may also be subtracted from the accumu lation The accumulation mode may be set to ADD SUBTRACT TOGGLE or EXTERNAL ADD will sum new records to the accumulation SUBTRACT will subtract new records from the ac cumulation Instrument Overview TOGGLE will switch between ADD and SUB TRACT every M records where M is programma ble In this mode the rear panel TOGGLE OUT PUT will be TTL high before the trigger of those records which will be subtracted EXTERNAL will subtract records whenever the ex ternal SUBTRACT INPUT is TTL high The SUB TRACT INPUT is sampled at the trigger and will determine whether that record will be added or subtracted The rear panel INHIBIT INPUT is u
32. U608 The UART directly inter rupts the processor since it can never be masked KEYPAD INTERFACE The keypad is organized as 8 columns and 8 rows of switch closures The conductive rubber keys provide the switch closures U607 strobes the col umns and U606 detects the switch closure The diodes D601 D608 prevent one column from af fecting another All of the outputs from U607 are set high and U606 is read periodically by the pro cessor As long as 00H is read no key is pressed and the strobes are left on When a non zero byte is read then the key strobes are activated individ ually in order to decode which key is down KEYBOARD INTERFACE The PC keyboard interface uses U603 to convert serial data from the keyboard into a parallel byte for the processor to read The data format from the keyboard is a leading start bit followed by 8 data bits U603 is reset by a processor read When a key is pressed the bits are shifted into U603 When the start bit appears at the QH output 7 bits of the data byte are in U603 U601 is the 9th bit of the shift register When U601 clocks in the start bit U601 must have the 8 bits of the data U601 then latches the serial data in U601 and interrupts the processor Only keyboards which operate in the PC or 8088 mode will function with this interface SPIN KNOB The knob is an optical encoder buffered by U612 Each transition of its outputs is clocked into U610 or U611 and generates an interrup
33. be terminat ed at any time by pressing the Abort key When the fit terminates the best fit curve is plotted and the parameters of the fit are displayed at the bottom of the screen Pressing any key to continue will restore the graph to normal See View Parameters below for a description of each fit The View Parameters function displays the most recent curve fit and pa rameters For example if a fit was performed and then the Fit menu exit ed the fit will be erased from the screen If the graph is then scaled dif ferently using the Display menu and then the Fit menu re entered the curve fit is redrawn The View Parameters function re displays the pa rameters Both the Do Fit and View Parameters functions result in a display screen 61 Math Menu Left and Right Limit like the one shown below In this example screen the fit is a line The curve fit region is delimited by FARM 7 _ bj ES ES ES BE iH ES is eae ee to 33 bins 337 9 hsec 6 612456e 001 MODE o 5 974026e 001 5 834009e 004 s to Continue the two limit markers heavy dashed vertical lines as described below The final curve fit is plotted between the limit markers along with the data The parameters of the fit are displayed at the bottom of the screen Each type of fit line exponential or Gaussian has a different parame ters display The horizontal coordinate is t in bins or time
34. bin widths are required for resolution The More key displays the second Mode menu This menu sets the ac cumulation mode and also reacquires displayed data from the data ac quisition memory The Accumulate key selects the accumulation mode ADD mode sums new record data to the accumulation The maximum accumulation per bin is 32 767 EXT and TOGGLE can either add to or subtract from the accumulation When either of these modes is selected the maximum ac cumulation per bin is 16 383 EXTernal mode means that the SUBTRACT input will determine whether each record is added or subtracted If SUBTRACT is high when a record is triggered then that record s data is subtracted from the accumulation TOGGLE mode will switch between ADD and SUBTRACT after every Toggle Count number of records In this mode the TOGGLE output will be TTL high when the next record is to be subtracted and TTL low when the next record is to be added The TOGGLE output switches at the end of SYNC BUSY to reflect the accumulate mode of the next triggered record When data acquisition is started the first toggle count number of records is added before switching to subtract The Add Sub status indica tor on the screen shows the toggle status during a scan Toggle is gener ally used for background subtraction 31 Mode Menu Toggle Count Pause at Toggle ReAcquire From Offset This key is active only if the Accumulate Mode is set to Toggle The Tog gle Coun
35. case and may contain any number of em bedded space characters A command to the SR430 consists of a four character command mnemonic arguments if necessary and a com mand terminator The terminator must be a line feed lt gt or carriage return cr on RS232 or a linefeed If or EOI on GPIB No command pro cessing occurs until a command terminator is re ceived Commands function identically on GPIB and RS232 whenever possible Command mne monics beginning with an asterisk are IEEE 488 2 1987 defined common commands These commands also function identically on RS232 Commands may require one or more parameters Multiple parameters are separated by commas Multiple commands may be sent on one command line by separating them with semicolons The difference between sending several commands on the same line and sending several independent commands is that when a command line is parsed and executed the entire line is executed before any other device action proceeds There is no need to wait between commands The SR430 has a 256 character input buffer and pro cesses commands in the order received If the buf fer fills up the SR430 will hold off handshaking on the GPIB and attempt to hold off handshaking on RS232 Similarly the SR430 has a 256 character output buffer to store output until the host comput er is ready to receive it If either buffer overflows both buffers are cleared and an error reported The pr
36. cnts File Name ABCD Catalog Free 710760 Sn o bin 127 1 300 msec 10 cnts Div Record 100 Return 7 54 Return Recall Menu are settings type SYS are system and type TRC are trace data The file type is not an extension but is infor mation stored in the directory on the disk Only files created by the SR430 have a type Files created and saved on a DOS computer will not have a type dis played The file type is not necessary it is only an aid to identifying files The Return key will return to the main Recall menu Re turn also removes the catalog display screen and re stores the graph 55 Recall Menu Recall Settings Recall seins L File Name TEST DAT Catalog On Return Recall System Recall sn File TEST DAT Catalog On Return The Recall Settings sub menu is used to recall the settings in the Levels and Mode menus i e the hardware configuration of the data acquisition system from a disk file Settings may not be recalled unless the unit is in Recall Settings File Name Catalog On Off Return the CLR state data memory is reset Pressing this key will read the settings information Lev els and Mode menu data from the file specified in the File Name field This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered
37. drawback though Because the data can now be positive and negative the count range is restricted to 16384 instead of 32767 However background accumulation is eliminated USING THE TRIGGER OFFSET If the desired bin width results in the time of inter est occurring more than 16k bins after the trigger the trigger offset must be used The number of bins acquired is equal to the sum of the trigger off set and the number of bins per record and can be as large as 32k The SR430 can only display 16k data points at a time The trigger offset is used to skip bins in the data acquisition memory and dis play only the region of interest The trigger offset essentially delays the trigger by a number of bins If a delay larger than 32k bins is required then a delay generator is needed to delay the actual trig ger pulse USING SYNC BUSY After a trigger is recognized the SYNC BUSY out put will go high indicating the start of the first time bin The insertion delay from TRIGGER to SYNC BUSY is 45 ns SYNC BUSY will have 2 5 ns of in determinacy with respect to the trigger As a re sult the entire record starts with 2 5 ns of uncer tainty with respect to the trigger This is not a problem if the bin width is much longer than 2 5 ns but may be a problem for shorter bin widths In these cases the SYNC BUSY output should be used to trigger the experiment Since the record is synchronized to SYNC BUSY there will be no in determinacy of t
38. highlighted by a soft key The MENU keys select a menu of soft keys Pressing a menu key will change the menu boxes which are displayed next to the soft keys Each menu groups together similar parameters and functions The CONTROL keys start and stop ac tual data acquisition select the cursor and auto scale the display These keys are not in a menu since they are used frequently and while display ing any menu The SYSTEM keys print the screen to a printer and display help messages Once again these keys can be accessed from any menu A complete description of the keys follows in the next section SPIN KNOB The spin knob is used to adjust parameters which have been highlighted using the soft keys Any nu meric entry field may be adjusted using the knob In addition functions such as display zooming and scrolling use the knob as well In these cases the knob function is selected by the soft keys The CURSOR key which can be pressed at any time will set the knob function to scrolling the cursor DISK DRIVE The 3 5 disk drive is used to store data and instru ment settings Double sided double density disks should be used The disk capacity is 720k bytes formatted The disk format is DOS compatible Disks written by the SR430 may be read by PC compatible computers equipped with a 3 5 drive and DOS 3 0 or higher 16 BNC CONNECTORS TRIGGER The rising or falling edge of the TRIGGER input triggers a record The inpu
39. hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg nnn nn nn V V nnn nn p nw V nT OT DESCRIPTION Capacitor Tantalum 35V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 250 AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Poari 15 EEEEEREILLLLIGIUILIIUGULUIIIULLILUILIUIILLIIG LIP I UICCBGSuH LUOALLULI CGUGQGGGGHUuuNLLOAALLLULLL GGI J C 10 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C11 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 12 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 13 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 250 AX C 14 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 15 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 16 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 17 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 18 5 00225 54
40. in a accumulation dead time of 250 ns X number of bins in the record 8 ms for 32k bins After the accumulation is complete the memory is re armed for the next trigger The number of records accumulated is programmable 1 to 65 535 or free run The count capacity is 32 767 per bin per trigger The total accumulation capacity per bin is also 32 767 The SYNC BUSY output for each record remains high from the trigger until the end of accumulation When SYNC BUSY returns low another trigger can be received The SR430 offers advanced functions such as Autoscale Smoothing Curve Fitting non volatile setup mem ories data storage to disk push button hardcopy to graphics printers and plotters and GPIB and RS 232 in terfaces The SR430 is also easy to use It has a menu based user interface which makes front panel adjust ments intuitive and straightforward Entries are made with the front panel knob or numeric keypad On screen help is available at all times SPECIFICATIONS SIGNAL INPUT Bandwidth dc to 250 MHz Input impedance 50 Linear range 300 mV at input Input protection 5 VDC 50 V for 1 us Overload recovery 5 ns for lt 10 us duration overload DISCRIMINATOR Referred to the signal input Discriminator range 300 mV to 300 mV Resolution 0 2 mV Slope Positive or Negative Accuracy 2mV 1 Minimum pulse input amplitude 10 mV Pulse pair resolution 10 ns typical DISC view output NIM level into 50 There is a 20 ns insertion del
41. is safe only if the LED is OFF If the LED is ON then STAY AWAY from the power supply board This unit is to be serviced by qualified service personnel only 105 Test and Calibration WARNING The calibration procedure requires adjusting the instrument with power applied and so there is a risk of personal injury or death by electric shock Stay away from the power supply board while the unit is plugged in Please be careful Turn the power off disconnect the power cord wait two minutes then remove the top cover of the chassis Plug the unit back in and turn on the pow er SIGNAL INPUT OFFSET To calibrate the input offset connect a voltmeter to the signal input P101 adjusts the voltage which is output from the signal input This output voltage should be set to OV The potentiometer is located on the ECL board lower board behind the signal input BNC Use a small screwdriver from the top and adjust the potentiometer for a reading of 0 0 1 mV on the meter SIGNAL INPUT REPAIR The diodes in the overload protection circuit can be damaged by excessive voltages at the inputs To check for damage measure for 0 6 V across the diodes in D101 D102 and D103 can be tested by removing them from the circuit and then check ing for degradation of the amplifiers pulse re sponse as each diode is reconnected The amplifi er outputs can be viewed with a fast oscilloscope across R239 Replacement diodes are available from th
42. is shown as a horizontal line at the correct Y position The graph above shows data in this mode When the number of bins exceeds 496 then each X screen location on the graph corresponds to multiple bins The data is then displayed as a vertical line at each X screen location The displayed line con nects the maximum and minimum values of the data points at each X screen location The Left most displayed bin and time is the X val ue corresponding to the left edge of the graph Guide To Operation The Right most displayed bin and time is the X value of the right edge of the graph These values represent the X scale and translation The X scale is Right Left 10 per division The horizontal scale ranges from 16 bins to N bins across the graph The actual position of the displayed data within the record is given by the Left and Right values Bin 0 is the first bin in the record and Bin N 1 is the last bin where N is the programmed number of bins per record The Left and Right values mark the region of the record displayed on the graph The graph may be horizontally translated in incre ments of 1 100 of the screen or 1 bin whichever is larger The Vertical scale is the number of accumulated counts per division displayed on the graph This value is changed whenever the vertical scale is adjusted The vertical scale ranges from 1 to 5000 counts per division The Minimum displayed Y value corresponds to the Y value of the bottom edge o
43. of data CONTROL SIGNALS The control signals come from the TTL Logic board via the connector JP1602 U1501 U1503 are TTL to ECL level shifters to provide ECL con trol lines JP1601 carries the data from the counter data latches to the TTL Logic board 121 Circuit Description TTL LOGIC BOARD The TTL Logic board contains the data acquisition memory and bin counters as well as the accumula tion circuitry FAST RECORD BUFFERS The fast record buffers store the points from the counters as the data is acquired in real time The lower 8 bits of the memory must be able to store in 40 ns U801 U804 are 8kbyte 40 ns static RAMs which can store 32k points of the lower 8 bits of the count data U805 is a single 32kbyte static RAM which can store 32k points of the upper 8 bits of count data The upper 8 bits are active only for longer bin widths when the store and reset times are longer While the record is being ac quired U806 multiplexes the memory write signals to the fast buffer memories FAST BUFFER ADDRESS COUNTER Addresses for the fast buffers are generated by counters U908 U911 Before the trigger is armed the processor loads the number of bins in a record divided by 2 into the counter While data is being acquired the counter is clocked by LATCH ODD which occurs at half the bin frequency When the counter counts past zero the last output bit tog gles and the DONE signal is generated DONE disables the bin generato
44. of signal pulse heights coming from the PMT There is another distribution of noise pulse heights Noise which re sults from thermionic emission from the photoca thode can not be distinguished from signal howev er noise pulses from dynode thermionic emission will have a lower mean pulse height The PMT should be operated at sufficient high voltage that the mean signal pulse height is well above the pulse height of other noise sources such as preamp noise and EMI pickup There are two reasons for carefully selecting the input discriminator level The first is to improve the signal to noise ratio by setting the discriminator level above most of the noise pulses but below most of the signal pulses The second reason is to reduce drift if the discriminator threshold is set to the middle of the signal pulse height distribution then small changes in the tube gain can cause a large change in the count rate There is no exact prescription for setting the dis criminator threshold the procedure used will de pend somewhat on the nature of the measure ment If dark counts are a problem then the discriminator level should be set higher than when drift is a concern If the PMT is cooled reducing thermionic emission then a lower discriminator level is probably okay If the PMT has a ring on the anode signal then the discriminator level should be set high enough so that the rings are not counted 111 Using Photomultiplier Tubes THE
45. re stores the graph 49 Save Menu Save Settings Save seins L File Name TEST DAT Catalog On Return Save System Save sen File Name TEST DAT Catalog On Return The Save Settings sub menu is used to save the settings in the Levels and Mode menus i e the hardware configuration of the data acquisition system Save Settings File Name Catalog On Off Return Pressing this key will save the current settings informa tion Levels and Mode menu data to the file specified in the File Name field This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are saved to the root directory This key toggles the file catalog display screen on and off The use of this key is identical to the Catalog On Off function in the Save Trace sub menu above The Return key will return to the main Save menu Re turn also removes the catalog display screen and re stores the graph The Save System sub menu is used to save the SR430 system configu ration All parameters in the Setup menu are saved Save System File Name Catalog On Off Return Pressing this key wi
46. require no argument Pressing this key starts the actual calculation The Calculating mes sage appears below the graph while calculations are in progress The calculation uses the operation specified by the Operation key and uses the argument chosen by the Argument keys 64 Argument Type Argument 1 234 Cursor to Arg a Argument Cursor to Arg File Name SPEC2 DAT Catalog Off On File Name Return Catalog On Off Math Menu Note that many operations will require an AutoScale to display the result on the graph The Argument Type function selects between a constant argument and a data file on disk A constant argument adds or subtracts a constant or multiplies or divides by a constant A file argument uses a stored data file on disk as the argument In this case calculations are performed on a bin by bin basis i e bin 0 is added to bin 0 from disk bin 1 is added to bin 1 from disk etc Calculations continue from bin 0 until the last bin of either the displayed data or the disk file In the case of divide the displayed data is divided by the disk data If the Argument type is a constant then the Argument and Cursor func tions are displayed Pressing the Argument key activates the constant argument entry field Use the keypad to enter a numerical argument Integer 3 real 3 0 or floating point 0 3E 1 formats are all allowed The Cursor to Argument will copy the data value of
47. screen Use the Display menu to turn the cursor display on and off 67 Plot Menu 68 TEST MENU Introduction Keypad Test CI Keyboard Test L Knob Test Ll Printer Test L Disk Drive Test More More O Keypad Test Keyboard Test The Test menu allows the user to test various features of the SR430 such as the keypad knob screen memory etc To test the data acquisi tion hardware see the Test and Calibration section of the manual TEST Keypad Test Keyboard Test Knob Test Printer Test Printer Type Disk Drive Test Screen Dump More Print String RS 232 Test Memory Test Main Memory Screen Test Peripheral Memory Video Memory Return This key activates the keypad test screen The keypad test screen dis plays a map of the keypad with each key represented by a small square Pressing each key will highlight the corresponding square When all squares are highlighted the test is complete This key activates the keyboard test screen Characters typed on an at tached PC keyboard in PC or 8088 mode will be displayed on the test screen If the displayed characters are accurate then the keyboard inter face is functioning and the keyboard is configured correctly If not check that the keyboard is in correct mode Many keyboards have a switch on the bottom to select PC 8088 or AT 80286 mode 69 Test Menu Knob Test Printer Test Printer HP EPSON Screen Dump
48. the SR430 to 9600 baud 8 bits no parity before running the program To read the data record over the RS232 interface the BINA n command is used to read points individually Binary transfer is not supported over the RS232 interface all data is transmitted in ASCII format 10 EXAMPLE PROGRAM USING BASIC AND THE COM1 SERIAL PORT 20 THIS PROGRAM ASSUMES THAT A TTL TRIGGER SOURCE IS CONNECTED TO THE TRIGGER IN PUT 30 40 OPEN COM1 9600 n 8 2 CS DS CD AS 1 50 60 WRT OUTP 0 DIRECT 59430 OUTPUT TO RS232 PORT 70 PRINT 1 WRT 80 90 WRT BREC 1 SET RECORD LENGTH TO 1024 BINS 100 PRINT 1 WRT 110 120 WRT TRLV 5 SET TRIGGER LEVEL TO 5 V 130 PRINT 1 WRT 140 150 WRT TRLV QUERY TRIGGER LEVEL 160 PRINT 1 WRT 170 INPUT 1 TL INPUT TRIGGER LEVEL 180 PRINT Trigger Level TL PRINT TRIGGER LEVEL 190 200 WRT CLRS RESET DATA MEMORY 210 PRINT 1 WRT 220 230 WRT SSCN START SCAN WITH NEXT TRIGGER 240 PRINT 1 WRT 250 260 WRT STB READ SERIAL POLL STATUS BYTE 270 PRINT 1 WRT 280 INPUT 1 SP 290 IF SP MOD 2 0 GOTO 270 WHILE SCAN IS IN PROGRESS 300 310 FOR l 1 TO 1024 STEP 1 READ 1024 DATA POINTS 320 PRINT 1 1 1 USING BINA 330 INPUT 1 BIN 340 PRINT 1 BIN 350 NEXT 360 400 STOP 97 Program Examples 98 Program Examples IBM PC Microsoft C V5 1 using the National Instruments GPIB interface To successfull
49. the cursor marker i e all data values are divided by the cursor marker data val ue The new value of the cursor marker data is 1 000 The new data will no longer be counts per bin but will simply be floating point numbers See 23 Guide To Operation the description of the MATH menu for more infor mation about floating point representations of the data Data may be restored to the original count data using the REACQUIRE function in the MODE menu NORM is useful when measuring relative quanti ties such as absorption or gain PRINT PRINT will print the currently displayed screen to a printer attached to the rear panel parallel printer port The entire screen including text and menus is printed The time and date will also be printed The printer type needs to be configured in the SETUP menu before using PRINT A PrScrn in Progress message will appear on the screen while printing is in progress No other front panel operations may be performed until printing is com pleted If no printer is attached or there is a printer error then the print operation is aborted after about 10 seconds A PrScrn Aborted message will appear briefly on the screen HELP HELP provides on screen help with any key or soft key Pressing HELP followed by any key will display information about the function or use of that key HELP with a soft key will describe the menu item next to the soft key Pressing another key will exit the h
50. the data to measure the lifetime directly Finally the data curve is printed or plotted and stored to disk INSTRUMENT CONFIGURATION Trigger Level Trigger Slope Disc Level Disc Slope Bin Clk Source Bin Width Bins Record 1k Records Scan 100 Trigger Offset 0 Accumulate Mode Add 1 000 V RISE 20 0 mV FALL Internal 20 48 us 114 Trigger threshold set to 1 000V Trigger on rising edge of LED trigger Disc threshold set to 20 0 mV Discriminate negative pulses Internal bin time base 20 48 us bins 1024 bins record Accumulate 100 records Start data at bin 0 Add all records to accumulation SR430 CIRCUIT DESCRIPTION Power Supply Board CAUTION Always disconnect the power cord and wait at least two minutes before open ing the unit Dangerous power supply voltages may be present even after the unit has been unplugged Check the LED at the front edge of the power supply board The unit is safe only if the LED is OFF If the LED is ON then DO NOT attempt any service on the unit This unit is to be serviced by qualified service personnel only There are no user serviceable parts inside 115 ECL Logic Board TTL Logic Board CIRCUIT BOARDS The SR430 has five main printed circuit boards The five boards shown above contain all of the ac tive circuitry of the unit A sixth front panel circuit board not shown only has keypad contacts print ed on it and holds no active compo
51. the front panel inac tivated To defeat this feature set the Overide Remote to Yes In this mode no GPIB remote enable will put the unit into REMOTE state If the SR430 is in the REMOTE state the HELP key re turns the unit to local front panel control Return The Return key will return to the Setup Communications menu 39 Setup Menu View Queues Return The last 256 characters received or transmitted by the SR430 may be displayed to help find programming errors The View Queues key will dis play the interface buffers as they are when the key is pressed This screen is updated regularly to display new interface activity The View Queues screen may slow down the communications between the SR430 and a host computer In general the View Queues screen should be dis played only when testing or debugging a host program The most recent data is displayed at the right of the upper line of each queue display For example in the screen below the DCLV If string was the most recently received command The If character is a line feed and is the string delimiter The most recently transmitted string is 010000 If in response to the DCLV command The earliest command received was IDN and the earliest response was Stanford Research Systems SR430 s n00001 verO07 If J Unrecognized characters are ig nored and not displayed The terminator character on the output queue is always shown as a If When the output is directed t
52. 0 msec 1 300 msec bottom 0 cnts 10 cnts Div Record 100 Return 63 Math Menu Calc Argument Type Const File Argument 234 Cursor to Arg L Operation Do Calc The Calculation sub menu allows the user perform simple arithmetic cal culations with the displayed data Operations are performed on the entire data record in display memory regardless of graph scaling Performing a calculation on the data will change the data from integer count data into single precision 16 bits floating point representation Any calculation which requires a greater range will either underflow re turn zero or overflow An operation which overflows will display an error message and abort Once converted the data remains in floating point form even when the Calculation menu is exited To convert the data back into integer count data use the ReAcquire function in the Mode menu If floating point data is saved to disk using the Save Trace function it will be recalled as floating point data using Recall Trace To avoid acciden tally losing original data save the count data to a disk file before performing Calc menu operations Argument Type Cursor to Arg Catalog On Off The Operation function selects the type of operation to be performed The add subtract multiply and divide functions require a second argu ment which may be a number or a data file The log base 10 and square root function
53. 00002 501 5 00225 548 5 00225 548 5 00100 517 5 00215 501 5 00225 548 5 00065 513 5 00065 513 5 00003 501 5 00065 513 5 00003 501 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00012 501 5 00003 501 3 00202 301 3 00203 301 3 00203 301 3 00230 301 3 00202 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00135 301 3 00004 301 1 00008 130 1 00088 130 1 00114 116 6 0001 7 630 6 00072 601 6 0001 7 630 6 0001 7 630 4 00284 421 4 00247 425 4 00283 421 4 00247 425 4 00247 425 4 00247 425 4 00283 421 4 00247 425 4 00247 425 330P 1U AXIAL 1 0U 1U AXIAL 1U AXIAL 1U AXIAL 100P 1U AXIAL 1U AXIAL 2 2U 20P 1U AXIAL 01U 01U 10P 01U 10P 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 330P 10P MSD6100 1N5711 1N5711 1N5240A MSD6100 1N4148 1N4148 1N4148 1N4148 1N5445A 1N4148 20 PIN DI 40 PIN DI 10 PIN WHITE FB43 301 O5UH V FB43 301 FB43 301 1 0KX4 100X9 47X4 100X9 100X9 100X9 47X4 100X9 100X9 134 Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Silver Mica Miniature Capacitor Silver Mica Miniature Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Mylar Poly 50V 5 Rad Cap Stacked Metal Film 50V 5 40 85c Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic Disc 50V 10 SL Capacitor Cer
54. 0023 529 32 5 00098 517 33 5 00023 529 34 5 00098 517 35 5 00023 529 MC 1488 DP8473N 74HC157 24 000 MHZ 32 768 KHZ 13 5168 MHZ 24 000 MHZ 3 6864 MHZ CLS 440 3 2 PIN JUMPER 26 COND 25 PIN IDC 129 Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Crystal Crystal Crystal Crystal Crystal Nut PEM Connector Female Cable Assembly Ribbon Connector D Sub Female DESCRIPTION Capacitor Electrolytic 35V 2096 Rad Capacitor Electrolytic 35V 2096 Rad Capacitor Electrolytic 25V 2096 Rad Capacitor Electrolytic 25V 2096 Rad Capacitor Electrolytic 10V 2096 Rad Capacitor Electrolytic 10V 2096 Rad Capacitor 6 3V Electrolytic Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 20 Z5U Capacitor Ceramic Disc 50V 20 Z5U Capacitor Ceramic Disc 50V 20 Z5U Capacitor Ceramic Disc 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Capacitor Electrolytic 50V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Electrolytic 50V 20 Rad
55. 18 402 2 2K Resistor Carbon Comp 1 2W 5 R 61 4 00618 402 2 2K Resistor Carbon Comp 1 2W 5 R 62 4 00360 401 430 Resistor Carbon Film 1 4W 5 R 63 4 00360 401 430 Resistor Carbon Film 1 4W 596 131 art Lista R 64 4 00051 401 2 7K Resistor Carbon Film 1 4W 596 R 65 4 00027 401 1 5K Resistor Carbon Film 1 4W 596 R 66 4 00076 401 390 Resistor Carbon Film 1 4W 596 R67 4 00051 401 2 7K Resistor Carbon Film 1 4W 596 R 68 4 00027 401 1 5K Resistor Carbon Film 1 4W 596 U 1 3 00143 340 LM393 Integrated Circuit Thru hole Pkg U2 3 00039 340 74HC14 Integrated Circuit Thru hole Pkg U3 3 00088 340 LF353 Integrated Circuit Thru hole Pkg U4 3 00088 340 LF353 Integrated Circuit Thru hole Pkg U5 3 00088 340 LF353 Integrated Circuit Thru hole Pkg U6 3 00088 340 LF353 Integrated Circuit Thru hole Pkg U7 3 00149 329 LM317T Voltage Reg TO 220 TAB Package U8 3 00088 340 LF353 Integrated Circuit Thru hole Pkg U9 3 0031 9 340 AD586JN Integrated Circuit Thru hole Pkg U 10 3 00114 329 7815 Voltage Reg TO 220 TAB Package U 11 3 00141 329 LM337T Voltage Reg TO 220 TAB Package U 12 3 00120 329 7915 Voltage Reg TO 220 TAB Package U 13 3 00149 329 LM317T Voltage Reg TO 220 TAB Package U 14 3 00149 329 LM317T Voltage Reg TO 220 TAB Package U 15 3 00141 329 LM337T Voltage Reg TO 220 TAB Package U 16 3 00105 340 LM741 Integrated Circuit Thru hole Pkg Z0 0 00158 000 60MM 24V Hardware Misc
56. 2 340 3 00362 340 3 00362 340 3 00356 340 3 00356 340 3 00299 341 3 00299 341 3 00046 340 3 00046 340 3 00044 340 3 00299 341 3 00299 341 3 00044 340 3 00364 340 3 00364 340 3 00364 340 3 00364 340 3 00045 340 3 00171 340 3 00171 340 3 00171 340 3 00171 340 3 00165 340 3 00342 340 3 00044 340 3 00046 340 3 00046 340 3 00046 340 3 00046 340 3 00046 340 8KX8 45 8KX8 45 8KX8 45 8KX8 45 32KX8 100L 74F157 16 000 MHZ 74AC74 74HC73 74F32 74F74 74F74 74F32 74F191 74F191 74F191 74F191 74F373 74F373 74HC244 74HCT354 74HC244 74HCT354 74HC32 74F283 74F283 74F283 74F283 74 374 74F374 32KX8 100L 32KX8 100L 74HC374 74HC374 74HC244 32KX8 100L 32KX8 100L 74HC244 74 86 74 86 74 86 74 86 74HC32 74HC191 74HC191 74HC191 74HC191 74HC08 74ALS138 74HC244 74HC374 74HC374 74HC374 74HC374 74HC374 141 STATIC RAM I C STATIC RAM I C STATIC RAM I C STATIC RAM I C STATIC RAM I C Integrated Circuit Thru hole Pkg Crystal Oscillator Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg
57. 2 menu To con nect the SR430 to a PC serial adapter which is usually a DTE use a straight thru serial cable Also a serial plotter with HPGL compatible graph ics may be connected to the RS232 port The SR430 will drive the plotter to generate plots of the screen graph Use the SETUP PLOTTER menu to configure the SR430 to use a serial plotter PARALLEL PRINTER CONNECTOR The PRINT key will print the screen to an Epson compatible graphics printer or an HP LaserJet compatible laser printer Use a standard printer cable to attach the printer to the printer port Use the SETUP PRINTER menu to choose the type of printer Guide To Operation PC KEYBOARD CONNECTOR A n IBM PC or XT compatible keyboard may be at tached to the keyboard connector An AT key board may be used if it can be switched to PC or 8088 mode Typing at the attached keyboard is the same as entering numbers and letters from the front panel keypad Highlighted parameter entry fields will accept characters from the keyboard Typing E or e is the same as EXP In general the keyboard is only useful for alphabetic fields such as file names BNC CONNECTORS INHIBIT INPUT If the INHIBIT input is TTL high when a trigger is received then that record of data is ignored and not accumulated The record will count towards the number of records per scan SUBTRACT INPUT When the accumulate mode is set to EXTERNAL records which are triggered when the SUBTRACT I
58. 25 C to 65 C Humidty lt 95 Non condensing Symbols you may find on SRS products Symbol Description ES Alternating current Caution risk of electric shock Frame chassis terminal ra Caution refer to accompanying documents Earth ground terminal o eem SR430 MULTICHANNEL SCALER AVERAGER GENERAL INFORMATION The SR430 Multichannel Scaler Averager counts incoming pulses in successive time bins A trigger starts a record of up to 32 704 time bins The duration of the time bins is programmable from 5 ns to 10 5 ms The number of signal pulses counted during each time bin is stored in memory There is no dead time between bins Each new trigger starts a record whose data is added to the bin by bin accumulation of all of the previ ous records The result is a record of the sum or average of all counts in each time bin The trigger starts each record The SYNC BUSY output signals the beginning of the first time bin of the record The BIN CLOCK output signals the boundaries of each time bin During each time bin input signal pulses are counted At the end of the time bin the counter data is stored in memory and the counter is reset The double buffered design ensures that there is no dead time between bins and no pulses are missed at the bin boundaries After the record is complete the data is added to the accumulation of all previous records This only occurs after the record of data is acquired and results
59. 301 1N5822 Diode DS1 3 0001 1 303 RED LED T1 Package F 1 4 00436 409 Resistor Wire Wound F 2 4 00436 409 Resistor Wire Wound F 3 4 00436 409 Resistor Wire Wound F 4 4 00436 409 Resistor Wire Wound J1 1 00114 116 10 PIN WHITE Header Amp MTA 156 JP1 1 00039 116 5 PIN WHITE Header Amp MTA 156 JP2 1 00116 130 4 PIN DI DISK Connector Male JP3 1 00119 116 3 PIN WHITE Header Amp MTA 156 JP4 1 00117 116 20 PIN WHITE Header Amp MTA 156 PC1 7 00262 701 002 Printed Circuit Board Q 1 3 00022 325 2N3906 Transistor TO 92 Package Q2 3 00233 329 TIP31B Voltage Reg TO 220 TAB Package Q3 3 00257 329 TIP41B Voltage Reg TO 220 TAB Package Q4 3 00258 329 TIP42 Voltage Reg TO 220 TAB Package Q5 3 00258 329 TIP42 Voltage Reg TO 220 TAB Package Q6 3 00378 329 TIP102 Voltage Reg TO 220 TAB Package Q7 3 00378 329 TIP102 Voltage Reg TO 220 TAB Package Q8 3 00257 329 TIP41B Voltage Reg TO 220 TAB Package Q9 3 00325 329 TIP107 Voltage Reg TO 220 TAB Package Q 10 3 00325 329 TIP107 Voltage Reg TO 220 TAB Package R 1 4 00084 401 5 1K Resistor Carbon Film 1 4W 5 R2 4 00063 401 3 0K Resistor Carbon Film 1 4W 5 R3 4 00045 401 2 0K Resistor Carbon Film 1 4W 5 R4 4 00372 431 50 30 25 Thermistor PTC Positive Temp Control R5 4 00081 401 470 Resistor Carbon Film 1 4W 5 R6 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 130 art 15 LUCICCILEELEIeLL ILSII CGUGAGGHUAII oe30 AOLU
60. 32 Baud Rate Setup GPIB GPIB Address Overide Remote Word Length Parity View Queues The SR430 only outputs data to one interface at a time Commands may be received over both interfaces but responses are directed only to the interface selected by the Output To key Make sure that the Output inter face is set correctly before attempting to program the SR430 from a com puter The Setup RS232 key activates the RS232 parameters sub menu Baud rate word length and parity may be configured in this sub menu 38 Setup Menu Baud Rate Baud Rate The Baud Rate key allows the knob to adjust the RS232 baud rate The baud rate can be set to any standard val Word Length ue from 300 to 19200 baud 7 bits Word Length This key toggles the character length The RS232 char acter length can be 7 or 8 bits 8 bits is standard Parity Even Parity This key toggles the parity The RS232 parity can be Odd None Even Odd or None Return The Return key will return to the Setup Communications menu Return Setup GPIB The Setup GPIB key activates the GPIB parameters sub menu GPIB in strument address and Remote Overide are set in this sub menu GPIB Address GPIB Address This key activates the GPIB Address entry field for nu meric and knob entry The instrument address can be Overide Remote set from 0 to 30 X Overide Remote In general every GPIB interface command will put the SR430 into the REMOTE state with
61. 4 U IV I LU oPDSUS L L LLL U 101 U 201 U 202 U 203 U 204 U 205 U 206 U 207 U 208 U 401 U 402 U 403 U 404 U 501 U 502 U 503 U 504 U 505 U 506 U 601 U 602 U 603 U 606 U 607 U 608 U 609 U 610 U 611 U 612 U 701 U 702 U 703 U 704 U 705 U 706 U 801 U 802 U 803 U 804 U 805 U 806 U 807 U 808 U 809 U 810 U 811 U 812 U 813 U 814 U 815 U 901 U 902 U 903 U 904 U 905 3 00354 340 3 00340 340 3 00340 340 3 00340 340 3 0034 1 340 3 0034 1 340 3 00342 340 3 00343 340 3 00344 340 3 00299 341 3 00299 341 3 00299 341 3 00299 341 3 00342 340 3 00342 340 3 00342 340 3 00049 340 3 00347 340 3 00259 340 3 00049 340 3 00348 340 3 00265 340 3 00044 340 3 00046 340 3 00044 340 3 00046 340 3 00049 340 3 00049 340 3 00039 340 3 00051 340 3 00349 340 3 00300 340 3 00263 340 3 00110 340 3 00251 340 3 00051 340 3 00171 340 3 00277 340 3 00351 340 3 00280 340 3 00049 340 3 00274 340 3 00303 340 3 00351 340 3 00598 340 3 00046 340 3 00046 340 3 00299 341 3 00299 341 3 00262 340 3 00350 340 3 00645 340 3 00078 340 3 00079 340 3 00247 340 80C186 12 74ALS373 74ALS373 74ALS373 74ALS245 74ALS245 74ALS138 74ALS32 74ALS08 32KX8 100L 32KX8 100L 32KX8 100L 32KX8 100L 74ALS138 74ALS138 74ALS138 74HC74 74LS148 74HCT373 74HC74 74HC20 74HC595 74HC244 74HC374 74HC244 74HC374 74HC74 74HC74 74HC14 74HCU04 MC146818P 74LS374 DS75451N MC1489 74C04 74HCU04 74HC191 74HC11 74H
62. 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 art 15 EEEEERERLLLLUILIIILIIUIILIIIIULULIUUIIL UIILI cLTLTIILLAE IPeG CH SGAGIDGI GOIILLLLLU0 1 DI AEHLALILLILL U 801 U 802 U 803 U 804 U 805 U 806 U 901 U 902 U 903 U 904 U 905 U 906 U 907 U 908 U 909 U 910 U 911 U 912 U 913 U 1001 U 1002 U 1003 U 1004 U 1005 U 1006 U 1007 U 1008 U 1009 U 1010 U 1011 U 1012 U 1013 U 1014 U 1015 U 1016 U 1017 U 1018 U 1019 U 1020 U 1021 U 1022 U 1023 U 1101 U 1103 U 1104 U 1105 U 1106 U 1107 U 1201 U 1301 U 1302 U 1303 U 1304 U 1305 U 1306 3 00367 341 3 00367 341 3 00367 341 3 00367 341 3 00299 341 3 00365 340 6 00073 621 3 00274 340 3 00048 340 3 00360 340 3 00238 340 3 00238 340 3 00360 340 3 00207 340 3 00207 340 3 00207 340 3 00207 340 3 00361 340 3 00361 340 3 00044 340 3 00363 340 3 00044 340 3 00363 340 3 00045 340 3 00362 340 3 0036
63. 611 20 0 00014 002 20 0 00043 011 20 0 00048 011 20 0 00079 031 20 0 00084 032 20 0 00089 033 20 0 00098 042 20 0 00113 053 20 0 00116 050 20 0 00120 050 20 0 00123 053 20 0 00124 053 20 0 00126 053 20 0 00136 053 20 0 00149 020 20 0 00168 023 20 0 00187 021 20 0 00190 030 20 0 00210 020 20 0 00212 021 20 0 00241 021 20 0 00248 026 20 0 00256 043 20 0 00257 000 20 0 00259 021 20 0 00287 053 20 0 00310 010 20 0 00318 004 20 0 00320 004 20 0 00330 050 20 0 00331 031 20 0 00335 000 20 0 00336 027 20 0 00337 027 20 0 00338 023 20 0 00339 042 20 0 00340 016 20 0 00343 027 20 0 00368 053 20 0 00369 053 20 0 00394 031 74HC74 74HC74 74HC04 AD7542JN LF347 DG211 VALUE 1A 3AG 6J4 4 40 KEP 6 32 KEP 4 40X3 16 M F 36154 4 6 LOCK 10 24 11 3 4 18 16 18 21 24 22 1 2 24 3 1 2 24 8 1 2 24 4 40X1 4PF 6 32X5 16R 4 40X1 4PP 8X1 4 40X5 16PF 6 32X2PP 4 40X3 16PP 10 32X3 8TRUSSP 6 SHOULDER HANDLES 4 40X1 2 PP 8 5 24 GRN HEX 3 8 32 SR430 SR430 CAP 5 1 2 18 4 40X5 8 F F FAN GUARD 2 4X1 4PP B 4X3 8PP B 2 56X1 4RP 2 LOCK F0204 4X1 4PF B 21 24 21 24 6 32X13 16 HARDWARE M 142 Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg DESCRIPTION Fuse Power_Entry Hardware Nut Kep Nut Kep Standoff
64. 7 503 5 00100 517 6 0021 2 630 6 00213 630 7 00282 720 ELLE REF SRS part C 1 5 00100 517 C2 5 00225 548 C3 5 00225 548 C 4 5 00225 548 C 5 5 00225 548 C6 5 00225 548 C7 5 00225 548 C8 5 00225 548 C9 5 00225 548 MC10H102 MC10H131 MC10H125 74F74 74F191 74HCT191 74HCT191 74 374 74HCT374 MC10H107 MC10H131 MC10H131 MC10H131 MC10H141 MC10H141 MC10H141 MC10H141 MC10H125 MC10H125 MC10H125 MC10H125 74F374 74F374 MC10124 MC10124 MC10124 3 e 4 2 1 4 24 TO 5 TO 18 SOLDR SLV RG174 INSL 01U 2 2U 1 X 25 CYL 2 HOLE SR430 22 VALUE 2 2U 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL TTLLOGIC BOARD ME 138 Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Lugs Tie Wire 24 UL1007 Strip 1 4x1 4 Tin Heat Sinks Insulators Termination Connector BNC Capacitor Ceramic Disc 50V 2096 Z5U Capacitor Tantalum 35V 2096 Rad Ferrite Beads Ferrite Beads Fabricated Part Thru hole Pkg Thru
65. 8 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 19 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 20 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 21 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX 22 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 23 5 00225 548 AXIAL Capacitor Ceramic 50 80 20 250 AX 24 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 C 25 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 26 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 27 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 C 28 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 29 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 30 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 31 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 32 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 33 5 00225 548 AXIAL Capacitor Ceramic 50 80 20 250 AX 34 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 35 5 00225 548 AXIAL Capacitor Ceramic 50 80 20 250 AX C 36 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 250 AX C 37 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 38 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 39 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 40 5 00100 517 2 2U
66. 8 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 1005 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad C 1006 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1007 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1008 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1009 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C1010 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1011 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C1012 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C1013 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 1014 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 1015 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 125 art 15 LxELOITILCLqCKlCKLLLLLULXTO PRUheur4 9 9 9 9 kKR ARLLGS LE C 1016 C 1017 C 1018 C 1019 C 1020 C 1021 C 1022 C 1023 C 1024 C 1025 C 1026 C 1027 C 1028 C 1029 C 1030 C 1031 C 1032 C 1033 C 1034 C 1035 C 1036 C 1037 C 1038 C 1039 C 1040 C 1041 C 1042 C 1043 C 1044 D 401 D 601 D 602 D 603 D 604 D 605 D 606 D 607 D 608 D 701 D 702 D 703 D 704 D 705 JP201 JP301 JP302 JP303 JP601 JP602 JP603 JP701 JP702 JP801 JP802 JP803 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00100 517 5 00225 548 5 00225 548 5 00100 517 5 00225 548 5 00225 548 5 00225 548 5 00225 54
67. 8 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00100 517 5 00225 548 5 00225 548 5 00225 548 5 00100 517 5 00225 548 5 00225 548 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00203 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 1 00109 130 1 00042 130 1 00008 130 1 00109 130 1 00113 100 1 00207 133 1 00109 130 1 00006 130 1 00083 130 1 00035 130 1 00109 130 1 00086 130 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 2 2U 1U AXIAL 1U AXIAL 2 2U 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 2 2U 1U AXIAL 1U AXIAL 1U AXIAL 2 2U 1U AXIAL 1U AXIAL 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N5711 1N4148 1N4148 1N4148 1N4148 4 PIN DI 8 PIN DI 20 PIN DI 4 PIN DI DIN 5 30 PIN DRA 4 PIN DI 2 PIN DI 26 PIN DIL 20 PIN DIL 4 PIN DI 3 PIN SI 126 Capacitor Ceramic 50V 80 20 ZBU AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Tantalum 35V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Tantal
68. BUF I 580 NEXT I 590 600 STOP 1000 PRINT CANNOT FIND DEVICE MCS 1010 STOP 102 TEST AND CALIBRATION POWER To start make sure that the power entry module on the rear panel is set for the ac line voltage in your area and that the correct fuse is installed The selected ac voltage may be seen through the window on the power entry module Verify that the line cord is plugged all the way into the power en try module and that the power button on the front panel is pressed in SCREEN BRIGHTNESS If the screen is too dark or too bright adjust the brightness using the knob at the upper left of the screen Do not set the brightness higher than nec essary DISPLAY POSITION Use the Setup Screen function in the SETUP menu to position the display in the center of the screen FAN The fan in the SR430 is temperature controlled When the unit is cold the fan is at half speed When the internal temperature reaches about 30 C the fan speed increases Do not block the vents in the chassis or the unit may not operate properly FRONT PANEL TESTS The keypad knob disk drive screen and memory may be tested using the Test menu See the Test menu section for a complete description of the tests POWER ON RESET If the instrument turns on with odd settings an in correct or blank screen display or is unresponsive to the keypad or knob then the memory contents may have been corrupted causing the instrument to han
69. CT299 74HC10 74HC74 74AC74 74HC164 74HCT299 63484P 98 74HC374 74HC374 32KX8 100L 32KX8 100L 74HC86 74ALS04 NAT9914APD DS75160A DS75161A SCN2641 Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg ntegrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg STATIC RAM I C STATIC RAM I C STATIC RAM I C STATIC RAM I C Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit STATIC RAM I C STATIC RAM I C Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg ann ON Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg
70. Capacitor Tantalum 35V 20 Rad C 41 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX 42 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 43 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 44 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 45 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 46 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 47 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 48 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 49 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 50 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 51 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 52 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 53 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 54 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 250 AX C 55 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 56 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 57 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 58 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 59 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad 60 5 00100 517 2 20 Capacitor Tantalum 35V 20 Rad C 61 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 62 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 63 5 00225 548
71. FAST AND PRETTY GOOD WAY This technique works very well and is particularly suited for those who do not want to make a career out of plateauing their PMT s The PMT should be operated at or a bit above the recommended maximum high voltage Provide enough illumina tion for a count rate of a few megahertz and enough preamp gain to get pulse heights of about 100 mV Using a 300 MHz oscilloscope adjust the snubber termination impedance for the best pulse shape Look carefully at the anode pulse shape and set the discriminator to a level which is above any ringing but well below the mean pulse height If there is lots of EMI or amplifier noise then in crease the PMT s high voltage to increase the sig nal pulse height Using Photomultiplier Tubes 112 TYPICAL EXPERIMENT This experiment is typical of many time resolved photon counting experiments A pulsed light source is used to pump atoms to an excited state Fluorescent decay from the excited state are ob served allowing the lifetime of the state to be measured ENERGY LEVELS OF RUBY The energy level diagram of Ruby is shown below There are absorption bands around 400 nm and 550 nm The Cr ions which absorb light at these wavelengths decay in about 50 ns to the upper state of the well known laser transition This state has a lifetime of about 3 5 ms and decays to the ground state by emitting a photon at 694 3 nm The absorption band at 550 nm overlaps the emis ABSO
72. GENERAL Interfaces Hardcopy Disk Power Dimensions Weight Warranty SR430 Multichannel Scaler Output current rating 10mA Output impedance lt 1 Accuracy 0 196 10 mV Analog 50 input 10 k input TTL input Rising edge triggers next time bin TTL input sampled each trigger If high causes the current record to be ignored not accumulated TTL input sampled each trigger If high causes the current record to be subtracted from the accumulation in external toggle mode IEEE 488 RS 232 and Centronics Printer standard All instrument functions can be controlled and read through the IEEE 488 and RS 232 interfaces Screen dumps to Epson compatible dot matrix or HP LaserJet print ers parallel Plots to HPGL compatible plotters serial or IEEE 488 3 5 MSDOS compatible format 720kbyte capacity Storage of data and setups 60 Watts 100 120 220 240 VAC 50 60 Hz 17 W X 6 25 H X 16 5 L 30 Ibs One year parts and labor on materials and workmanship SR430 Multichannel Scaler SR430 Quick Performance Check Be sure to read the Overview and Operations sections of the manual to familiarize yourself with the instru ment This setup requires a 1 Hz to 2 kHz TTL trigger source A simple function generator will suffice Hold down the CLR key while turning the unit on This resets the SR430 to its default state Connect the trigger source to the TRIGGER input on the front panel Set the Trigger Level and Slope in the
73. I C Hardware Misc Hardware Misc Hardware Misc Screw Panhead Phillips Hardware Misc Screw Truss Phillips Screw Black All Types Screw Panhead Phillips Screw Panhead Phillips Fabricated Part Fabricated Part Fabricated Part 1290 D Reamwood Avenue Sunnyvale CA 94089 Phone 408 744 9040 FAX 408 744 9049 email info thinkSRS com Web www thinkSRS com R Stanford Research Systems Addendum RE Disk Utilities of the SR430 Date Sept 10 2002 Some of the SRS instruments have build in floppy disk drives The SR430 only works properly with low density disks DS DD Recently it has become increasing difficult to find low density disks DS DD However there is a quick and easy way to convert a high density disk to a low density one Just follow the procedure below 1 Orient the high density disk so that the label side is facing up and the metal slider is facing down Notice there are two small rectangular holes on the top of the floppy disk 2 Useasingle piece of sturdy tape must be opaque to cover both sides of the hole at the upper left corner of the floppy disk Be sure to stretch the tape tightly so that it will not sag 3 Format the disk in one of the above mentioned instruments 145
74. M x commands translate the graph vertically to make the Y value corresponding to the bottom of the graph equal to i or x The parameter i is used when the graph displays integer count data The value of i may range from 32767 to 32767 The parameter x is used when the graph displays floating point data The value of x is rounded to the nearest 1 10 of a division Values of x which translate the data far off screen may be limited to a maximum or mini mum value depending upon the range of the data The HSCL command sets or reads the horizontal screen width The pa rameter i selects a screen width below The screen width may not be set such that the screen width plus the left most bin exceeds the number of bins per record i e the graph may not be scaled to display a bin which is beyond the end of the record Unlike horizontal scaling from the front panel which takes place about the cursor position the HSCL command leaves the left most bin fixed while changing the screen width 83 Remote Programming VSCL i x CURS 2 i CURW 2 i CURM i GRID 7 i SETUP COMMANDS i screen width in bins i screen width in bins 0 8 12 6k 1 16 13 7k 2 32 14 8k 3 64 15 9k 4 128 16 10k 5 256 17 11k 6 512 18 12k 7 1k 19 13k 8 2k 20 14k 9 3k 21 15k 10 4k 22 16k 11 5k The VSCL command sets or reads the vertical scale Unlike vertical scal ing from the front panel which takes place about the center of the screen the VSCL
75. NPUT is TTL high are subtracted from the accu mulation This input is sampled at the trigger to de termine what to do with the ensuing data record TOGGLE OUT The TOGGLE OUT is a TTL signal which indicates 26 what the accumulation mode of the next record will be This output is only used if the accumulation mode is set to TOGGLE TOGGLE switches at the end of the SYNC BUSY time to reflect the accu mulation mode of the next trigger If TOGGLE is high then the next record will be subtracted The state of TOGGLE at the time of the trigger deter mines the accumulation mode of the data record TEST TEST is a 50 NIM level output The output fre quency is 50 MHz and is synchronous with the BIN CLK The TEST signal is used to test the counter and accumulator by putting a known num ber of counts into each bin See the Test and Troubleshooting section for further information AUX 1 and AUX 2 The AUX outputs are general purpose program mable dc analog outputs The output voltages may be set from the LEVELS menu The output range is 10V to 10V and the maximum current output is 10 mA LEVELS MENU Introduction The Levels menu is used to set the trigger and discriminator settings as well as the Aux output levels Trigger Level Pressing the Trigger Level key selects the trigger threshold level as the active entry field A new trigger level may be entered from the numeric keypad in units of Volts or the kno
76. Ohm systems are usually used The current pulse from the PMT travels down a 50 Ohm cable which is terminated by the 50 Ohm input impedance of a preamplifier The at tenuation of RG 58 coax cable at 300 MHz is about 1 dB 10 ft and so it does not significantly degrade performance in this application To allow counting to 200 MHz a preamplifier with a bandwidth which is somewhat larger than 200 MHz is required The SR440 preamplifier has four gain of 5 amplifiers each with 50 Ohm input impe dance and a 300 MHz bandwidth The amplifiers may be cascaded for gains of 5 25 125 or 625 GAIN REQUIREMENT The SR430 can detect pulses as low as 2 mV To allow for some adjustment of the discriminator threshold and to provide better noise immunity a more practical lower limit on pulse size is about 10 mV The highest discriminator level which may be set is 300 mV The preamplifier should have enough gain to amplify anode pulses to between 10 mV and 300 mV 100 mV is a good target val ue Using the result that pulse height in mV is about 4x the tube gain in millions divided by the rise time in ns a PMT with a gain of 4 million and a risetime of 2 ns will provide 8 mVoutput pulses Half of the pulse amplitude will be lost in the anode snubber so a gain of 25 is required to boost the output pulses to 100 mV amplitude PLATEAUING A PMT Due to the statistical nature of the secondary emis sion process there is a distribution
77. Q 304 R 101 R 102 R 103 R 104 R 105 R 106 R 107 R 108 R 109 R 110 R111 R112 113 114 115 116 117 118 119 120 R 121 R 122 R 206 R 207 R 208 R 209 R 210 R 211 R 212 4 00247 425 4 00247 425 4 00247 425 4 00422 421 4 00247 425 4 00247 425 4 00247 425 4 00247 425 4 00247 425 4 00247 425 4 00247 425 4 00247 425 4 00326 441 7 00267 701 3 0001 8 324 3 001 78 327 3 00022 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 3 00027 325 4 00374 407 4 00347 407 4 00347 407 4 00348 407 4 00088 401 4 00079 401 4 00322 407 4 00327 407 4 00021 401 4 00322 407 4 00358 402 4 00030 401 4 00021 401 4 00021 401 4 00188 407 4 00134 407 4 00350 407 4 00351 407 4 00050 401 4 00021 401 4 00030 401 4 00030 401 4 00034 401 4 00063 401 4 00080 401 4 00080 401 4 00030 401 4 00030 401 4 00027 401 100X9 100X9 100X9 82X5 100X9 100X9 100X9 100X9 100X9 100X9 100X9 100X9 200 SR430 ECL MRF904 MRF965 2N3906 2N5770 2N5770 2N5770 2N5770 2N5770 2N5770 2N5770 2N5770 2N5770 51 1 7 50K 7 50K 2 21K 51K 4 7K 316 47 5 1 0K 316 510 10 1 0K 1 0K 4 99K 1 24K Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Res Network SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common
78. R 808 R 809 R 901 R 904 R 905 R 911 R912 R 913 S0101 S0301 S0302 S0303 S0304 1 00209 133 1 00238 161 1 00016 160 1 00088 130 1 00088 130 1 00039 116 4 00587 425 4 00334 425 4 00334 425 4 00227 425 4 00270 425 4 00334 425 4 00221 425 4 00244 421 7 00240 701 3 00026 325 3 00022 325 3 00021 325 3 00021 325 3 00022 325 4 00034 401 4 00079 401 4 00034 401 4 00034 401 4 00034 401 4 00088 401 4 00021 401 4 00034 401 4 00034 401 4 00034 401 4 00034 401 4 00063 401 4 00035 401 4 00054 401 4 00080 401 4 00080 401 4 00021 401 4 00089 401 4 00079 401 4 00031 401 4 00022 401 4 00062 401 4 00060 401 4 00081 401 4 00273 401 4 00090 401 4 00090 401 4 00022 401 4 00062 401 4 00021 401 1 00108 150 1 00026 150 1 00026 150 1 00026 150 1 00026 150 34 PIN DRA GPIB SHIELDED RS232 25 PIN D 40 PIN DI 40 PIN DI 5 PIN WHITE 10KX7 10KX5 10KX5 22KX9 1 0KX5 10KX5 150X5 10KX4 001 2N5210 2N3906 2N3904 2N3904 2N3906 10K 4 7K 10K 10K 10K 51K 1 0K 10K 10K 10K 10K 3 0K 1 0K PLCC 68 TH 28 PIN 600 MIL 28 PIN 600 MIL 28 PIN 600 MIL 28 PIN 600 MIL 127 Connector Male Right Angle Connector IEEE488 Reverse R A Female Connector D Sub Right Angle PC Female Connector Male Connector Male Header Amp MTA 156 Resistor Network SIP 1 4W 2 Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Networ
79. RPTION BAND 50 NS DECAY UPPER LEVEL OF GREEN LASER TRANSITION LED SPONTANEOUS DECAY AT 694 3 NM WITH 3 5 MS LIFETIME GROUND STATE ENERGY LEVELS FOR RUBY sion line of a green LED In this demonstration ex periment a pulsed green LED is used to quickly populate the excited state and decays from the excited state are seen through a bandpass inter 694 3 NM BANDPASS INTERFERENCE FILTER RUBY DISK GREEN LED R928 PMT ference filter centered on Ruby s 694 3 nm emis Sion line APPARATUS The apparatus is shown below The green LED is glued to the edge of a 1 cm diameter 3 mm thick ruby disk The ruby disk is viewed through the bandpass interference filter by a Hamamatsu R928 PMT This side on PMT was selected for its high gain fast rise time and good red sensitivity The phototube base uses a tapered voltage divid er with about 3x the normal interstage voltage be tween the photocathode and the first dynode This helps to narrow the pulse height spectrum for sin gle photon events The lower dynodes are by passed and 100 Ohm resisters are used between the dynodes and their bypass capacitors to reduce ringing in the anode signal A snubber network consisting of a 10 inch piece of RG174 terminated into 20 Ohms is used to further reduce anode ring ing and reduce the falltime of the output current pulse OPERATION The PMT is operated at the maximum rated high voltage 1250 Vdc The output pulses ha
80. TRAP 120 CALL IBINIT2 IBGTS IBCAC IBWAIT IBPOKE IBWRT IBWRTA IBCMD IBCMDA IBRD IBRDA IBSTOP IBRPP IBRSP IBDIAG IBXTRC IBRDI IBWRTI IBRDIA IBWRTIA IBSTA IBERR IBCNT 130 140 DONE WITH DECL BAS 150 160 OUR PROGRAM STARTS HERE 170 BDNAME MCS 180 CALL IBFIND BDNAME SR430 FIND SR430 190 IF SR430 lt 0 GOTO 1000 200 210 WRT OUTP 1 DIRECT SR430 OUTPUT TO GPIB INTERFACE 220 CALL IBWRT SR430 WRT 230 240 WRT BREC 1 SET RECORD LENGTH TO 1024 BINS 250 CALL IBWRT SR430 WRT 260 270 WRT TRLV 5 SET TRIGGER LEVEL TO 5 VOLTS 280 CALL IBWRT SR430 WRT 290 300 WRT TRLV QUERY TRIGGER LEVEL 320 CALL IBWRT SR430 WRT 330 350 S SPACE 20 PRINT TRIGGER LEVEL RESPONSE 360 CALL IBRD SR430 S 370 PRINT Trigger Level S 380 390 WRT CLRS CLEAR DATA MEMORY FOR NEW SCAN 400 CALL IBWRT SR430 WRT 410 420 WRT SSCN START SCAN WITH NEXT TRIGGER 430 CALL IBWRT SR430 WRT 440 450 CALL IBRSP SR430 SP CHECK STATUS USING SERIAL POLL 460 IF SP MOD 2 0 GOTO 450 WHILE SCAN IS IN PROGRESS 470 480 WRT BINB 490 CNT 2048 500 DIM BUF 2000 101 Program Examples 510 520 CALL IBWRT SR430 WRT SEND BINB COMMAND TO BINARY DUMP THE DATA 530 540 CALL IBRDI SR430 BUF 0 CNT READ 2048 BYTES INTO INTEGER ARRAY BUF 550 560 FOR l 1 TO 1024 STEP 1 PRINT DATA RECORD TO SCREEN 570 PRINT I
81. TRLV x command sets the trigger level to x Volts where 2 000 lt x lt 2 000 The resolution is 001V The TRLV command queries the trigger level The response is a floating point value TRSL i The TRSL command selects the trigger slope The parameter i 0 selects positive or rising slope while i21 selects negative or falling slope DCLV xj The DCLV command sets or reads the discriminator threshold level The DCLV x command sets the discriminator level to x Volts where 0 300 lt x lt 0 300 The resolution is 0 0002V 0 2 mV The DCLV command quer ies the discriminator level The response is a floating point value DCSL i The DCSL command selects the discriminator slope The parameter i 0 selects positive or rising slope while i 1 selects negative or falling slope AUX1 x The AUX1 command sets or reads the AUX 1 output level The AUX1 x command sets the output level to x Volts where 10 000 lt x lt 10 000 The resolution is 0 005V 5 mV The AUX1 command queries the out put level The response is a floating point value AUX2 x The AUX2 command sets or reads the AUX 2 output level The AUX2 x command sets the output level to x Volts where 10 000 lt x lt 10 000 The resolution is 0 005V 5 mV The AUX2 command queries the out put level The response is a floating point value 81 Remote Programming MODE CONTROL COMMANDS The parameters in the Mode menu are not adjustable unless the uni
82. Termination Tie Washer lock Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Screw Flathead Phillips Screw Roundhead Phillips Screw Panhead Phillips Spacer Screw Flathead Phillips Screw Panhead Phillips Screw Panhead Phillips Screw Black All Types Washer nylon Hardware Misc Screw Panhead Phillips Wire 24 UL1007 Strip 1 4x1 4 Tin Nut Hex Knobs Knobs Wire 18 UL1007 Stripped 3 8x3 8 No Tin Standoff Hardware Misc Screw Sheet Metal Screw Sheet Metal Screw Roundhead Phillips Washer lock Power Button Screw Sheet Metal Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Standoff art 15 EEEEEEREILLL QUULUIUIILUIIIULLLLIIUIILULIGLES LCELLDS L SULULY LLU LUJUCOULLLLEAA ALAA ULULLUiL LILLOLOOAGOOOOIOOIO 0 00415 031 0 00416 020 0 00418 000 0 00443 000 0 00466 050 0 00467 050 0 00500 000 0 00521 048 0 00527 050 0 00893 026 1 00002 113 1 00003 120 1 00033 113 1 00073 120 1 00076 171 1 00110 130 1 00118 113 1 00120 113 1 00121 131 1 00128 171 1 00131 171 1 00132 171 1 00133 171 1 00134 171 1 00138 130 1 00141 171 1 00183 171 1 00193 131 2 00023 218 2 00034 220 2 00035 222 4 00649 455 4 0068 1 436 6 00059 610 6 00076 600 6 00213 630 7 00124 720 7 00254
83. USY is only output during actual data ac quisition Triggers that arrive when the unit is not acquiring data will not cause a SYNC BUSY out put BIN CLOCK OUTPUT The front panel BIN CLK output is a 50 NIM lev el signal showing the bin boundaries The first is the time period when the BIN CLK is first low following a trigger Each rising and falling transition of the BIN CLK marks the boundary of a bin Thus the second bin To is when BIN CLK is next high T3 is when BIN CLK is low again etc The first bin starts synchronously with the SYNC BUSY output BIN CLK may be used with the DISC OUT signal to determine the exact timing of the counts with respect to the time bins BIN CLK is only output during actual data acquisi tion Triggers that arrive when the unit is not ac quiring data will not cause a BIN CLK output EXT BIN CLK INPUT The front panel EXT BIN CLK input is a TTL input which allows an external source to determine the bin boundaries When the bin width mode is pro grammed to EXTERNAL the EXT BIN CLK will clock the bins After a trigger the first rising edge of the EXT BIN CLK will start the first bin SYNC BUSY goes high at the same time Each new ris ing edge of the EXT BIN CLK will clock the start of a new bin The maximum external clock rate is 4 MHz or a 250 ns minimum external bin width The EXT BIN CLK is useful if bins longer than 10 5 ms are required or when the bins must be synchro
84. User Manual SR430 Multichannel Scaler Averager RS Stanford Research Systems Revision 1 6 6 2013 Certification Stanford Research Systems certifies that this product met its published specifications at the time of shipment Warranty This Stanford Research Systems product is warranted against defects in materials and workmanship for a period of one 1 year from the date of shipment Service For warranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this document is subject to change without notice Copyright Stanford Research Systems Inc 1999 2005 2013 All rights reserved Stanford Research Systems Inc 1290 C Reamwood Avenue Sunnyvale California 94089 Phone 408 744 9040 Fax 408 744 9049 www thinkSRS com Printed in U S A ASRS TABLE OF CONTENTS CONDENSED INFORMATION Safety and Preparation for Use Symbols Specifications Quick Performance Check Abridged Command List INSTRUMENT OVERVIEW SR430 Overview Trigger and Sync Busy Bin Clock Output Ext Bin Clk Input Signal Input and Discriminator Timing Data Acquisition Add Subtract Toggle and Inhibit Aux Test Disk and Interfaces OPERATION Front Panel Overview Power Video Display Soft Keys Keypad Spin Knob Disk Drive BNC Connectors Screen
85. a time When data is re quired for the display the 16 bits of data are 117 Circuit Description latched into U804 and U809 which are parallel to serial converters The video data is then shifted out at 13 5 MHz and synchronized by U806B U803C blanks the video data except during active display times Memory is accessed twice during each display cy cle The first access reads the 16 bits of video data for the current display cycle The second ac cess is used by the controller for drawing purpos es During the drawing access data at any ad dress may be read or written This allows drawing to take place as fast as possible Commands and data are sent from the 80C186 to the HD63484 using a DMA channel This allows the HD63484 to process commands without hav ing to wait for the 80C186 to send them DISK CONTROLLER U907 is a DP8473 disk controller which integrates all of the functions of the PC interface into a single IC All motor controls read and write signals and data are all controlled by the DP8473 A DMA channel is used to send and receive data from the controller in order to satisfy the disk drive timing GPIB INTERFACE The GPIB IEEE 488 interface is provided by U902 a TMS9914A controller U903 and U904 buffer data I O to the GPIB connector U902 is pro grammed to provide an interrupt to the processor whenever there is bus activity addressed to the unit RS232 INTERFACE The SCN2641 UART U905 provides al
86. al value i 0 255 MCSS i Query the value of the MCS Status Byte If i is included only bit i is queried 10 INSTRUMENT OVERVIEW SR430 OVERVIEW The SR430 data acquisition timing is diagrammed below A trigger starts a record of up to 32 704 time bins T4 T2 TN Each time bin is of equal duration and is programmable from 5 ns to 10 ms There is no dead time between time bins During each time bin signal pulses are counted At the end of each time bin the counter data is stored in memory The memory address is then increment ed and the counter is reset for the next time bin Thus a record is a list of counter data points cor responding to counts received in successive time bins Counts which arrive at a bin boundary are not missed but either fall in the bin just ending or in the bin just starting The number of bins per record is set in 1k incre ments from 1k 1024 to 16k 16 384 This repre sents the maximum number of bins which can be displayed and analyzed at one time This limitation is due to the data display buffer having a maxi mum capacity of 16k data points The data acqui sition memory however can store up to 32k data points Up to 32 704 bins may actually be acquired and accumulated of which up to 16k bins may be displayed at a time The Trigger Offset determines how many bins are skipped at the beginning of the total record before data is transferred to the dis play buffer The maximum count ra
87. amic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Tantalum 35V 20 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Mylar Poly 50V 5 Rad Capacitor Mylar Poly 50V 5 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Mylar Poly 50V 5 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Connector Male Connector Male Header Amp MTA 156 Ferrite Beads Inductor Ferrite Beads Ferrite Beads Res Network SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Res Network SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Res Network SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Poari 15 EEEEEERERLLLLU LUIIIIUIILUIGIULLLILIUILIUILISILLILOILLIUeI LELTIL GLI EUoIILLOOOGgG h itkLUU1L L lCV LLLUtU LILUL N 402 N 403 N 404 N 405 N 501 N 601 N 701 N 702 N 703 N 704 N 705 N 1501 P 101 PC1 Q 101 Q 102 Q 103 Q 201 Q 202 Q 203 Q 204 Q 205 Q 301 Q 302 Q 303
88. ammed from 0 lt i lt 65535 When set to 0 ac cumulation will continue indefinitely Changing the records per scan dur ing data acquisition is allowed If the new value exceeds the current record number then the scan will continue until the new number of records has been acquired If the new value is lower than the current record number the scan will end after the next accumulation BOFF i The BOFF command sets or reads the trigger offset The trigger offset may be programmed from 0 to 16320 in increments of 16 The value of i is rounded to the nearest multiple of 16 The BOFF query responds with the integer i ACMD i The ACMD command sets or reads the accumulate mode The parame ter i 0 selects add i 1 selects toggle i 2 selects external TCNT i The TCNT command sets or reads the toggle count The toggle count may be programmed from 1 x i 316384 PTOG i The PTOG command sets or reads the pause at toggle state If the pa rameter i20 pause at toggle is not selected If i21 pause at toggle is selected 82 REAC ROFF i Remote Programming The REAC command performs the ReAcquire function The display buf fer is restored with original count data from the data acquisition memory Reacquire will only function when the SR430 is in the DONE state The ROFF command sets or reads the ReAcquire From Offset value The parameter i programs the offset from 0 to the trigger offset in incre ments of 16 bi
89. and if i21 the grid is on 84 SETUP COMMANDS OUTP i KCLK i ALRM i THRS i TMIN i TSEC i DMTH i DDAY i DYRS i PLTM i PLTB i PLTA i PLTS i PNTR i PNGD i PNAP i Remote Programming The OUTP command sets the output interface to RS232 i20 GPIB i21 The OUTP i command should be sent before any query commands to direct the responses to the interface in use The KCLK command sets or reads the key click on i21 or off i20 state The ALRM command sets or reads the alarm on i21 or off i20 state The THRS command sets or reads the hours setting of the clock The value of i is the range 0 x i x23 The TMIN command sets or reads the minutes setting of the clock The value of i is in the range 0 x i x59 The TSEC command sets or reads the seconds setting of the clock The value of i is in the range 0 x i x59 The DMTH command sets or reads the months setting of the calendar The value of i is in the range 1 x i lt 12 The DDAY command sets or reads the days setting of the calendar The value of i is in the range 1 lt i x31 The DYRS command sets or reads the years setting of the calendar The value of i is in the range 0 x i x99 The PLTM command sets or reads the plotter mode If i 0 plotting is di rected to the RS232 interface if i 1 plotting is to the GPIB interface The PLTB c
90. and the verti cal coordinate is y in counts Line Fit y a be t to to horizontal offset in bins and time units a vertical offset in number of counts b slope in counts bin and counts second Exp Fit y ae t0 b to horizontal offset in bins and time units a amplitude in counts b time constant in bins and time units c vertical offset in counts Gauss Fit y ae At b c whereAt t b to peak center position in bins and time units a amplitude in counts b line width in bins and time units vertical offset in counts The Left and Right Limit functions set the left and right limits of the fit re gion The default positions of the limits are the the left and right edges of the graph To move a limit move the cursor using the knob or PEAK 62 Return Limit Markers Math Menu key to the desired location of the limit Pressing the Left or Right Limit key will set the limit to the cursor position The Limits are set each time a limit key is pressed The limits are displayed as heavy dashed vertical lines as shown below The Return key will return to the main Math menu Any displayed fit will be removed and the graph restored Re entering the Fit menu and using the View Parameters function will re display the most recent fit Type of Fit Exp Gauss ES 15 LLL bin 110 1 126 msec Left 1 lh uU Limit HII Tr bin 0 bin 127
91. andard on the SR430 Any EPSON compatible dot matrix graphics printer or HP LaserJet printer may be used Full screen printouts may be generated by pressing the PRINT key on the front panel KEYBOARD An IBM PC compatible keyboard may connected to the keyboard connector The keyboard must op erate in the PC or XT mode This is often called the 8088 mode The keyboard may be used to en ter data instead of the keypad This is most useful with disk file names GUIDE TO OPERATION Power Button Video Display POWER BUTTON The SR430 is turned on by pushing in the POWER button The video display may take a few seconds to warm up and become visible Adjust the bright ness until the screen is easily readable The model firmware version and serial number of the unit will be displayed briefly when the power is turned on The memory status is also displayed All instru ment settings are stored in nonvolatile memory and are retained when the power is turned off If the memory check passes then the instrument re turns to the settings in effect when the power was last turned off If there is a memory error then the stored settings are lost and the default settings are used To reset the unit into the default state hold down the CLR key while the power is turned on The default setup is listed in a later chapter VIDEO DISPLAY The monochrome video display is the user inter face for data display and front panel programming o
92. ay from signal input to discriminator out put TRIGGER INPUT Impedance 10 k Threshold 2 000 V to 2 000 V in 1 mV steps Slope Rising or Falling SR430 Multichannel Scaler Protection INTERNAL TIME BINS Bin width Accuracy Jitter rms Indeterminacy Insertion delay EXTERNALLY CLOCKED TIME BINS EXT BIN CLK Input Maximum frequency Minimum pulse width high Minimum pulse width low Insertion delay COUNTERS ACCUMULATION Bins per record Maximum count rate Maximum count Records per accumulation Maximum accumulation Add Subtract TRIGGER RATE Minimum period between triggers OUTPUTS DISC SYNC BUSY BIN CLK OUTPUT TOGGLE TEST AUX1 AUX2 15 VDC 100 V for 1 us 5 ns 40 ns 80 ns 160 ns 320 ns 640 ns 1 28 us 2 56 ys 10 486 ms 10 ns or 20 ns bins are not available 1 ns 20 ppm of bin width 100 ps 10 ppm of delay from SYNC BUSY output Time bins are synchronous with the SYNC BUSY output 2 5 ns pk pk with respect to the TRIGGER input 45 ns from trigger to first bin Rising edge of SYNC BUSY output oc curs at the beginning of the first bin However signal pulses arriving 25 ns after the trigger will be counted in the first bin Rising edge triggers next time bin 4 MHz 250 ns minimum bin width 100 ns 100 ns Rising edge of SYNC BUSY output occurs at first rising edge of EXT BIN CLK after TRIGGER The beginning of the first bin occurs at the same time Time bins are synchrono
93. b may be used to adjust the present level The trigger threshold is adjustable from 2 000V to 2 000V with 1mV resolution The minimum pulse amplitude required to trigger is 0 1V Trigger Slope The Trigger Slope key changes the trigger slope to either rising or falling edge Discriminator Level The Discriminator Level key selects the discriminator threshold as the ac tive entry field A new threshold level may be entered from the numeric keypad in units of Volts or the knob may be used to adjust the level The discriminator threshold is adjustable from 300mV to 300mV with 0 2mV resolution The minimum signal pulse amplitude required is 10 mV The Disc Out signal is the output of the discriminator Viewing this signal on an oscilloscope while adjusting the threshold can be helpful in determining the appropriate level See the Using Photomultipler Tubes section later in this manual Discriminator Slope The Discriminator Slope key changes the discriminator slope to either ris ing or falling edge If the input signal pulses are negative going then the 27 Levels Menu Aux 1 Level Aux 2 Level slope should be set to falling If the signal pulses are positive going then slope should be rising In either case the Disc Output is always active low i e a discriminated rising edge of the signal will be output as a neg ative going NIM pulse at the Disc Output The falling edges of the Disc Output are counted The Aux 1 Level key
94. d Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg nnn nn nnn nn nn nn nnn nn nn mn now nj OT Part 15 EEEEERERLLLLIIGGIIIUUILIIIIULLULLILIIILILUISILI S III NLEILLEDODCOOeLLLIHIOoLL ILLU 4GI AuGO OALEOLUDZ A ULLULLO 3 00206 340 3 00194 340 3 00359 340 3 00238 340 3 00207 340 3 00466 340 3 00466 340 3 00356 340 3 00406 340 3 00180 340 3 00194 340 3 00194 340 3 00194 340 3 00355 340 3 00355 340 3 00355 340 3 00355 340 3 00359 340 3 00359 340 3 00359 340 3 00359 340 3 00356 340 3 00356 340 3 00200 340 3 00200 340 3 00200 340 0 00025 005 0 00089 033 0 00122 053 0 00163 007 0 00165 003 0 00407 032 1 00073 120 5 0002
95. dashed cursor re gion lines and cursor marker Pen This field assigns a pen number to any curve fit which may be drawn on the Screen Return This key returns to the Setup Plotter menu The Return key will return to the main Setup menu 44 Setup Printer Printer Type Eeo Printer Type Return Setup Menu The Setup Printer menu is used to select the type of printer attached to the parallel printer port The PRINT key prints the screen to the printer Printer Printer Type Return This function toggles the Printer Type between Epson and HP Epson is used for any Epson compatible graphics dot matrix printer and HP is used for an HP LaserJet laser printer or compatible The Return key will return to the main Setup menu 45 Setup Menu Setup Screen pn Move Right Move Left Return The Setup Screen menu is used to adjust the position of the display on the screen The display area may be moved left and right Screen Move Right Move Left Return This function moves the display to the right on the screen This function moves the display to the left on the screen The Return key will return to the main Setup menu 46 SAVE MENU Introduction The Save menu is used to save data and parameters to disk The Disk Utilities menu can erase files and format blank disks Files are saved as DOS files and can be read by a DOS compatible computer with a 3 5 di
96. data dump command to transfer data from the SR430 to the PC Using a 12 MHz AT a 16k record takes 0 8 second to transfer to the PC Example program using Microsoft C V5 1 and the National Instruments GPIB card This program assumes that a TTL trigger source is connected to the TRIGGER input This program assumes that the SR430 is installed as device mcs using IBCONF include lt stdio h gt include lt dos h gt include lt conio h gt include lt stdlib h gt include decl h National Instruments Header File void main void int X ibfind char Function Prototypes for GPIB Calls void ibwrt int char int void ibrd int char int void ibrda int char int void ibwait int int void ibstop int void ibrsp int int void main void int i int sr430 int sp int buff 2000 char tstr 20 99 Program Examples if sr430 ibfind mcs lt 0 Find Device printf Cannot Find Device MCS n exit 0 ibwrt sr430 OUTP 1 6 Direct SR430 output to GPIB interface ibwrt sr430 BREC 1 6 Set Record Length to 1024 Bins iowrt sr430 TRLV 5 7 Set Trigger Level to 5 Volts ibwrt sr430 TRLV 5 Query Trigger Level iord sr430 tstr 20 tstr ibcnt 0 Terminate Received String printf Trigger Level s n tstr ibwrt sr430 CLRS 4 Reset SR430 to Clear state clear data memory ibwrt sr430 SSCN 4 Start Scan next trig
97. data point This allows peaks and valleys in the data to be read easily When seeking mean the X position of the cursor marker is the center of the cursor region and the Y position is the mean of the data within the region When a spot cursor region is used the cur sor marker is confined to a single X screen location However depending upon the horizontal scaling each X screen location may represent multi ple data points The cursor marker can still seek the minimum maximum or mean of the data at a single X screen location This function turns the grid display on and off The grid is the set of dot ted lines on the graph which mark each scale division 36 SETUP MENU Introduction The Setup menu is used to configure the printer plotter and computer in terfaces and set the sound and clock calendar parameters Setup Commun Communications Setup Sound Setup Time Setup Plotter Plotter Setup Printer Setup Screen Each Setup activates sub Each sub menu is described detail in the following pages 37 Setup Menu Setup Communications Output To RS 232 Setup RS232 Setup GPB O View Queues Return Output To RS232 GPIB Setup RS232 Communication parameters in this sub menu should not be altered while the computer interface is active SETUP Communications Output To Rs232 GPIB Setup RS2
98. e To be certain that this is not a problem repeat the measurement at half the original intensity The problem of gain variation with count rate is avoided if the current in the bias network is about 20 times the output current from the PMT s anode Example If a PMT is operated so that it gives 20 mV pulses of 5 ns duration into a 50 Ohm cable then the average current at 50 MHz count rate will be 0 1 mA If the bias resistors are chosen so that the chain current is 20 x 0 1 mA 2 mA then the PMT s gain will remain constant vs count rate If this PMT is operated at 2500 vdc then the power dissipated in this base is 5 Watts There are a few other methods to avoid this prob lem which do not require high bias currents These methods depend on the fact that the majority of the output current is drawn from the last few dy nodes of the multiplier 1 Replace the last few resistors in the bias chain 8 DYNODES Figure A Resistive Divider PMT Base 108 with Zener Diodes As long as there is some re verse current through a Zener the voltage across the diodes is nearly constant This will prevent the voltage on these stages from dropping as the out put current is increased 2 Use external power supplies for the last few dy nodes in the multiplier chain This approach dissi pates the least amount of electrical power since the majority of the output current comes from low er voltage power supplies however it is the most
99. e Off 0 or On 1 ReAcquire count data from data acquisition memory Set the ReAcquire From Offset to 0 lt i lt Trigger Offset in increments of 16 AutoScale the graph Same as AUTOSCALE key Move the cursor to the on screen peak Same as PEAK key Query the Cursor Marker bin number Translate the graph to center the cursor Same as CENTER key Set the Left edge of the graph to bin i Set the Bottom of the graph to i counts or x value Set the Horizontal Screen Width to 8 bins 0 through 16k bins 22 Set the Vertical Scale to i counts division or x division in a 1 2 5 10 sequence Turn the Cursor Off 0 or On 1 Set the Cursor Width to Normal 0 Wide 1 or Spot 2 Set the Cursor Seek Mode to Maximum 0 Minimum 1 or Mean 2 Turn the Grid Off 0 or On 1 Set the Output Interface to RS232 0 or GPIB 1 Turn the Key Click Off 0 or On 1 Turn the Alarms Off 0 or On 1 Set the Hours to 0 lt i lt 23 Set the Minutes to 0 lt i lt 59 Set the Seconds to 0 lt i lt 59 Set the Month to 1 lt i lt 12 Set the Day to 1 lt i lt 31 Set the Year to 0 lt i lt 99 Set the Plotter Mode to RS232 0 or GPIB 1 Set the Plotter Baud Rate to 300 0 1200 1 2400 2 4800 3 9600 4 Set the Plotter GPIB Address to 0 lt i lt 30 Set the Plot Speed to Fast 0 or Slow 1 Set the Trace Pen Number to 1 lt i lt 6 Set the Grid Pen Number to 1 lt i lt 6 Set the Alp
100. e The time is displayed as hours minutes seconds A 24 hour format is Used The time displayed is the time when the Setup Time menu was dis played and does not advance until the menu is redrawn This key toggles the entry field from hours to minutes to seconds A new entry may be made using the knob When the knob is used the clock is set whenever the highlighted value is changed Date The date is displayed as month day year The date displayed is the date when the Setup Time menu was displayed and does not advance until the menu is redrawn This key toggles the entry field from months to days to years A new entry may be made using the knob When the knob is used the calendar is set whenever the highlighted val ue is changed Return The Return key will return to the main Setup menu 42 Setup Menu Setup Plotter The Setup Plotter sub menu configures the SR430 plotter driver Inter face plot speed and pen definitions are set in this sub menu To actually start plotting use the PLOT key to select the Plot menu Plot Mode SETUP RS 232 GPIB Baud Rate Plotter 9600 bd Plot Mode Plot Speed RS232 GPIB Baud Rate Plotter Address as low Define Pens Li Plot Speed Define Pens Trace Pen Grid Pen Alpha Pen Cursor Pen Fit Pen Return Return Plot Mode The SR430 can drive either an RS232 or GPIB interface plotter The plot ter must be HP GL compatible This function selects which interface
101. e bins which over flowed into 2 or more smaller bins each capable of 32 767 counts Thus more total counts may be accumulated for the same record time A scan is an accumulation of a number of records The number of records in a scan may be pro grammed from 1 to 65 535 TRIG gt 45ns SYNC BUSY LT Tol Ts BIN SIGNAL INPUT gt 620 ns DISC OUT Oo a 0 ACCUMULATION AND K PROCESSING TIME BIN WIDTH TIMING DIAGRAM 17 Instrument Overview TRIGGER and SYNC BUSY Data acquisition is started by a trigger The TRIG GER input is on the front panel The trigger thresh old is adjustable from 2V to 2V and the slope may be either RISE or FALL The SYNC BUSY output is a TTL level signal which serves two purposes First it can be used to synchronize the experiment timing with the actual time bins of each record Second it indicates when the unit is busy acquiring data and cannot be triggered After a trigger is recognized the SYNC BUSY out put will go high indicating the start of the first time bin The insertion delay from TRIGGER to SYNC BUSY is 45 ns SYNC BUSY will have 2 5 ns of in determinacy with respect to the trigger As a re sult the entire record starts with 2 5 ns of uncer tainty with respect to the trigger This is not a problem if the bin width is much longer than 2 5 ns but may be a problem for shorter bin w
102. e factory Performing these adjustements or replacements can result in the discriminator levels being slightly miscalibrated The discriminator offsets may be a few mV larger after repair or adjustement Remove the power cord and wait two minutes be fore replacing the cover This allows the power supply to discharge and removes the possibility of shorting out a circuit with the cover while replacing it Test and Calibration 106 USING PHOTOMULTIPLIER TUBES PHOTOMULTIPLIER SELECTION FOR PHOTON COUNTING Photomultiplier Tubes PMT s are high gain low noise light detectors They can detect single pho tons over a spectral range of 180 to 900 nm Win dowless PMT s can be used from the near UV through the X ray region and may also be used as particle detectors Photons which strike the PMT s photocathode eject an electron by the photoelectric effect This electron is accelerated toward the first dynode by a potential of 100 to 400 Vdc Secondary electrons are ejected when the electron strikes the first dy node and these electrons are accelerated toward the second dynode The process continues typi cally for 10 dynodes each providing an electron gain of about 4 to produce 1 000 000 electrons which are collected by the anode If these elec trons arrive in a 5 ns pulse into a 50 Ohm load they will produce a 1 6 mV pulse These pulses may be amplified and counted GEOMETRY There are two basic geometries for photomultipl
103. e latched into U1308B at the end of accumulation U1302 U1306 are the output ports The processor writes to these ports via the expansion connector DIGITAL TO ANALOG CONVERTER U1602 is a 12 bit D A converter which is loaded 4 bits at a time by the processor The voltage output from U1603A is 0 to 5 12V U1603B shifts and scales this output to provide 2 to 2 V U1604 multiplexes this output to 4 sample and hold ampli fiers 123 Circuit Description Circuit Description 124 art 15 EEEEERERLLLLUSLLIIIIUNILIIIIULLLULUGIUGIGIG LLLILICGELL EL A L LAAUEQIGCOGTGGOULUGULUAIUILG LGpB OlULGLG 0 LLL SR430 COMPONENT PARTS LIST es CONTROL BOARD x REF SRS part VALUE DESCRIPTION BT701 6 00001 612 BR 2 3A 2PIN PC Battery C 101 5 00177 501 30P Capacitor Ceramic Disc 50 1096 SL C 102 5 00215 501 20P Capacitor Ceramic Disc 50V 1096 SL C 103 5 00028 507 100P Capacitor Ceramic Disc 250V 1096 Y5P C 501 5 00215 501 20P Capacitor Ceramic Disc 50 10 SL C 601 5 00033 520 47U Capacitor Electrolytic 16V 2096 Rad C 602 5 00012 501 330P Capacitor Ceramic Disc 50 10 SL C 603 5 00012 501 330P Capacitor Ceramic Disc 50 10 SL C 701 5 00064 513 0047U Capacitor Mylar Poly 50V 596 Rad C 702 5 00215 501 20P Capacitor Ceramic Disc 50 10 SL C 703 5 00003 501 10P Capacitor Ceramic Disc 50 1096 SL C704 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 705 5 00012 501 330P Capacitor Cera
104. e operations alter the data in the display memory The ReAcquire function will restore the display memory to the original count data stored in the data acquisition memory The ReAcquire function re reads data from the data acquisition memory into the display memory The acquisition memory stores a number of data points equal to the Trigger Offset Bins Record while ReAcquire reads only the number of data points equal to the Bins Record ReAc quire skips the number of bins specified in the From Offset field at the be ginning of the acquisition memory before transferring data to the display memory A simplified memory map is shown below 32 Return Mode Menu Data Acquisition Memory 32704 Total Acquired Data Trigger Offset Bins Record 0 to 16320 1024 to 16384 From Offset ReAcquired Display Memory equal to Bins Record The From Offset value may be set from 0 to the Trigger Offset in incre ments of 16 bins The time corresponding to the Offset number of bins is shown below the entry field Since the Offset value may be less than the Trigger Offset bins which were not originally displayed while the data was taken may be displayed using ReAcquire The Return key will return to the first Mode menu 33 Mode Menu 34 DISPLAY MENU Introduction Translate Cursor Cursor Width Norm Cursor Seeks Max in n Translate Zoom The Display menu is used to change the graph parameters and cu
105. e processor en ables the copy buffers again and a copy is made of the next accumulation The accumulation and copy buffers are reset by forcing the adder outputs to zero during an accu mulation The accumulation memory data bus is tri stated and pulled up to FFFFH The incoming fast data bus is tri stated and pulled up to FFFFH also The fast data is complemented to 0000H by the XOR gates The carry input to the first adder is set to 1 The result is the addition of FFFFH and 0001H The adder output is 0000H and is latched into the accumulation and copy buffers COPY BUFFER ADDRESS COUNTER U1103 U1106 are counters which generate the ad dress for the copy buffer memory When copying an accumulation the counters are loaded with the same address as the fast buffer address counter The counter is clocked by copy buffer write signal which is derived from the accumulation buffer write signal When the copy is complete the starting ad dress is reloaded and the processor can read the buffer via U1016 and U1019 with each read pulse clocking the address counter Since the address automatically increments the processor can read the data at high speed STATUS AND IO U1301 is the status input port U1309A detects triggers which arrive while the previous record is still being acquired or accumulated U906B latches the SUBTRACT input and U1309B latches the IN HIBIT input Any overflow which occurs during ac cumulation will set U1308A and b
106. e specified by the FNAM command 86 Remote Programming MATH OPERATION COMMANDS When using the math commands SMTH FITS CALC and STAT the status bytes should be queried after the command is sent to check if the command generated an error Common sources of errors are divide by zero math overflow or underflow and file not on disk For example the command line FITS ESR lt lf gt will perform a curve fit and return the Standard Event Status Byte when finished The Execution Error bit may be checked to make sure that the FITS command terminated without error SMTHi FTYP i FITS PARS i LLIM i RLIM i The SMTH i command smooths the data This may take some time Use a status byte query to detect when the smoothing operation is done The parameter i selects a smoothing width smoothing width 0 5 points 1 11 points 2 17 points 3 21 points 4 25 points The FTYP command sets or reads the type of fit The parameter i selects the type of fit If i 0 the fit is a line if i21 the fit is exponential and if i22 the fit is Gaussian The FITS command starts the actual fitting calculations The fit takes place only within the fit region defined by the LLIM and RLIM commands The fit progresses until the change in chi squared falls below 0 196 This may take some time Use a status byte query to detect when the fit oper ation is done If the FITS command is used before the LLIM and RLIM commands have
107. ed file To select a file activate the cursor with the CURSOR key and use the knob to scroll the file entries Make sure the selected file is the correct file before pressing this key The Return key will return to the main Save menu Re turn also removes the catalog display screen and re stores the graph 51 Save Menu 52 RECALL MENU Introduction The Recall menu is used to recall data and parameters from disk Files may be recalled only when the unit is in the CLR state data memory cleared The Disk Utilities menu can erase files and format blank disks Recall Trace Recall Settings RECALL E Recall Trace zj m Recall Settings Recall System Disk Utilities Recall System File Name Catalog On Off Return Disk Utilities Format Disk Erase File Return Recall Keys Each Recall Key activates a sub menu The Recall Trace Settings and System menus are similar 53 Recall Menu Recall Trace File Name TEST DAT Catalog Off Return The Recall Trace sub menu is used to read a data record and display from a disk file Note that the Mode menu parameters and the graph scal ing will be set to those corresponding to the disk data Data may not be Recall Trace File Name Catalog On Off TEST recalled unless the unit is in the CLR state data memory is reset Pressing this key will recall the data settings
108. egative high voltage power supply The simplest design consists of a resistive voltage divider as shown in Figure A In this configuration the voltage between each dy node and so the current gain at each dynode is the same Typical current gains are 3 to 4 and so there will typically be 3 to 4 electrons leaving the first dynode with a variance of about 2 electrons This large relative variance due to the small num PHOTOCATHODE PHOTON HIGH VOLTAGE ber of ejected electrons gives rise to a large varia tions in the pulse height of the detected signal Since statistical fluctuations in pulse height are caused by the low gain of the first few stages of the multiplier chain increasing the gain of these stages will reduce pulse height variations and so improve the plateau characteristics of the PMT To increase the gain of the first few stages the resis tor values in the bias chain are tapered to increase the voltage in the front end of the multiplier chain The resistor values are slowly tapered so that the electrostatic focusing of electrons in the multiplier chain is not adversely affected Current for the electron multiplier is provided by the bias network Current drawn from the bias net work will cause the dynode potentials to change and so change the tube gain This problem is of special concern in lifetime measurements The shape of exponential decay curves will be changed if the tube gain varies with count rat
109. elp screen The PRINT key is the one key for which no help is available Pressing PRINT at any time will print the screen including the help screens LOCAL When a host computer places the unit in the RE MOTE state no keyboard or knob input is allowed To return to front panel operation press the HELP key Guide To Operation 24 Rear Panel BNC Connectors POWER ENTRY MODULE The power entry module is used to fuse the AC line select the line voltage and block high fre quency noise from entering or exiting the instru ment Refer to the first page of this manual for in structions on selecting the correct line voltage and fuse IEEE 488 CONNECTOR The 24 pin IEEE 488 connector allows a computer to control the SR430 via the IEEE 488 or GPIB in strument bus The address of the instrument is set in the SETUP GPIB menu Also a GPIB plotter with HPGL compatible graph ics may connected to the IEEE 488 port In this case the SR430 will control the plotter to generate plots of the screen graph In this case use the SETUP PLOTTER menu to configure the SR430 to use a GPIB plotter IEEE 488 GPIB Connector Parallel Printer Connector 25 Guide To Operation REAR PANEL PC Keyboard Connector RS232 Connector RS232 CONNECTOR The RS232 interface connector is configured as a DCE transmit on pin 3 receive on pin 2 The baud rate parity and word length are pro grammed from the SETUP RS23
110. erminated without error Since the Save Trace command may take a long time to ex ecute it is important that the host computer inter face does not time out while waiting for the re sponse to the ERRS query In the case where the host interface times out before the ERRS re sponse the host program must wait before send ing the ERRS query Remote Programming DETAILED COMMAND LIST The four letter mnemonic in each command sequence specifies the command The rest of the sequence con sists of parameters Multiple parameters are separated by commas Parameters shown in are optional or may be queried while those not in are required Commands that may be queried have a question mark in parentheses after the mnemonic Commands that may ONLY be queried have a after the mnemonic Commands that MAY NOT be queried have no Do not send or as part of the command The variable i is an integer The variable x is a real number All variables may be expressed in integer floating point or exponential formats i e the number five can be either 5 5 0 or 5E1 IMPORTANT NOTE All responses are directed to the interface selected in the Setup Communications Output To RS232 GPIB function regardless of which interface received the query Use the OUTP com mand to select the correct interface at the beginning of every program LEVEL CONTROL COMMANDS TRLV 2 x The TRLV command sets or reads the trigger threshold level The
111. esent value of a particular parameter may be determined by querying the SR430 for its val ue A query is formed by appending a question mark to the command mnemonic and omitting the desired parameter from the command Values returned by the SR430 are sent as a string of ASCII characters terminated by a carriage return cr RS232 and by a line feed If2 on GPIB If multiple queries are sent on one command line separated by semicolons of course the answers will be returned individually each with a terminator Examples of Command Formats Remote Programming DCSL 0 lt Set discriminator slope to positive Set the discriminator level to 10 mV 10E 3 Volts DCLV 10E 3 lt IDN lt gt Queries the device identification SSON lt Starts data acquisition same as START key RSON lt gt Queries the number of records per scan INTERFACE READY AND STATUS The Interface Ready bit in the Serial Poll Status Byte signals that the SR430 is ready to receive and execute a command When a command is re ceived this bit is cleared indicating that an opera tion is in progress While the operation is in progress no other commands will be processed Commands received during this time are stored in a buffer to be processed later Only GPIB serial polling will generate a response while a command is in progress When the command execution ter minates the Interface Ready bit is set again and new commands will be processed
112. f the number of bins being displayed is very large the autoscale operation may take a noticeable amount of time 727 0 usec AUTOSCALE be pressed at time during or after data acquisition While the unit is BUSY accumulating and updating the graph AUTO SCALE may be used to periodically re scale the graph as the data accumulates beyond the top of the graph AUTOSCALE only operates on the data which is displayed on the graph Data corresponding to bins which are not shown do not figure in the auto scaling calculations PEAK Pressing PEAK will center the cursor region around the maximum data value on the screen The cursor marker will be positioned at the Min Max or Mean of the data within the region de pending upon the cursor mode The PEAK key only searches the data which is on the screen If the maximum value occurs at more than one loca tion then PEAK will find the one closest to the left edge CENTER The CENTER key will horizontally translate the graph to place the bin corresponding to the cursor marker at the center of the graph The horizontal scale is not affected If the translation can only be accomplished by displaying bins prior to bin 0 or after the last bin then no action is taken This can occur when trying to center a bin which is within half of the horizontal scale of either end of the record NORM NORM will normalize the entire record of data to the data value of
113. f floating point data 40 4 byte real range of data if floating point data 44 4 byte integer records accumulated 48 2 byte integer data point for bin 0 50 2 byte integer data point for bin 1 continues until last data point in record If the trace file represents integer count data the data points are simply 2 byte integers which are the counts in each bin If the file was saved as floating point data after a CALC function then the data is stored differ ently Each data point is stored as a 2 byte integer which can be converted into the correct floating point value as follows Float Value Integer data point 65 536 x range of data minimum data value SETTINGS FILE Byte Type Explanation 0 11 ASCII character The string SRA30 SET lt cr gt appears at the beginning of the file 12 2 byte integer bin width 0 19 see BWTH command 14 15 reserved 16 2 byte integer bins per record 1 16 see BREC command 18 2 byte integer Trigger Offset 20 2 byte integer Records per Scan 22 4 byte integer records accumulated 26 2 byte integer Trigger Level 001V 28 29 reserved 30 2 byte integer Discriminator Level 0002V 32 35 reserved 36 2 byte integer Toggle Count 38 39 reserved 40 2 byte integer AUX 1 Level 005 V 42 2 byte integer AUX 2 Level 005 V 95 Remote Programming 96 PROGRAM EXAMPLES IBM PC IBM BASIC using the RS232 interface In this example the IBM PC serial port COM1 is used at 9600 baud Configure
114. f the data is in floating point representation as a result of a Math function zooming in is limited by the 16 bit resolution of the data Vertical zooming takes place about the cursor marker if the cursor is on or the center of the screen if the cursor is off Horizontal scaling is in powers of 2 from 8 bins up to 1k bins across the screen and above 1k bins in increments of 1k up to the number Bins Record 1k to 16k across the full screen Horizontal zooming takes place about the cursor marker position unless the cursor is too close to the be ginning or end of the record In this case zooming will leave the left or right edge of the graph unchanged This function turns the cursor region and cursor marker on and off It is sometimes desirable to turn off the cursor before printing the screen This function selects the width of the cursor region defined by the vertical dashed lines on the graph Normal width is 1 2 of a division Wide is 1 division and Spot is a single X position on the screen the cursor marker is a single dashed line The cursor region moves to the left and to the right a single pixel at a time There are 496 pixels across the graph The cursor marker searches the data points within the cursor region for the maximum or minimum data value or calculates the mean of the re gion This key toggles between Max Min and Mean When seeking minimum or maximum the cursor marker is located at the minimum or maximum
115. f the graph This value is changed whenev er the graph is translated up or down The graph may be translated in the vertical direction in incre ments of 1 80 of the screen or 1 count whichever is larger The Number of Records accumulated is dis played in the bottom right corner While data is be ing acquired and accumulated the graph is being constantly updated to display the data accumulat ed so far Each time the data is updated the num ber of records is updated When the scan is com plete the graph will show the total accumulated data and the number of records accumulated will be equal to the programmed number of records per scan While data acquisition is in progress the graph shows the data accumulated and the num ber of records completed CURSOR DISPLAY The Cursor Region is the graph region between the vertical dashed lines The cursor region may be set to 1 division wide 1 2 division norm or a single vertical line spot The cursor region does not change with horizontal scaling The Cursor Marker is a small square which seeks the mini mum maximum or mean of the data within the cursor region When seeking min or max the cur sor marker is located at the position of the data point which is the min or max This allows peaks and valleys in the data to be easily read out When seeking the mean the X position of the cursor marker is at the center of the cursor region and the Y position is the mean of the data with
116. f the serial poll byte The value is re turned as a decimal number from 0 to 255 If the parameter i 0 7 is in cluded the value of bit i is returned Reading this byte has no effect on its value The PSC command sets the value of the power on status clear bit If i21 the power on status clear bit is set and all status registers and enable registers are cleared on power up If i 0 the bit is cleared and the status enable registers maintain their values at power down This allows the a service request to be generated at power up The ERRE command sets the error status enable register to the decimal value i 0 255 The ERRE command queries the value of the error stat us enable register 91 Remote Programming ERRS i The ERRS query reads the value of the error status byte The value is returned as a decimal number from 0 to 255 If the parameter i 0 7 is in cluded the value of bit i is returned Reading the entire byte will clear it while reading bit i will clear just bit i MCSE i The MCSE command sets the multichannel scaler MCS status enable register to the decimal value i 0 255 The MCSE command queries the value of the MCS status enable register MCSS i The MCSS query reads the value of the multichannel scaler MCS stat us byte The value is returned as a decimal number from 0 to 255 If the parameter i 0 7 is included the value of bit i is returned Reading the entire byte will clear it while readin
117. fixed they simply turn on and off The indicators are shown below ALT Indicates that the ALTERNATE keypad is in use The ALTERNATE keypad uses the alphabetic leg ends printed below each key The ENTER key has the same function in the ALTERNATE keypad To enter the ALT mode press the ALT key once Pressing the keys will now enter alphabetic char acters into the active entry field To return to the normal keypad press the ALT key again Gas RENEE Trigd RATE ERR SRQ REM Add OFLW Act TT Trigd Flashes on whenever a record is triggered during data acquisition Trigd does not flash unless the unit is in the BUSY state after the START key is pressed Triggers received during other times will not flash this indicator Add or Sub This indicates whether the next record will be add ed to or subtracted from the accumulation Sub is may be active if the accumulation mode is set to SUB TOGGLE or EXTERNAL RATE This flashes when a trigger is received while SYNC BUSY is high i e the unit is still acquiring data from a previous trigger These triggers are ig nored and do not contribute to the data accumula tion The extra triggers simply flash the RATE indi cator Only triggers received while SYNC BUSY is low will trigger a data record OFLW This indicator will turn on during accumulation if any bin accumulates more than 32 767 counts in ADD accumulate mode or 16 384 counts in 19 Guide To Ope
118. frequency the output of U406 will be 12 5 MHz which is the bin clock for 40 ns bins Each half cycle of the out put clock is a 40 ns count bin for a total period of 80 ns or 12 5 MHz The 4 quadrature signals are combined in U410 to provide signals to reset the counters latch the count data write the data to memory etc These signals are synchronous with the count bins Circuit Description There are 2 count channels even and odd While one counter is counting the other is storing data and resetting The complete cycle time is 40 ns of counting and 40 ns of resetting and storing 2 counters are needed to provide 100 counting duty cycle U406A provides the 2 count gates GATE_ODD and GATE_EVEN An even and odd versions of the control signals are also required When the bins are clocked externally using the EXT BIN CLK the first external bin clock after the trigger clocks latch U313A The output of U313A enables the external bin clock through U407A Multiplexers U408 and U409 reconfigure the bin clock generator circuit for external clocking U404B now passes the external clock without di viding by 2 U405AB divides the external clock fre quency by 2 and provides a square wave output U406AB passes this clock to provide the gate and control signals to the counters Each gate is a half cycle of the output and equals the external clock period In order to maintain adequate timing mar gin for the control signals the minimum high a
119. g To remedy the situation turn the unit off and hold down the CLR key while turning the unit back on This causes the unit to reinitialize the memory and assume the default setup TESTING THE DATA ACQUISITION HARDWARE COUNTERS MEMORY AND AC CUMULATOR 103 Unplug all cables from the unit and recall the de fault setup by holding the CLR key down while turning the unit on This test requires a simple TTL rate generator to trigger the SR430 The rate generator output should be attached to the TRIGGER input of the SR430 The trigger rate should be variable up to 2 kHz Set the Trigger Level and Slope to trigger on the generator output The rear panel TEST output is used as the source of signal pulses The TEST output is a 50 NIM level output at 50 MHz The pulses are synchro nous with the BIN CLK and thus a known number of pulses will occur within each bin Use a BNC cable to connect the TEST output to the SIGNAL input on the front panel Set the Dis criminator Level to 300 0 mV and the Discrimina tor Slope to Negative In the Mode menu select a Bin Width of 40 ns and set the Bins Record to 1k Set the Records Scan to 1000 Set the TTL rate generator to a frequency of 1 kHz Press the START key to begin acquiring data The 1000 records should require 1 second to ac quire The Status indicator should display Trigd and BUSY for the 1 second There should not be a RATE error since the record time is 1024 x 40 ns
120. g bit i will clear just bit i STATUS BYTE DEFINITIONS The SR430 reports on its status by means of four status bytes the serial poll byte the standard status byte the MCS status byte and the error status byte Upon power on the SR430 may either clear all of its status enable registers or maintain them in the state they were in on power down The PSC command determines which action will be taken SERIAL POLL STATUS BYTE o it name usage Scan Ready No scan data acquisition in progress 1 Interface Ready command execution in progress 2 Error An unmasked bit in the error status byte has been set 3 MCS An unmasked bit in the MCS status byte has been set 4 MAV The interface output buffer is non empty 5 ESB An unmasked bit in the standard status byte has been set 6 SRQ SRQ service request bit 7 Unused The Error MCS and ESB bits are set whenever any unmasked bit in their respective status registers is set A bit is unmasked by setting the corresponding bit in the corresponding enable register The Serial Poll Status bits are not cleared until the condition which set the bit is cleared Thus these bits give a constant summary of the enabled status bits A service request will be generated whenever an unmasked bit in the Serial Poll register is set Note that service requests are only produced when the bit is first set and thus any condition will only produce one service request Accordingly if a service req
121. g cable delay to the TEST cable can also move the pulses into new bins In this way every bin can be tested eventually Once these tests are completed any bin width up to 327 us and any record length can be tested Re member that the TEST pulses come every 20 ns and that the first bin will always receive 1 less count per trigger than the rest of the bins Also for longer record times the 1 kHz trigger rate will be too fast and generate RATE errors These may ei ther be ignored or the trigger rate lowered Each bin can only count up to 32767 in a single trigger so bins wider than 327 us will overload in a single trigger The wider the bin the less accumulation is allowed Adjust the Records Scan accordingly If problems are encountered a scope should be used to verify that SYNC BUSY BIN CLK OUT and DISC OUT are functioning properly Set the Records Scan to 0 and start data acquisition Records will acquire without end allowing these signals to be examined at length The SYNC BUSY output is a TTL level signal which goes high 45 ns after the trigger is received The signal goes low after the record is acquired and accumulated This time is equal to N x bin width 250 ns 150 us where N is the number of records per bin Terminate this output into a high impedance The BIN CLK OUT is a NIM level 50 clock signal which indicates the bin boundaries Each transition of the BIN CLK OUT is a bin boundary The BIN CLK is active only w
122. ger starts scan do ibrsp sr430 amp sp Check Status using serial poll while sp amp 1 While Scan is still in progress ibwrt sr430 BINB 5 Dump the Scan ibrd sr430 char buff 2048 Read 2048 bytes back from SR430 each point is 2 bytes for i20 i lt 1024 i Print data record to screen printf Bin d Count d n i buff i printf Program Executed Normally n 100 Program Examples IBM PC IBM BASIC using the National Instruments GPIB interface Refer to the previous example for a discussion about the National Instruments GPIB interface This BASIC program does exactly the same thing as the C program in the previous example Be sure to use the file DECL BAS provided by National Instruments to start your program DECL BAS contains the initializa tion procedures for the GPIB driver 10 EXAMPLE PROGRAM USING MICROSOFT BASIC AND THE NATIONAL INSTRUMENTS GPIB CARD 20 THIS PROGRAM ASSUMES THAT A TTL TRIGGER SOURCE IS CONNECTED TO THE TRIGGER IN PUT 30 THIS PROGRAM ASSUMES THAT THE SR430 IS INSTALLED AS DEVICE MCS USING IBCONF 40 50 USE THE FILE DECL BAS PROVIDED BY NATIONAL INSTRUMENTS TO INITIALIZE THE GPIB DRIV ER 60 100 CLEAR 60000 IBINIT1 60000 IBINIT2 IBINIT1 3 BLOAD bib m IBINIT1 110 CALL IBINIT1 IBFIND IBTRG IBCLR IBPCT IBSIC IBLOC IBPPC IBBNA IBONL IBRSC IBSRE IBRSV IBPAD IBSAD IBIST IBDMA IBEOS IBTMO IBEOT IBRDF IBWRTF IB
123. gger Level Pressing the first soft key will highlight the Trigger Level value The Trigger Level may then be adjusted with the knob or programmed with a value using the nu meric entry keys Each menu is described at length in a following section DATA ACQUISITION STATUS The Data Acquisition status is displayed in the upper left corner The acquisition status is always displayed and is always in inverse video CLR indi cates that the accumulation memory and counters are reset The data are all zeroes All parameters can be changed while in the CLR state Pressing the START key will start data acquisition and the status will change to BUSY While in the BUSY state data is graphed as it accumulates and pa rameters related to the data acquisition may not be changed When the programmed number of records per scan has accumulated then data ac quisition is DONE The graph will show the final accumulation Acquisition may be paused during BUSY by pressing the STOP key The status is then PAUSE While in the PAUSE state the START key continues data acquisition and the STOP key will reset to the CLR state In general pressing the STOP key twice in succession will reset to the CLR state STATUS INDICATORS In addition to the acquisition status there are a number of other status indicators which may be displayed These indicators are visible only when the condition they represent is present The posi tion of these indicators is
124. gin acquiring data the number of bins per record and the number of records per scan must be programmed The record length N is the num 13 Instrument Overview ber of time bins in a single record Each trigger will take N data points corresponding to N sequential time bins N may be programmed from1024 to 32704 including Trigger Offset Records are accumulated until the number of records per scan R have been acquired R may be programmed from 1 to 65536 If R is set to 0 free run then accumulation continues without end This mode is convenient when timing an ex periment since BIN CLK and SYNC BUSY are out put only when data is being acquired When R is 0 every trigger will output SYNC BUSY and BIN CLK without stopping after a programmed number of triggers After the record length and scan length have been programmed data acquisition can be started When the START key is pressed or a START command is received from the computer interface data acquisition begins The next TRIGGER wvill start the first record and count data will be stored Successive triggers will acquire records which are accumulated until the number of records per scan have been taken During this time the unit is BUSY and the SYNC BUSY and BIN CLK outputs are active After the number of records per scan have been accumulated data acquisition is halted The unit is now in the DONE state Triggers which arrive while the unit is DONE are ignored and
125. hanumeric Pen Number to 1 x i lt 6 Set the Cursor Pen Number to 1 lt i lt 6 Set the Fit Pen Number to 1 lt i lt 6 Set the Printer Type to Epson 0 or HP 1 SAVE AND RECALL FNAM string Set the current File Name to SR430 Multichannel Scaler String SVTR SVST SVSS RCTR RCST RCSS MATH SMTH i FTYP i FITS PARS i LLIM i RLIM i CALC ARGT i ARGM i STAT SPAR i Save the Trace Data to the file specified by FNAM Save the Settings to the file specified by FNAM Save the System Configuration to the file specified by FNAM Recall the Trace Data from the file specified by FNAM Recall the Settings from the file specified by FNAM Recall the System Configuration from the file specified by FNAM Smooth the data using 5 pts 0 11 pts 1 17 pts 2 21 pts 3 or 25 pts 4 Set the Fit Type to Line 0 Exponential 1 or Gaussian 2 Start the Fit Calculation Query Fit Parameter tO 0 a 1 b 2 or c 3 Set the Left Limit of the curve fit region to bin i where 0 x i lt Right Limit Set the Right Limit of the curve fit region to bin i where Left Limit lt i lt Last bin in record Start a Calculation Set the calculation Argument type to Constant 0 or File 1 Set the Constant Argument to x Start the Statistical Calculations Query Statistical Parameter mean 0 deviation 1 area 2 baseline area 3 PRINT AND PLOT PRSC PALL PTRC PCUR P
126. he electron multiplier PMT hous ings which cool the PMT to about 20 C can dra matically reduce the dark count from a few kHz to a few Hz The residual counts arise from radio active decays of materials inside the PMT and from cosmic rays Using Photomultiplier Tubes PMT s which are specifically designed for photon counting will specify their noise in terms of the rate of output pulses whose amplitudes exceed some fraction of a pulse from a single photon More of ten the noise is specified as an anode dark cur rent Assuming the primary source of dark current is thermionic emission from the photocathode the dark count rate is given by Dark Count in kHz 6 x Dark Current in nA Gain millions PMT BASE DESIGN PMT bases which are designed for general pur pose applications are not appropriate for photon counting General purpose bases will not allow high count rates and often cause problems such as double counting and poor plateau characteris tics A PMT base with the proper high voltage ta per bypassing snubbing and shielding is re quired for premium photon counting performance CAUTION Lethal High Voltages are used in PMT applications Use extreme caution when working with these devices Only those experienced with high voltage circuits should attempt any of these procedures Never work alone DYNODE BIASING A PMT base provides bias voltages to the PMT s photocathode and dynodes from a single n
127. he serial number is 00001 and the firmware version is 007 The LOCL command sets the RS232 local remote function If i 0 the SR430 is LOCAL if i 1 the SR430 will go REMOTE and if i22 the SR430 will go into LOCAL LOCKOUT state The states duplicate the GPIB local remote states In the LOCAL state both command execution and keyboard input are allowed In the REMOTE state command execu tion is allowed but the keyboard and knob are locked out except for the HELP key which returns the SR430 to the LOCAL state In the LOCAL LOCKOUT state all front panel operation is locked out including the HELP key STATUS REPORTING COMMANDS The Status Byte definitions follow this section CLS ESE i ESR i SRE i STB i PSC i ERRE i The CLS command clears all status registers The ESE i command sets the standard status byte enable register to the decimal value i 0 255 The ESE command queries the value of the status byte enable register The ESR query reads the value of the standard status byte The value is returned as a decimal number from 0 to 255 If the parameter i 0 7 is included the value of bit i is returned Reading the entire byte will clear it while reading bit i will clear just bit i The SRE i command sets the serial poll enable register to the decimal value i 0 255 The SRE command queries the value of the serial poll enable register The STB query reads the value o
128. he time bins with respect to the experiment One way to accomplish this is to trig ger the SR430 with the experiment s master rate generator and use the SYNC BUSY which is de layed from trigger by only 45 ns to trigger the ac tual experiment 77 Instrument Setups Instrument Setups 78 REMOTE PROGRAMMING The SR430 Multichannel Scaler Averager may be remotely programmed via either the RS232 or GPIB IEEE 488 interfaces Any computer sup porting one of these interfaces may be used to program the SR430 Both interfaces are receiving at all times however the SR430 will send re sponses only to the interface specified in the Setup menu Output To RS232 GPIB function Use the OUTP command at the beginning of every program to direct the responses to the correct in terface All front and rear panel features except power may be controlled COMMUNICATING WITH GPIB The SR430 supports the IEEE 488 1 1978 inter face standard It also supports the required com mon commands of the IEEE 488 2 1987 stan dard Before attempting to communicate with the SR430 over the GPIB interface the SR430 s de vice address must be set The address is set in the Setup GPIB menu and may be set between 0 and 30 COMMUNICATING WITH RS232 The SR430 is configured as a DCE transmit on pin 3 receive on pin 2 and supports CTS DTR hardware handshaking The CTS signal pin 5 is an output indicating that the SR430 is ready while the DTR s
129. hed into U512 during the even gate At the same time the odd counter is reset Latched data will be written into memory during the next odd gate while the counter is counting the next odd data point U512 is a FAST latch since the lower 8 bits are used during short bin widths The upper 8 bits are latched by U511 which is an HC latch since these bits are used only when the bin widths are long U508 detects counter overflow and latches the condition in the MSB Thus the count range is 32 768 with one overflow detection bit SHIFT REGISTER INPUTS The shift registers are used for the 5 ns bin width Since each 5 ns bin can only have either one count or no counts a counter is not needed In stead the output of the pulse sorter is fed into a shift register which stores the state of each 5 ns sample either a one or a zero U703B divides the 200 MHz clock by 2 The 100 MHz and 100 MHz outputs clock 2 8 bit shift reg isters The odd register U705 and U706 is clocked by 100 MHz and the even register U707 and U708 is clocked by 100 MHz Each register stores every other 5 ns data point Every 80 ns the LATCH signal goes high U704AB synchronize the LATCH signal to the 2 100 MHz clocks The synchronized latch signals clock the data latches U713 and U714 Since each shift register clocks at 10 ns intervals the latches catch the most recent 8 bits of data in each register The 2 latches to gether capture the most recent 16 5 ns bins
130. hile during the record acquisi tion time N x bin width Terminate this signal into 50 The DISC OUT is a NIM level 50 signal which in dicates that the discriminator has detected a pulse When using the TEST signal the DISC OUT should be a 50 MHz signal Terminate this signal into 50 If all signals check out and problems still exist contact the factory for more information COUNTING PROBLEMS There are several reasons why the SR430 may not seem to be counting correctly 1 Bad triggering The trigger input may not be dis 104 criminated correctly To check the trigger slope and level set the Records Scan to 0 and press START Records will be triggered indefinitely Check the SYNC BUSY output on a scope This signal only occurs after a trigger is recognized and lasts only for the record acquisition and accumula tion time Check that the TRIGD indicator on the screen flashes for each trigger 2 Incorrect discriminator levels or slopes Verify that the discriminator settings are correct Use the DISC output to check the discriminator output pulses on an oscilloscope 3 Signal inputs are overloaded Check that the in puts are lt 300 mV or if the signal exceeds 300 mV that the overloads do not last longer than 10 us If the overload lasts longer than 10 us the in put amplifiers will not recover for about 200 ns 4 Incorrect bin width Check that the bin width is set correctly A too narrow bin will result in smalle
131. i or VSCL x commands change the vertical scale while leaving the BOTM value unchanged The parameter i is used when the graph displays integer count data The value of i is the number of counts per vertical division and ranges from 1 to 5000 in a 1 2 5 10 sequence The value of i is rounded down to the nearest allowed scale The parameter x is used when the graph displays floating point data The value of x is the vertical scale per division Allowable x values proceed in a 1 2 5 10 sequence The value of x is rounded down to the nearest al lowed scale There is no practical maximum value for x the graph simply compresses to a line However there is a minimum value of x which de pends upon the range of the data maximum data value minimum data value Because the floating point data is single precision the minimum value of x is 0 0796 of the range of the data The graph may be expand ed to show 0 55 8 divisions of the data range The CURS command sets or reads the cursor on off condition If iO the cursor is off If i1 the cursor is on The CURW command sets or reads the cursor width If i20 the cursor is normal if i21 the cursor is wide and if i 2 the cursor is a spot cursor The CURM command sets or reads the cursor seek mode If i 0 the cur sor marker seeks the maximum if i 1 the marker seeks the minimum and if i 2 the marker seeks the mean The GRID command sets or reads the grid on off condition If i20 the grid is off
132. idths In these cases the SYNC BUSY output should be used to trigger the experiment Since the record is synchronized to SYNC BUSY there will be no in determinacy of the time bins with respect to the experiment One way to accomplish this is to trig ger the SR430 with the experiment s master rate generator and use the SYNC BUSY which is de layed from trigger by only 45 ns to trigger the ac tual experiment After a trigger the unit is busy acquiring and accu mulating data During this busy time no new trig gers will be recognized After SYNC BUSY returns low a new trigger may occur The busy time is Tbusy N Tpin N 250 ns 150 ps where Tbin is the bin width 5 ns to 10 5 ms and N is the number of bins per record 1024 to 32704 The first term is the actual record length and equals the real time duration of the data ac quisition Counts received during the time NYTpin after the trigger are captured The second term is the time needed to accumulate the record i e add the data to the sum of all previous data Accumula tion takes 250 ns per bin The last term is a fixed overhead for processing For example if N 1k bins and Thin 5 ns then Tpusy 411 The maximum trigger rate would then be 2400 Hz When the bin width is programmed to be much larger than 250 ns then the busy time is almost to tally due to the real time data acquisition and virtu ally no time is lost processing or accumulating 12 SYNC B
133. ier tubes head on and side on types The head on type has a semitransparent photocathode and a linear array of dynodes The head on types offer large photocathodes with uniform sensitivity and lower noise These PMT s must be operated at a higher voltage and are usually larger and more expensive than the side on types Side on types have an opaque photocathode and a circular cage of dynodes SPECTRAL RESPONSE There are a variety of materials which are used as photocathodes the workfunction of the photoca thode will determine the spectral response and will influence the dark count rate of the PMT For photon counting the figure of merit is the quan tum efficiency of the PMT A 1096 quantum effi ciency indicates that 1 in 10 photons which strike the photocathode will produce a photoelectron the rest of the incident photons will not be detect ed The quantum efficiency is a function of wave length so select the PMT for the best quantum ef ficiency over the wavelength region of interest 107 GAIN AND RISETIME It is important to select a PMT with sufficient gain and short enough risetime to produce a detecta ble pulse for counting In addition the risetime is an important figure of merit to determine the maxi mum count rate for the tube The criteria for a detectable pulse depends on the electrical noise environment of your laboratory and the noise your preamplifier In laboratories with Q switched lasers or
134. ignal pin 20 is an input that is used to control the SR430 s data transmission If desired the handshake pins may be ignored and a simple 3 wire interface pins 2 3 and 7 may be used The RS232 interface baud rate number of data bits and parity must be set These are set in the Setup RS232 menu STATUS INDICATORS AND QUEUES To assist in programming the SR430 has 4 inter face status indicators which are displayed at the top of the screen The Activity indicator flashes whenever a character is received or transmitted over either interface The ERR indicator flashes when an error has been detected such as an ille gal command or parameter out of range The REM indicator is on whenever the SR430 is in a remote state front panel locked out The SRQ in dicator is on when the SR430 generates a service request SRQ stays on until a serial poll is completed To help find program errors the SR430 can dis play the interface buffers on the screen This screen is activated by the View Queues function in the Setup Communications menu The last 256 characters received or transmitted by the SR430 79 are displayed The View Queues screen will dis play the interface buffers as they are when the Screen is activated Any further activity will not up date the screen until a new screen is displayed us ing the View Queues key COMMAND SYNTAX Communications with the SR430 use ASCII char acters Commands may be in either UPPER or lower
135. in the fast buffer represents 8 bits of data from 8 bins Latching multiplexers U1002 and U1004 are used to convert the parallel data into serial data Every 8 addresses the fast data is latched into U1002 and U1004 The lower 3 bits of accumula tion address now select a bit within each byte to output from the multiplexers The inverse of the selected bit is bitO of the new data The other in puts to U1020 U1023 are pulled high The XOR gates are used to complement the data so that the sign of the output is correct Accumulation pro ceeds as above with the new data being 1 or 0 only 122 U1017 and U1018 are 32kbyte copy buffers which interface to the processor While data is accumu lating U1017 and U1018 can copy an image of the accumulation buffer U1014 and U1015 enable the adder outputs onto U1017 and U1018 s data bus The address to these buffer RAMs comes from a counter similar to the fast buffer address counter While copying the accumulation data this address is clocked along with the fast buffer ad dress The result is a complete copy of the accumulation memory U1014 and U1015 can then be disabled and the data from U1016 and U1018 can be read by the processor even while new records are be ing accumulated This allows the processor to dis play data while it is being acquired without interfer ing with accumulation and never displaying an incomplete accumulation When the processor is finished reading the copied data th
136. in the re gion When a spot cursor region is used the cur sor marker is confined to a single X screen loca tion However depending upon the horizontal 18 scaling each X screen location may represent multiple data points The cursor marker can still seek the min max or mean of the data at a single X screen location The Cursor Position displays the X position bin and time and the Y data of the cursor marker In the case where each X screen location represents multiple data points the actual bin corresponding to the min max or mean is displayed Pressing the CURSOR key will draw a box around the cur sor information When the cursor readout is sur rounded by a box the spin knob is to adjusts the position of the cursor region The cursor region moves in increments of one X screen location or pixel MENU DISPLAY The Soft Key menu boxes define the functions of the 6 soft keys at the right of the screen The menu boxes are grouped into menus Pressing each of the ten menu keys will display a different menu of boxes Related functions are grouped into a single menu In general pressing a soft key does one of two things One is to toggle between 2 or 3 choices directly An example is the Trigger Slope box illustrated on the previous page Press ing the second soft key toggles the slope between rising and falling The second soft key function is to highlight an entry field and knob function An ex ample would be the Tri
137. ination of bin width and 76 number of bins is a compromise in many situa tions In general do not use more bins than neces sary since the extra resolution may not yield any more information Data may need to be taken with a few combinations before the best and most convenient combination is found ACCUMULATION A single record can capture a transient counting event if there are enough counts to be statistically significant in a single shot If the count rate is very low but the signal is repetitive then multiple records may be accumulated together This in creases the counts in each bin and improves the signal to noise of each data point If a narrow bin width is used it may be necessary to accumulate many records to achieve an accept able signal to noise ratio for an individual bin In this case a wider bin width could achieve the same signal to noise per bin with less records This is because each bin will have more counts due to its longer width This is another reason not to use a bin narrower than necessary Accumulation can also be used to subtract back ground signals Using the Toggle or External modes of accumulation allows records to be sub tracted as well as added A typical experiment would add records whenever the signal is present and subtract background records without signal The TOGGLE OUTPUT or SUBTRACT INPUT can be used to synchronize the signal with the ac cumulation Using a toggle mode does have a
138. ing refers to the practice of adding a net work to the anode of the PMT to improve the shape of the output pulse for photon counting ap plications This network is usually a short piece of 50 Ohm coax cable which is terminated into a re sistor of less than 50 Ohms There are four impor tant reasons for using a snubber network 1 Without some dc resistive path between the anode and ground anode current will charge the signal cable to a few hundred volts When the sig nal cable is connected to a preamplifer or to a sig nal input the stored charge on the cable may damage the front end of the instrument If you de cide not to use a snubber network please install a 100 kOhm resistor between the anode and ground to protect your instruments 2 The risetime of the output current pulse is often much faster than the falltime A snubber network may be used to sharply reduce the falltime greatly improving the pulse pair resolution of the PMT 3 Ringing with a few nanosecond period is very common on PMT outputs especially if the fi nal dynode stages are bypassed with capacitors A snubber network may be used to cancel these rings which can cause multiple counts from a sin gle photon 4 The snubber network will help to terminate re OUTPUT SNUBBER 10 INCHES RG174 C 8 4 2 NOTE ZENER DIODES MAY REPLACED WITH RESISTORS IN LOW AVERAGE COUNT RATE APPLICATIONS Figure B PMT Base For Photon Counting
139. ion and data value When surrounded by a box indicates that the knob will move the cursor region Data Acquisition status CLR BUSY PAUSE or DONE Soft Key Definitions Pressing the corresponding soft key will either highlight a field or select an option bin 71 Y 50 cnts LLL LL AJ ri D Cursor Marker is located at the Min Max or Mean of the data within the cursor region Cursor Region is defined by these dashed lines Left most displayed bin and time bottom 0 cnts Minimum displayed Y value This Y value corresponds to the bottom of the graph DATA DISPLAY Data is graphed with accumulated counts per bin on the Y axis and bin number or time on the X axis The physical size of the graph remains con stant while the vertical and horizontal scales may be changed The graph area has a dotted grid for reference There are 8 vertical divisions and 10 horizontal divisions In addition to X and Y scaling the graph may also be translated in the X and Y di rections Data is shown in 2 modes depending upon the X scaling There are 496 pixels or X screen locations 10 cnts Div Vertical scale Right most displayed bin and time 17 25 127 Aux 2 Level Record 100 accumulated so far across the graph If the number of bins displayed is less than the 496 then each data point
140. istor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Re
141. k SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Res Network SIP 1 4W 2 Isolated Printed Circuit Board Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Part 15 EEEEEERERLLLLIIULLIUGILUIIIULLULILLIIILLILIDIULUIICITIIICILLLUO LLU OOCIHAGCLGGCLLGLGGGLeLLAI 4
142. l None Line Constant Cleared If there is a memory error when the unit is turned on then the default settings will be used instead of the set up retained in memory This can be due to a low battery The default setup may also be recalled using the RST command In this case the communications parame ters and status registers are not changed 75 Instrument Setups CHOOSING BIN WIDTH AND RECORD LENGTH A single record acquires data for a time equal to the number of bins per record times the bin width The acquisition starts from the trigger time The SR430 can acquire up to 32k bins in a single record at up to 10 486 ms per bin for a maximum record time of 343 seconds In an experimental sit uation the record time must cover the time of in terest Once the desired record time has been deter mined the bin width needs to be chosen The bin width determines the time resolution of the meas urement In general there a number of combina tions of bins per record and bin width which will yield the same record time For example 2k bins at 10 24 hs per bin and 1k bins at 20 48 hs per bin both have a record time of 20 9 ms What combi nation should be used First of all there are re strictions on the number of bins per record and the bin width There must be at least 1k bins in the record and only certain bin widths are available The bin width should reflect the desired resolution of the measurement If features a
143. l Instruments GPIB 99 Expansion Connector 117 IBM PC BASIC Nat l Instruments GPIB 101 Power Supply Board 118 Unregulated Power Supplies 118 TEST AND CALIBRATION Power Supply Regulators 118 Power 103 Screen Brightness 103 ECL Logic Board 119 Fan 103 Signal Input 119 Front Panel Tests 103 Discriminators 119 Power On Reset 103 200 MHz Clock and Trigger Sync 119 Testing Data Acquisition Hardware 103 Bin Clock Generator 119 Counting Problems 104 Pulse Sorter 120 Calibration 105 Counters 120 Signal Inputs 105 Shift Register Inputs 120 Control Signals 121 USING PHOTOMULTIPLIER TUBES PMT Selection for Photon Counting 107 TTL Logic Board 121 Geometry 107 Fast Record Buffers 121 Spectral Response 107 Fast Buffer Address Counter 121 Gain and Risetime 107 Accumulator 122 Dark Counts 107 Copy Buffer Address Counter 122 PMT Base Design 108 Status and IO 122 Dynode Biasing 108 Digital to Analog Converter 123 Snubbing 109 Cathode Shielding 110 Magnetic Shielding 110 insu io Preamplifiers 110 Power Supply Board 129 Gain Requirement 111 ECL Logic Board 132 Plateauing a PMT 111 TTL Logic Board 138 The Fast and Pretty Good Way 111 Hardware 142 TYPICAL EXPERIMENT Energy Levels of Ruby 113 ADDENDUM 145 Apparatus 113 Operation 113 rune Configuration 114 SCHEMATIC DIAGRAMS 114 CPU Board Power Supply Board ECL Logic Board TTL Logic Board Data Acquisition CIRCUIT DESCRIPTION Circuit Boards 115 Video Driver and CRT 116 CPU Board 116 Micr
144. l of the UART functions as well as baud rate generation Standard baud rates up to 19 2k can be generated from the 3 6864 MHz clock U906 buffers the out going data and control signals Incoming signals are received by U705A and U708B If the host computer asserts DTR RS232 data output from the unit will cease The RS232 port is a DCE and may be connected to a PC using a standard serial cable not a null modem cable EXPANSION CONNECTOR All control of the data acquisition hardware is through the signals on the 2 40 pin expansion con nectors Circuit Description POWER SUPPLY BOARD CAUTION Dangerous voltages are present on this circuit board whenever the instru ment is attached to an AC power source whether or not the front panel power switch is on The front panel power switch only enables the voltage regulators in the unit but the unregulated voltages are always present Always disconnect the power cord and wait at least two minutes before opening the unit Check the LED at the front edge of the power supply board The unit is safe only if the LED is OFF If the LED is ON then DO NOT attempt any service on the unit UNREGULATED POWER SUPPLIES A power entry module with RF line filter is used to configure the unit for 100 120 220 or 240 VAC The line filter reduces noise from the instru ment and reduces the unit s susceptibility to line voltage noise R1 is an inrush limiter to limit the turn on curren
145. ll save the current system informa tion Setup menu data to the file specified in the File Name field This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are saved to the root directory This key toggles the file catalog display screen on and off The use of this key is identical to the Catalog On Off function in the Save Trace sub menu above The Return key will return to the main Save menu Re turn also removes the catalog display screen and re stores the graph 50 Save Menu Disk Utilities The Disk Utilities sub menu contains the Format Disk and Erase File functions These functions should be used with care since disk data will be erased The catalog screen is displayed when in this sub menu Format Format Disk E Erase Erase File Return Pressing this key will format the disk Formatting a disk involves erasing all information on the disk and rewriting all the directory Formatting a disk destroys all data presently on the disk Use caution when choosing this function Disk capacity is 720k formatted The maximum number of directory entries is 112 This function will erase the highlight
146. lysis and calculations may be performed on the data The PLOT menu is used to plot the data graph on a plotter The TEST menu allows the user to test the keypad external keyboard knob RS232 interface printer interface disk drive video screen and memory The INFO menu displays various information screens Detailed descriptions of each menu are provided in the next section ENTRY KEYS The numeric entry keys are used to enter parame ter values directly Parameters may be entered only if their menu box is displayed and their entry field is highlighted For example if the LEVELS menus is displayed the first soft key is next to the Trigger Level box Pressing the first soft key will highlight the entry field displaying the trigger level The menu box will appear as illustrated below 22 A new trigger level may now be entered using the numeric keys For example to set the level to 0 125 press 1 2 5 EXP S or I E 1 2 5 or any combination of keys which evaluates to the correct value Note that entry is done in units of Volts The entry field will display the char acters as the keys are pressed If an error is made the backspace lt key will erase the last character and CLR will restore the field to the original value When the entry string is correct Trigger Level Trigger Slope press the ENTER key to change the trigger level to the new value If another soft key is used to
147. me equal to the period of the anode ringing PMT BASE CONCLUSIONS 1 2 3 Taper voltage divider for higher gain in first stages Bypass last few dynodes in pulsed applica tions Use a snubber circuit to shape the output pulse CATHODE SHIELDING Head on PMT s have a semitransparent photoca thode which is operated at negative high voltage Use care so that no objects near ground potential contact the PMT near the photocathode MAGNETIC SHIELDING Electron trajectories inside the PMT will be affect ed by magnetic fields A field strength of a few Gauss can dramatically reduce the gain of a PMT A magnetic shield made of a high permeability ma 110 PMT PULSE WITHOUT SNUBBER PMT PULSE WITH SNUBBER A SLOW FALLTIME PULSE SHAPE IS IMPROVED WITH A SNUBBER gt 4 2 ns terial should be used to shield the PMT PREAMPLIFIERS The output of a PMT is a current pulse This cur rent is converted to a voltage by a load resistor RINGING WITHOUT lt SNUBBER 2ns SNUBBER CANCELS RINGING ANODE RINGING CANCELED WITH SNUBBER CABLE One would like to use a large resistor to get a large voltage pulse however in photon counting it is important to maintain a high bandwidth for the output signal Since charge on the anode is re moved by the load resistance smaller load resis tances increase the bandwidth The bandwidth of a 10 pF anode with a 100 Ohm load is 300 MHz For convenience 50
148. mic 50V 80 20 Z5U AX C 37 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 38 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 39 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 42 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 43 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 101 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 102 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad C103 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C104 5 00159 501 6 8P Capacitor Ceramic Disc 50V 10 SL C 105 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C106 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C107 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 108 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C109 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 110 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C111 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C 112 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C 201 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 202 5 00002 501 100P Capacitor Ceramic Disc 50V 10 SL C203 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C204 5 00002 501 100P Capacitor Ceramic Disc 50V 10 SL C 205 5 00002 501 100P Capacitor Ceramic Disc 50V 10 SL C206 5 00225 548 1U AXIAL Ca
149. mic Disc 50 10 SL C 706 5 00061 513 001U Capacitor Mylar Poly 50V 596 Rad C 707 5 00033 520 47U Capacitor Electrolytic 16V 2096 Rad C 801 5 00178 501 62P Capacitor Ceramic Disc 50 10 SL C 802 5 00178 501 62P Capacitor Ceramic Disc 50V 1096 SL C 803 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 804 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 805 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 806 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 807 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 808 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 901 5 00003 501 10P Capacitor Ceramic Disc 50 1096 SL C 902 5 00003 501 10P Capacitor Ceramic Disc 50V 1096 SL C 903 5 00061 513 001U Capacitor Mylar Poly 50V 596 Rad C 904 5 00223 513 027U Capacitor Mylar Poly 50V 596 Rad C 905 5 00068 513 047U Capacitor Mylar Poly 50V 596 Rad C 906 5 00061 513 001U Capacitor Mylar Poly 50V 596 Rad C907 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 908 5 00012 501 330P Capacitor Ceramic Disc 50V 1096 SL C 909 5 00178 501 62P Capacitor Ceramic Disc 50V 1096 SL C 910 5 00178 501 62P Capacitor Ceramic Disc 50 1096 SL C 1001 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C1002 5 00225 548 AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1003 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1004 5 00225 54
150. must be on the graph the RLIM command can set the limit at any bin within the record The parameter i must be in the range 0 lt i lt number of bins per 87 Remote Programming OPER i CALC ARGT i ARGM x FNAM 7 string STAT SPAR i record and i must be greater than the left limit set by LLIM The OPER command sets or reads the type of math operation selected The parameter i selects the operation i operation 0 1 2 X 3 4 log 5 sqrt The CALC command starts the calculation selected by the OPER com mand This may take some time Use status byte query to detect when the calculation is done Make sure that ARGM or FNAM have been used to set the argument value before using the CALC command CALC will convert the count data into floating point data The ARGT command sets or reads the argument type The parameter i selects Constant i 0 or File i 1 The ARGM command sets or reads the constant argument The parame ter x is a real number The FNAM command sets or reads the active file name for file argu ments All file operations use the name specified by the FNAM com mand Be sure to use the FNAM string command before any file op eration commands For example FNAM MYDATA DAT will set the active file name to MYDATA DAT DOS file name conventions must be followed i e file names are 8 characters or less with an optional exten sion of up to 3 characters Subdirectories a
151. n ized to external events SIGNAL INPUT AND DISCRIMINATOR The analog signal input is labelled SIGNAL INPUT on the front panel This input is internally terminat ed into 50 The input can accept signals of ei ther polarity up to 300 mV and is protected to 5V dc The input is followed by a dc to 250 MHz amplifier This allows detection of pulses as small as 10 mV f greater sensitivity is required the SR440 remote pre amplifier can be used The SR440 can provide gains from 5 to 125 at band widths exceeding 200 MHz Following the input amplifier is a discriminator The discriminator has selectable slope and a threshold programmable from 300 mV to 300 mV in 0 2 mV steps referred to the inputs Pulse pair resolution is 10 ns and pulses of either polarity may be detected The discriminator output is labelled DISC OUT on the front panel The DISC OUT is a 50 12 NIM lev el signal showing the actual input to the counter The output is active low 0 7 V and counting oc curs on the falling edge The output is low when the signal input exceeds the threshold level with the correct slope i e the signal is higher than the threshold with positive slope or the signal is lower than the threshold with negative slope The DISC outputs are very useful when adjusting discrimina tor thresholds or determining the exact timing of the counts relative to the time bins The DISC OUT is active at all times Whenever a signal pulse exceeds
152. n Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 art 15 EEEEEERERLLLLGIIUIUIIIIIUILIIGIULLLIUILUIILLUIIULLECCA ITLLE LIHwLILLLLLALUI GULLILII 1n109 1 1 pgpgp5hLhLGG Q4 R 213 R 214 R 215 R 216 R 217 R 218 R 219 R 220 R 221 R 222 R 223 R 224 R 225 R 226 R 227 R 228 R 229 R 230 R 231 R 232 R 233 R 234 R 235 R 236 R 237 R 238 R 239 R 240 R 241 R 242 R 243 R 301 R 302 R 303 R 304 R 305 R 306 R 307 R 308 R 309 R 310 R 311 R 312 R 314 R 315 R 316 R 317 R 318 R 319 R 320 R 321 R 322 R 323 R 324 R 404 4 00031 401 4 00034 401 4 00034 401 4 00063 401 4 00021 401 4 00080 401 4 00080 401 4 00030 401 4 00030 401 4 00081 401 4 00031 401 4 00034 401 4 00021 401 4 00080 401 4 00150 407 4 00158 407 4 00063 401 4 00080 401 4 00030 401 4 00030 401 4 00081 401 4 00031 401 4 00062 401 4 00031 401 4 00031 401 4 00031 401 4 00031 401 4 00021 401 4 00103 401 4 00021 401 4 00103 401 4 00076 401 4 00076 401 4 00065 401 4 00027 401 4 00027 401 4 00065 401 4 00590 401 4 00050 401 4 00098 401 4 00062 401 4 00065 401 4 00086 401 4 00086 401 4 00032 401 4 00062 401 4 00080 401 4 00031 401 4 00080 401 4 00031 401 4 00099 401 4 00031 401 4 00086 401 4 00022 401 4 00065 401 136 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Res
153. n in the Save Trace sub menu above The Return key will return to the main Recall menu Re turn also removes the catalog display screen and re stores the graph 56 Recall Menu Disk Utilities The Disk Utilities sub menu contains the Format Disk and Erase File functions These functions should be used with care since disk data will be erased The catalog screen is displayed when in this sub menu Format Disk Format Disk Erase File LI Erase File Return Pressing this key will format the disk Formatting a disk involves erasing all information on the disk and rewriting all the directory Formatting a disk destroys all data presently on the disk Use caution when choosing this function Disk capacity is 720k formatted The maximum number of directory entries is 112 This function will erase the highlighted file To select a file activate the cursor with the CURSOR key and use the knob to scroll the file entries Make sure the selected file is the correct file before pressing this key The Return key will return to the main Recall menu Re turn also removes the catalog display screen and re stores the graph 57 Recall Menu 58 MATH MENU Introduction Math Keys The Math menu is used to smooth fit change and analyze the data in the display memory Each Math Key activates a sub menu Each sub menu is described in de tail in the following pages Smooth The Smooth
154. name will ap pear in the File Name field Activating the cursor by pressing the CURSOR key allows the knob to scroll through the directory The highlighted file name will be copied into the File Name field If the Save Trace key is now pressed the data will be saved under an existing file name and the previous version of that file will be lost A warning message will appear if the File Name is al ready in use on the disk To create a new file name use the File Name key Directory entries made by the SR430 also have a type field shown in the catalog display Files with type SET are settings type SYS are system and type TRC are bin 71 727 0 usec Save Y 50 cnts Trace L Type Size Date 06 24 88 15 47 22 SET 40 08 10 89 10 47 25 SPEC1 DAT TRC 4192 08 10 89 11 08 27 SPEC2 DAT TRC 4192 10 15 89 11 21 01 MYDATA DAT 4144 10 15 89 11 46 32 0 0 bottom 0 cnts File ABCD Catalog Free 710760 ot bin 127 1 300 msec 10 cnts Div Record 100 Return 7 48 Save Menu trace data The file type is not an extension but is infor mation stored in the directory on the disk Only files created by the SR430 have a type Files created and saved on a DOS computer will not have a type dis played The file type is not necessary it is only an aid to identifying files Return The Return key will return to the main Save menu Re turn also removes the catalog display screen and
155. nd STOP RESET keys are used to start pause and reset the counter and accumu lation memory Data acquisition can be started only if the counters and memory are in the CLEAR or reset condition all data values are zero The CLEAR condition is indicated by the CLR data acquisition status indi cator Triggers which arrive while in the CLEAR 21 Guide To Operation KEYPAD SYSTEM PRINT HELP ERES E RECALL PLOT W X TEST INFO state are ignored and SYNC BUSY and BIN CLK OUT are inactive START begins the data acquisition The first trig ger after START is pressed will trigger the first data record The data acquisition status will switch to BUSY Successive triggers will acquire records which are accumulated While the unit is BUSY the SYNC BUSY and BIN CLK outputs are active and accumulated data is graphed on the display Each successful trigger will generate a SYNC BUSY pulse and a BIN CLK pulse train Triggers received during SYNC BUSY active times are ig nored After the programmed number of records have been accumulated data acquisition is halted The unit is now in the DONE data acquisition state The final accumulated data is now graphed on the display Further triggers will be ignored and SYNC BUSY and BIN CLK OUT are inactive Pressing the STOP key while in the BUSY state pauses the data acquisition The data acquisition status will be PAUSE and no triggers will be
156. nd low time for the external clock is 100 ns This is because the bin generator does not generate quadrature signals but instead relies on both edg es of the external clock for control timing With either clock the first bin gate sets U312A whose output is the SYNC BUSY output The bin clock also passes through U205C to drive the BIN CLK OUTPUT After the record is acquired and accumulated the processor needs to rearm the trigger circuits The BIN RESET and BIN RESET signals clear the bin generators The ARM ECL signal rearms the trigger circuit ARM ECL also clears the SYNC BUSY output by clocking U312A PULSE SORTER Signal pulses can arrive at any time including a bin boundary To ensure that a pulse is counted even at a bin boundary a pulse sorter circuit is used Signal pulses clock flip flop U702A The Q output feeds the D input of U702B U702B is clocked by the 200 MHz master bin clock If the Q output of U702B is the same as its D input then the input pulse has been successfully latched into U702B When this occurs the output of U701B goes low which enables U702A to flip at the next signal pulse U702A will not be allowed to flip states until the first pulse has propagated through U702B no matter when the pulse arrived Thus pulses are latched into U702A until they are cap tured by U702B All pulses clocked into U702B will be counted 120 U703A is also clocked by the 200 MHz clock When its output and the outpu
157. nents The five main boards are mounted with their com ponent sides facing inward All boards have a silk screen printed on both sides to ease identification of parts Circuit Description VIDEO DRIVER AND CRT Potentially lethal voltages are present in this circuit Do not attempt to ser vice the CRT and Video Driver Board Refer any service problems to the fac tory CPU BOARD The CPU board contains the microprocessor sys tem All display front panel disk and computer in terfaces are on this board MICROPROCESSOR SYSTEM The microprocessor U101 is an 80C186 micro controller which integrates a fast 16 bit processor counter timers interrupt controller DMA controller and IO decoding into a single component The 80C186 uses a 24 00 MHz crystal X101 as its oscillator The instruction clock cycle is 2 oscil lator cycles or 12 0 MHz The data and lower 16 bits of address are multiplexed on ADO AD15 U201 0202 0203 latch the address A0 A19 at the beginning of each memory or IO cycle U204 and U205 are bidirectional data bus drivers which are active during the data read write portion of each memory or IO cycle The 80C186 can address 1 Mbyte of memory and 64k of IO space The memory is mapped into 4 256kbyte blocks Each block can actually have 64k 128k or 256k of physical memory Each block has 2 sockets one for the low byte and one for the high byte of data U301 and U302 are 64kbyte EPROMS holding the
158. ns The value of i is rounded to the nearest multiple of 16 ROFF may be used when the SR430 is in the DONE state DISPLAY CONTROL COMMANDS AUTS CRPK BUGP CNTR LEFT i BOTM i x HSCL i The AUTS command performs the AutoScale function This function is exactly the same as pressing the AUTOSCALE key The AUTS com mand may affect the BOTM and VSCL parameters below The CRPK command performs the same function as pressing the PEAK key The cursor region will be centered around the maximum data value on the screen The cursor marker position depends upon the cursor mode The BUGP query reads the bin number where the cursor marker is lo cated Using the BUGP query after the CRPK command reads the posi tion of the on screen peak The CNTR command performs the same function as pressing the CENTER key The graph will be horizontally translated to place the bin corresponding to the cursor marker at the center of the graph The LEFT parameter will be affected The LEFT command sets or reads the number of the bin at the left edge of the screen The LEFT i command translates the graph horizontally to place bin i at the left edge The parameter i may range from 0 to the number of bins per record minus the number of bins per screen i e the graph may not be translated to display a bin which is beyond the end of the record The BOTM command sets or reads the minimum displayed Y value The BOTM i or BOT
159. o the RS232 inter face a carriage return cr is actually sent in place of the If Press any key except PRINT to restore the screen to the graph mode The Return key will return to the main Setup menu SRS bin 71 727 0 usec Output To Y 50 cnt RS 232 GPIB Setup IDN RETRLV DCLV lg RS232 Setup epi O Receive Queue Transmit Queue View rch_Systems SR430 s n00001 ver007 10 100000 1910000 lr uera Stanford Resea Press Any Key to Continue bin O bin 127 0 msec 1 300 msec bottom 0 cnts 10 cnts Div Record 100 Return 40 Setup Sound Key Click Off Alarms Off Key Click Alarms Return Setup Menu The Setup Sound key activates the sound sub menu Key click and alarms are enabled and disabled in this sub menu Key Click On Off Alarms On Off Return This key turns the key click on and off This key enables and disables the audible alarms Alarms will sound whenever a front panel programming error or interface error occurs Alarms are also used to draw the user s attention to a message The Return key will return to the main Setup menu 41 Setup Menu Setup Time The Setup Time key activates the clock calendar sub menu The time and date are used to label all screen prints and plots as well as disk files This menu is used to check or change the time and date Time og 10 23 Date 10 1 89 Return Tim
160. ommand sets or reads the RS232 plotter baud rate The pa rameter i ranges from 0 to 4 and selects baud rates of 300 0 1200 1 2400 2 4800 3 and 9600 4 This baud rate should match the baud rate of the plotter in use The PLTA command sets or reads the GPIB plotter address The param eter i ranges from 0 to 30 and should agree with the address of the plot ter in use The PLTS command sets or reads the plot speed If i 0 fast plot speed is used if i21 slow plot speed is used The PNTR command sets or reads the trace pen number The pen num ber is in the range of 1 to 6 The PNGD command sets or reads the grid pen number The pen num ber is in the range of 1 to 6 The PNAP command sets or reads the alphanumeric pen number The pen number is in the range of 1 to 6 85 Remote Programming PNCR i PNFT i PRNT i The PNCR command sets or reads the cursor pen number The pen number is in the range of 1 to 6 The PNFT command sets or reads the fit pen number The pen number is in the range of 1 to 6 The PRNT command sets or reads the printer type The printer type may be EPSON i20 or HP i 1 SAVE AND RECALL FILE COMMANDS When using file commands the status byte should be queried after the command is sent to check if the com mand generated an error Common sources of errors are file not on disk no space on disk and no disk in drive For example the command line SVTR ERRS lt will save
161. on Cable Assembly Ribbon Connector Female Switch Panel Mount Power Rocker SOFTPOT Thermostat Trim Pot Cond Plastic PC Mount Thermistor ICL Inrush Current Limiter Transformer Misc Components Ferrite Beads Fabricated Part Machined Part Injection Molded Plastic Injection Molded Plastic Keypad Conductive Rubber Fabricated Part Rear Panel Fabricated Part Fabricated Part Fabricated Part Machined Part Fabricated Part Lexan Overlay Fabricated Part Fabricated Part Printed Circuit Board Fabricated Part Fabricated Part Fabricated Part Poari 15 EEEEEEREILLILIIIGUGULIIIIULLLLIUIILILIUILI LCLHULCI ILILLLUUULLLL JLL eLUU U Gc GQ CGQBGSLOOOOOA GEOUL LOA SL 7 00473 720 8 00034 850 8 00040 840 9 00267 917 Sa REF SRS part U 301 3 00345 342 U 302 3 00345 342 U 303 3 00345 342 U 304 3 00345 342 20 0 00159 000 20 0 00179 000 20 0 00180 000 20 0 00185 021 20 0 00204 000 20 0 00223 029 20 0 00248 026 20 0 00259 021 20 0 00315 021 20 7 00147 720 20 7 00394 720 20 7 00395 720 SR770 27 28 29 FLOPPY 7 Z AXIS GENERIC VALUE 64KX8 120 64KX8 120 64KX8 120 64KX8 120 FAN GUARD RIGHT FOOT LEFT FOOT 6 32X3 8PP REAR FOOT 6 32X3 8TR PH 10 32X3 8TRUSSP 4 40X1 2 PP 6 32X7 16 PP BAIL SR770 6 SR770 7 MISCELLANEOUS M 144 Fabricated Part Disk Drive CRT Display Product Labels DESCRIPTION EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM
162. oprocessor System 116 Keypad Interface 116 Keyboard Interface 116 Spin Knob 117 Speaker 117 Clock Calendar 117 SAFETY AND PREPARATION FOR USE WARNING Dangerous voltages capable of causing injury or death are present in this instrument Use extreme caution whenever the instru ment covers are removed Do not remove the covers while the unit is plugged into a live outlet CAUTION This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR set for the wrong ac line voltage or if the wrong fuse is in stalled LINE VOLTAGE SELECTION The SR430 operates from a 100V 120V 220V or 240V nominal ac power source having a line fre quency of 50 or 60 Hz Before connecting the pow er cord to a power source verify that the LINE VOLTAGE SELECTOR card located in the rear panel fuse holder is set so that the correct ac in put voltage value is visible Conversion to other ac input voltages requires a change in the fuse holder voltage card position and fuse value Disconnect the power cord open the fuse holder cover door and rotate the fuse pull lever to remove the fuse Remove the small print ed circuit board and select the operating voltage by orienting the printed circuit board to position the desired voltage to be visible when pushed firmly into its slot Rotate the fuse pull lever back into its normal position and insert the correct fuse into the fuse holder LINE FUSE Verify that the correct line fuse is ins
163. pacitor Ceramic 50V 80 20 Z5U AX C207 5 00002 501 100P Capacitor Ceramic Disc 50V 1096 SL C208 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C209 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C210 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 211 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 212 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 213 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 214 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 215 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C 216 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad C217 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 ZBU AX C218 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C219 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C220 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 133 art List C 221 C 301 C 302 C 303 C 304 C 305 C 306 C 307 C 308 C 309 C 310 C 311 C 312 C 313 C 314 C 315 C 401 C 402 C 501 C 502 C 601 C 602 C 701 C 702 C 703 C 704 C 1501 CX403 D 101 D 102 D 103 D 104 D 105 D 201 D 202 D 203 D 204 D 301 D 701 JP1601 JP1602 JP1603 L 201 L 301 L 302 L 303 N 201 N 202 N 203 N 301 N 302 N 303 N 304 N 305 N 401 5 00012 501 5 00225 548 5 00237 523 5 00238 523 5 00151 501 5 00151 501 5 00065 513 5 00060 512 5 00225 548 5 00225 548 5 00225 548 5
164. perations The resolution of the display is 640H by 480V The brightness is adjusted using the brightness control knob located at the upper left corner As with most video displays do not set the brightness higher than necessary The display may be adjusted left and right using the Setup Screen function in the SETUP menu FRONT PANEL OVERVIEW 15 Front Panel BNC Connectors The main area of the display is occupied by the data display Data is graphed as accumulated counts per bin on the vertical axis and bin or time from trigger on the horizontal axis The graph is continuously updated during data acquisition When data acquisition is DONE the total accumu lated data is displayed A complete description of the screen display fol lows in the next section SOFT KEYS The SR430 has a menu driven user interface The 6 soft keys to the right of the video display have different functions depending upon the information displayed in the menu boxes at the right of the vid eo display In general the soft keys have two uses The first is to toggle a feature on and off or to choose between 2 settings The second is to highlight a parameter which is then changed using the spin knob or numeric keypad In both cases the soft keys affect the parameters which are dis played adjacent to them Guide To Operation KEYPAD The keypad consists of four groups of keys The ENTRY keys are used to enter numeric parame ters which have been
165. pulsed discharges it is difficult to reduce the noise on any coax cable be low a few millivolts A good wide bandwidth pre amplifier such as the SR430 will have about 1 5 nV per root Hertz or about 25 uV rms over its 250 MHz bandwidth Peak noise will be about 2 5 times the rms noise and so it is important that the PMT provide pulses of at least 100 uV amplitude Use manufacturer s specifications for the current gain and risetime to estimate the pulse amplitude from the PMT Amplitude mV 4 x Gain in millions Risetime in ns This formula assumes that the electrons will enter a 50 Ohm load in a square pulse whose duration is twice the risetime Since the risetime will be lim ited to 1 2 ns by the 300 MHz bandwidth of the preamplifier do not use risetimes less than 1 5 ns in this formula The current gain of a PMT is a strong function of the high voltage applied to the PMT Very often PMT s will be operated well above the high voltage recommended by the manufacturer and so at sub stantially higher current gains 10x to 100x above specs There are usually no detrimental affects to the PMT so long as the anode currents are kept well below their rated values Conclusions Select a PMT with a risetime 3 ns and a current gain 5 million DARK COUNTS PMT s are the quietest detectors available The primary noise source is thermionic emission of electrons from the photocathode and from the first few dynodes of t
166. r data points a too wide bin may overload before expected 5 The bin clock source is set to External In this case the EXT BIN CLK input controls the bin tim ing If there is no input to the EXT BIN CLK there will be no bins 6 Accumulation mode incorrect Check that the ac cumulation is not toggling or externally controlled If accumulation is set to external check that the SUBTRACT input is receiving a valid TTL signal at the correct time 7 Accumulation is inhibited If the INHIBIT input is being driven accumulation may be inhibited In this case no records accumulate CALIBRATION Most of the calibration parameters are determined by a computer aided calibration procedure after burn in at the factory These calibration parame ters are stored in the permanent memory of each unit The calibration mainly involves setting the an alog thresholds and levels accurately This section details the calibration of the signal in puts which because of their high speed require some hand adjustment In addition the repair pro cedure for the signal inputs is discussed CAUTION See the diagram at the beginning of the circuit description to locate the circuit boards inside the chassis ALWAYS disconnect the power cord and wait at least two minutes before opening the unit Dangerous power supply voltages may be present even after the unit has been unplugged Check the LED at the front edge of the power supply board The unit
167. ration SUB TOGGLE or EXTERNAL accumulate mode The overflowed bin s will stay at the limit ing value while non overflowed bins continue to accumulate normally ERR Flashes whenever there is a computer interface error such as illegal command or out of range pa rameter is received This does not flash for a print er or plotter error Act Flashes when there is activity on the computer in terfaces This does not flash for printer or plotter activity SRQ This indicator turns on when a GPIB Service Re quest is generated by the SR430 SRQ stays on until a serial poll of the SR430 is completed REM This indicator is on when the front panel is locked out by a computer interface No front panel adjust ments may be made To return the unit to local control if allowed press the HELP key Guide To Operation 20 CONTROL START STOP CURSOR AUTO RESET SCALE D aua aun G H J M N FC EE S T U V Y Z NORMAL AND ALTERNATE KEYS The normal key definitions are printed on each key In addition each key also has an alternate definition printed below it The ALT key toggles the keypad between the two definitions The ALT screen indicator is on when the alternate defini tions are in use The ALT and ENTER keys have the same definition in both modes The alter nate keys should only be used when accessing files on the disk drive START STOP AND RESET The START a
168. re not supported All file ac cess is to the root directory The STAT command starts the statistical calculations Only the data with in the region specified by the LLIM and RLIM limits is analyzed Use stat us byte query to detect when the statistical calculation is done If the STAT command is used before the LLIM and RLIM commands have set the limits the results are invalid and an execution error may result The SPAR i command queries the results of a statistical calculation If no STAT command has been done the SPAR command returns invalid data The STAT command calculates the mean standard deviation total area and the baseline area for the data within the limits set by LLIM and RLIM see the Math menu section of this manual The parameter i in the SPAR i command selects the parameter to read The value of i from 0 to 3 selects mean standard deviation total area and baseline area 88 Remote Programming PRINT AND PLOT COMMANDS When using the print or plot commands the status bytes should be queried after the command is sent to check if the command generated an error Common sources of errors are printer plotter not connected and printer plotter interface incorrectly configured For example the command line PALL ERRS lt lf gt will plot the screen and return the Error Status Byte when finished The Plot Error bit may be checked to make sure that the PALL command terminated without error Be sure that the printer or plot
169. recog nized Pressing START will continue the data ac Guide To Operation quisition and pressing STOP will reset the unit to the CLEAR state Pressing STOP while in the PAUSE or DONE states will reset the unit to the CLEAR condition All data accumulated will be lost and reset to zero In general pressing the STOP key twice in suc cession will put the unit in the CLEAR condition IMPORTANT NOTE Data which is cleared can not be recovered Be sure to save valuable data to the disk to avoid accidentally erasing it MENU KEYS All operating parameters of the SR430 are grouped into ten function menus The ten menu keys select which menu of parameters is dis played next to the six soft keys The soft keys then either toggle a parameter highlight a parameter entry field for numeric entry or knob adjustment or display a submenu The LEVELS menu displays the trigger discrimi nator and auxiliary D A levels The MODE menu displays the bin width bins per record records per scan accumulation mode and trigger offset The DISPLAY menu shows graph translation and zoom and the cursor modes The SETUP menu configures the computer interfaces sound real time clock plotter and printer The SAVE and RECALL menus are the disk menus Data set tings LEVELS and MODE and system setups may be saved and recalled from disk The MATH menu analyzes and manipulates data Smoothing curve fitting statistical ana
170. rigger Offset This key is activated only when the Bin Clock Source is Internal Press ing this key will activate the internal bin width entry field The bin width may only be adjusted using the knob The available bin widths are 5ns 40ns 80ns 160 ns 10 486ms 10ns and 20ns bins are not available The Bins Record key allows the knob to change the number of bins per record Numeric entry is not allowed in this field The number of bins per record is set in 1k 1024 increments from 1k 1024 to 16k 16 384 This represents the maximum number of bins which can be displayed and analyzed at one time This limitation is due to the data display buffer having a maximum capacity of 16k data points The data acquisition memory however can store up to 32 704 data points Up to 32 704 bins may actually be acquired and accumulated of which up to 16k bins may be displayed at one time The Trigger Offset determines how many bins are skipped at the beginning of the total record before data is transferred to the display buffer A simple memory map is shown below Data Acquisition Memory 32704 Total Acquired Data Trigger Offset Bins Record 0to 16320 1024 to 16384 Display Memory equal to Bins Record This key activates the Records per Scan entry field Both numeric entry and knob adjustment are allowed The Records Scan is the number of records which will be accumulated before the data acquisition is DONE The Records Scan may be p
171. rint the screen Same as PRINT key Plot the entire screen Plot the trace only Plot the cursor only DATA ACQUISITION CONTROL SSCN Start data acquisition Same as START key PAUS Pause a scan in progress Same as STOP key while BUSY CLRS Reset the data memory Same as STOP key while DONE SCAN Query the number of records which have been accumulated so far DATA TRANSFER BINA i Read the entire data record in ASCII format If i included read only bin i data BINB Read the entire data record in binary format INTERFACE RST Reset the unit to its default configurations Read the SR430 device identification string LOCL i Set the Local Remote state to LOCAL 0 REMOTE 1 or LOCAL LOCKOUT 2 STATUS CLS Clear all status registers ESE i Set the Standard Status Byte Enable Register to the decimal value i 0 255 ESR i Query the value of the Standard Status Byte If i is included only bit i is queried SRE i Set the Serial Poll Enable Register to the decimal value i 0 255 STB i Query the value of the Serial Poll Status Byte If i is included only bit i is queried PSC i Set the value of the Power On Status Clear bit to Set 1 or Clear 0 ERRE i Set the Error Status Enable Register to the decimal value i 0 255 ERRS i Query the value of the Error Status Byte If i is included only bit i is queried MCSE i Set the MCS Status Enable Register to the decim
172. rogrammed from 0 to 65 535 When set to 0 accumulation will continue indefinitely until the STOP key is pressed This mode of operation is useful when setting up an experiment since the BIN CLK OUT and SYNC BUSY out will both be active indefinitely in stead of only until the scan is DONE The Records Scan may be changed while data acquisition is in progress If the new value is less than the present number of records accumulated the scan will finish with the next record If the new value is greater then accumulation progresses normally until the new number of records has been acquired The Trigger Offset determines how many bins are skipped at the begin ning of the total record before data is transferred to the display buffer Up to 32 704 bins may actually be acquired and accumulated but only a maximum of 16k bins may be displayed at one time The actual number of bins which are stored in the data acquisition memory is equal to Trig ger Offset plus Bins Record with a maximum of 32 704 30 More Accumulate Add xt Accumulate Mode Mode Menu The Trigger Offset entry field accepts numeric entry or knob adjustments The resolution is 16 bins and the limit is 16 320 bins Below the entry field the actual time corresponding to the trigger offset is displayed This is simply the Trigger Offset in bins multiplied by the bin width The Trigger Offset is used when the data of interest occurs long after the trigger and short
173. rogramming DATA TRANSFER COMMANDS BINA i BINB The BINA query reads the display memory record data in ASCII format If the parameter i is included only the value of the data in bin i is re turned The first bin is i 0 and the last bin is i bins record 1 If the pa rameter i is omitted then the entire record of data is returned In this case data is sent continuously starting with bin 0 and ending with the last bin in the record bins record 1 Each data point is separated by a comma and the last data point is followed by a line feed GPIB or car riage return RS232 This format is convenient when using DMA driven host interfaces If BINA is used to transfer the entire record over the RS232 interface the host computer interface should be interrupt driven or have fast data communication routines since the data transmission is limited only by the baud rate If BINA is used to transfer the entire record while the unit is BUSY and a scan is in progress the entire record will be transferred before the dis play memory buffer is updated The data acquisition memory will contin ue to acquire data at the trigger rate and will be transferred to the display buffer when the BINA transfer is complete The BINB query reads the entire display memory data record in binary format over the GPIB interface The BINB command is not available over the RS232 interface The BINB command may only be used if the data is integer count data
174. rs and interrupts the pro cessor to start accumulating the data in the fast buffers The address counter has 16 bits with b3 missing B15 is reserved to signal done so only 14 bits re main active However the clock LATCH ODD comes every 2 bins an even and an odd the maximum number of bins in a record can be 2 15 or 32 768 The counter output bits are the address bits for the even fast buffers U912 and U913 latch the address for the odd fast buffers since the odd buffers write while the buffer is being clocked All address logic uses FAST parts since a new ad dress can be required every 80 ns After the record has been acquired the data will be read out and accumulated into an accumulation memory During accumulation the 16 MHz oscilla tor U901 generates the address clocks Before accumulation the address counters are reloaded with the bins record divided by 2 U902 divides the 16 MHz by 4 and U905B divides by 2 so the ad dress is clocked at 2 MHz Each address repre sents 2 data points an even and an odd The con trol line START ACC begins accumulation Accumulation proceeds at 250 ns per point until Circuit Description the DONE signal becomes active DONE inter rupts the processor to rearm the trigger to acquire the next record ACCUMULATOR U1012 and U1013 are 32kbyte accumulation RAMs U1012 is the lower 8 bits and U1013 is the upper 8 bits The address to these RAMs comes from the fast buffer address counter
175. rsor mode Note that cursor movement is activated by the CURSOR key and not by this menu DISPLAY Translate The Translate key will activate knob control of graph translation in either the vertical or horizontal direction When the Translate key is pressed the currently selected direction will become highlighted and the knob will now translate the graph in that direction Pressing the Translate key again will toggle to the other axis Horizontal translation is in increments or 1 100 of the screen width round ed up to the nearest integer number of bins Translation below bin 0 or past the last bin is not allowed Vertical translation is in increments of 1 10 of a division or 1 count whichever is larger If the data is in floating point representation as a result of a Math function then translation is in incre ments of 1 10 of a division The Zoom key will activate knob control of graph scaling in either the ver tical or horizontal direction When the Zoom key is pressed the currently selected direction will become highlighted and the knob will now expand the graph in that axis Pressing the Zoom key again will toggle to the oth er axis Vertical scaling is in a 1 2 5 10 sequence starting with 1 count division 35 Display Menu Cursor On Off Cursor Width Cursor Seeks Grid On Off and going up to 5000 counts division 40000 counts full scale This al lows the full range of count data to be displayed I
176. s small as 5 12 us are to be seen then the bin width should be 5 12 us 4k bins record or smaller If resolution is not required use a wider bin width In this exam ple 20 48 us is the widest bin which will still allow a record time of 20 9 ms due to the 1k minimum record length Why not always use the narrowest bin for the best resolution One reason is that the data record has many more points Many functions such as scal ing fitting calculations etc will take longer to per form on longer data records Another reason is that each individual bin will have a smaller number of counts Because statistical count noise is equal to the square root of the count the signal to noise ratio of each bin will be worse If wide features are being curve fit then the many bins does not de grade the data since there are the same number of total counts as the fewer bins record In this case smoothing can be used to reduce the noise and the resolution Why not always use the widest bin for the best sig nal to noise in each bin and the fastest processing time One reason is that since the data in each bin will be larger the bins may overflow sooner When data overflows then the bin width needs to be reduced so that more bins split up the large data points Another reason is that wide bins mean less resolution when measuring narrow features When curve fitting over a small number of bins the fit may be less accurate Thus choosing the comb
177. sed to ignore a record If INHIBIT is TTL high when the trigger is received that record is ignored and not accumulat ed The record does count towards the number of records accumulated AUX 1 AUX 2 The rear panel AUX 1 and AUX 2 outputs are pro grammable general purpose dc analog outputs The output voltages may be set from the front pan el or computer interface and can range from 10V to 10V These outputs may be used wherever an external variable dc voltage is required TEST The rear panel TEST output is a 50 NIM level output The output frequency is 50 MHz and is synchronous with the BIN CLK The TEST output is used to test that the counter and accumulator are working properly By connecting the TEST out put to the SIGNAL input a known number of counts can be put into every time bin This allows the user to quickly check the functionality of the unit DISK DRIVE The 3 5 disk drive is used to save data setups and configurations The format is DOS compatible and the capacity is 720k COMPUTER INTERFACES RS232 and GPIB IEEE 488 interfaces are stan dard on the SR430 All settings of the instrument may be controlled via the computer interfaces Data may also be transmitted to a computer PLOTTING An HPGL compatible plotter may also be connect 14 ed directly connected to the RS232 or GPIB inter face Data will be plotted directly from the SR430 without a computer PRINTER A parallel printer port is st
178. selects the output level of the AUX 1 output as the active entry field A new output level may be entered from the numeric keypad in units of Volts or the knob may be used to adjust the present level The output level is adjustable from 10 000V to 10 000V with 5mV resolution The Aux 2 Level key selects the output level of the AUX 2 output as the active entry field A new output level may be entered from the numeric keypad in units of Volts or the knob may be used to adjust the present level The output level is adjustable from 10 000V to 10 000V with 5mV resolution 28 MODE MENU Introduction The Mode menu sets up the data acquisition parameters including bin width accumulation mode bins per record and records per scan With the exception of the Records Scan and the ReAcquire Offset these pa rameters may not be changed unless the unit is in the CLEAR state Re Acquire may only be performed when data acquisition is done in Clk Src MODE nternal Bin Width Bin Clock Source Internal Externa TT terna Internal Bin Width Bins Record Records Scan Trigger Offset More Accumulate Mode Toggle Toggle Count Pause at Toggle ReAcquire From Offset Return Bin Clock Source This key toggles the time base of the time bins from internal clock to ex ternal bin clock When set to External the EXT BIN CLK input deter mines the width of each bin 29 Mode Menu Bin Width Bins Record Records Scan T
179. set the limits the results are invalid and an execution error may result The FITS command uses the limits set by LLIM and RLIM and not the front panel limits Conversely the front panel Do Fit function uses the on screen limits and not the LLIM and RLIM limits Using the View Parameters function will display the most recent fit parameters whether the fit was performed from the front panel or from the computer interface The PARS i command queries the fit parameters after a curve fit has been performed If no fit has been done or the selected parameter is un used in the fit the PARS command returns invalid data The curve fit parameters are 10 a b and c see the Math menu section of this manu al The parameter i in the PARS i command selects a fit parameter to read The value of i from 0 to 3 selects 10 a b and c The LLIM command sets or reads the left limit of the curve fit region The parameter i is the bin of the record which is the left limit Unlike the lim its set by the cursor from the front panel which must be on the graph the LLIM command can set the limit at any bin within the record The parameter i must be in the range 0 lt i lt number of bins per record and i must be less than the right limit set by RLIM The RLIM command sets or reads the right limit of the curve fit region The parameter i is the bin of the record which is the right limit Unlike the limits set by the cursor from the front panel which
180. sistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 art 15 EEEEEEREILLLLLUIIIIUIIIIIIIULLUIIILILLUIIUILI INIITETgLTITCLLL I3 G S amp AIUUUOCGHLDN PG U DLIUAAGAA OAoOoO o UP c G O OL UG O O4 R 405 R 406 R 407 R 408 R 409 R 501 R 502 R 601 R 602 U 101 U 102 U 201 U 202 U 203 U 204 U 205 U 301 U 302 U 303 U 304 U 305 U 306 U 307 U 308 U 309 U 310 U 311 U 312 U 313 U 314 U 401 U 402 U 403 U 404 U 405 U 406 U 407 U 408 U 409 U 410 U 411 U 412 U 413 U 414 U 501 U 503 U 504 U 505 U 506 U 507 U 508 U 509 U 511 U 512 U 513 4 00027 401 4 00021 401 4 00103 401 4 00031 401 4 00086 401 4 00471 401 4 00041 401 4 00471 401 4 00041 401 3 00106 340 3 00106 340 3 00091 340 3 00294 340 3 00294 340 3 00294 340 3 00180 340 3 00266 340 3 00554 340 3 00359 340 3 00160 340 3 00090 340 3 00171 340 6 00071 621 3 00206 340 3 00194 340 3 00194 340 3 00194 340 3 00194 340 3 00194 340 3 00359 340 3 00206 340 3 00194 340 3 00194 340 3 00194 340 3 00194 340 3 00194 340 3 00208 340 3 00269 340 3 00269 340 3 00357 340 3 00359 340 3 00358 340 3 00359 340 3 00194 340 3 00194 340 3 00359 340 3 00238 340 3 00207 340 3 00466 340 3 00466 340 3 00467 340 3 00400 340 3 00406 340 3 00356 340 3 00180 340 150 LT1007 LT1007 LF412 AD96685 AD96685
181. sk drive The file format is described in the Remote Programming sec tion Save Trace ECON Save Settings ss Save Settings Save 1 System Save System Utilities Catalog On Off Disk Utilities Format Disk Save Keys Each Save Key activates a sub menu The Save Trace Settings and System menus are similar 47 Save Menu Save Trace File Name TEST DAT Catalog Off Return The Save Trace sub menu is used to save the data record and the graph scaling parameters The parameters specified in the Mode menu are also saved in the trace file since the data would be meaningless without them Save Trace File Name Catalog On Off TEST Pressing this key will save the current display memory data and scaling parameters to the file specified in the File Name field This key activates the File Name entry field File names are entered using the keypad and alternate keypad The ALT key allows letters to be entered DOS file name conventions must be followed i e file names are 8 char acters or less with an extension of up to 3 characters ABCDEFGH XYZ is a valid file name DOS sub directories are not supported All files are saved to the root directory This key toggles the file catalog display screen on and off The file catalog display lists all files currently in the root directory A sample catalog screen is shown below The first file will be highlighted and the file
182. smooth the data with the corresponding 21 pt width A width of 25 points means that features which span less than 25 17 pt bins will be smoothed out The time displayed in each menu box is the 11 pt smoothing width multiplied by the bin width and represents the real time i smoothing width 5 pt All of the data record in the display memory is smoothed regardless of the graph display While calculations are in progress the Calculating message is displayed below the graph Smoothing may be repeated until the desired noise reduction is attained Return The Return key will return to the main Math menu 60 Fit Doft View Params L Left Limit O Right Limit C Return L Type of Fit DoFit View Parameters Math Menu The Fit sub menu allows the user to fit one of three curves to the dis played data lines exponentials and Gaussians Fitting is done using the Marquardt Gradient expansion algorithm to minimize chi squared Type of Fit This function toggles the Type of Fit between line exponential and Gaussian The fit takes place only within the fit region defined by the Left and Right Limits see below Pressing this key starts the actual fitting calculations As each pass of the fitting routine progresses the pass number and current value of chi squared is displayed The algorithm is designed to terminate when the change in chi squared falls below 0 195 although the fit may
183. specifications This key displays information about Stanford Research Systems Inc This key displays information about the use of the SR430 This key displays a list of the remote commands available This key displays an explanation of the remote programming status bytes This key displays a table of fundamental constants 73 Info Menu 74 INSTRUMENT SETUPS DEFAULT SETUP POWER ON CLEAR If the CLR key is held down when the power is turned on the instrument settings will be set to the defaults shown below instead of the settings in effect when the power was turned off Menu Item Trigger Level Trigger Slope Discriminator Level Discriminator Slope Aux 1 Level Aux 2 Level Bin Clock Source Bin Width Bins Record Records Scan Trigger Offset Accumulate Mode Toggle Count Pause At Toggle From Offset Cursor Cursor Width Cursor Seeks Grid Output To RS232 Baud Rate RS232 Word Length Setting 100 mV Positive 10 0 mV Negative 0 0 V 0 0 V Internal 5 ns 1k 1000 0 Add 1 No 0 On Wide Maximum On GPIB 9600 8 bits Menu Item RS232 Parity GPIB Address Overide Remote Key Click Alarms Plot Mode Plotter Baud Rate Plotter Address Plot Speed Trace Pen Grid Pen Alpha Pen Cursor Pen Fit Pen Printer Type File Name Type of Fit Operation Argument Type Argument Status Enable Registers Setting None 8 No On On RS232 9600 1 Fast 1 o
184. stor is Q3 The base of this transistor is controlled so that the emitter will pro vide a low impedance source of 5 VDC The cur rent gain of Q3 remains large until the collector emitter voltage drops to about 0 4 VDC hence the low drop out voltage of the regulator The base of Q3 is driven by the emitter of Q6 which is driven by the output of the op amp U3B By comparing the output of the regulator to the 5 00V reference the op amp maintains the regulator s output at 5 00 VDC The current output from the regulator is measured by the 0 1 resistance of fuse F1 If the current exceeds about 2 Amps then the output of U3A turns on pulling the sense input of U3B high thereby turning off the regulator s output U7 and U11 are regulators for 15 VDC U8 sens es the output voltages and compares them to the reference to control the adjust pin of the regula tors U13 and U15 are the 12V regulators Since these supplies do not need to be accurate output sens ing is not used instead the 15V outputs are used to set the output levels U10 and U12 provide unswitched 15V sources These voltages are on whenever the unit is plugged into an AC power source U2 provides power up reset and U1A provides power down reset The 24 VDC brushless fan speed is controlled by the temperature in the box The warmer the box the faster the fan turns When cool the 10 mA drawn by R5 through R4 is not sufficient to turn on Q2 As the box warms above
185. sub menu will smooth the data in the display memory using the Savitsky Golay algorithm For details on the Savitsky Golay smooth ing technique see Abraham Savitsky and Marcel J E Golay Smooth ing and Differentiation of Data by Simplified Least Squares Procedures Analytical Chemistry 36 8 July 1964 In essence smoothing removes features which are narrower than the number of smoothing points Smoothing is performed on the entire data record in display memory re gardless of graph scaling Smoothing the data will change the data from integer count data into single precision 16 bits floating point representa tion Any calculation which requires a greater range will either underflow return zero or overflow An operation which overflows will display an er ror message and abort Smoothing alters the data in the display memory Original unsmoothed integer data may be recalled using the ReAcquire function in the Mode 59 Math Menu menu Once smoothed the data remains in floating point form even when the Smooth menu is exited If floating point data is saved to disk using the Save Trace function it will be recalled as floating point data us ing Recall Trace To avoid accidentally losing original data save the count data to a disk file before performing Smooth menu opera tions 235p O 256 usec 2ipt O 215 usec 17pt O 174 usec 11pt O 113 usec 5 pt L 51 2 usec Return 25 pt Pressing a smoothing key will
186. t and TS1 is a thermal switch which will interrupt the AC line if the heat sink tempera ture rises to 50 C Bridge rectifiers are used to provide unregulated DC at 22V 18V 8V and 4V Schottky diodes are used for all supplies except the 22V in order to reduce rectifier losses The comparator U2C provides a square wave line crossing signal Resistors provide a bleed current on all of the un regulated supply filter capacitors Because of the large capacitances in this circuit the time for the voltages to bleed to zero is about a minute after the power cord is removed Note that the AC power source must be re moved in order to discharge the unregulated supplies POWER SUPPLY REGULATORS The voltage regulators provide outputs at 5V 5 2V 2V 15V and 12V The low voltage regu lators 5V and 2V are designed to operate with a very low drop out voltage U9 is a precision 5 00V reference which is used to 118 set all of the output voltages This provides very accurate power supply outputs The power switch simply switches the power to U9 When U9 is off the reference voltage is removed and the regula tors drop to zero volts There are 2 5V supplies one to power the CPU board and disk drive 5V_P and one to power the ECL and TTL data acquisition boards 5V_1 The following description refers to the 5V_P sup ply but describes the 5V_I 5 2V and 2V sup plies as well The main pass transi
187. t at the output of U602A The processor keeps track of the knob s position continuously SPEAKER The speaker is driven by a timer on the 800186 The timer outputs a square wave which is enabled by U602B and drives the speaker through Q705 CLOCK CALENDAR U702 is an MC146818 real time clock chip which keeps track of time and date The time base is a 32 768 kHz oscillator made by U706 Both U702 and U706 are battery backed up PRINTER INTERFACE The printer interface allows screen displays to be printed to Epson compatible printers Output data is buffered by U703 an LS octal latch Output con trol bits are buffered by the open collector driver U704 and input control bits are discriminated by U705C and U705D VIDEO GRAPHICS INTERFACE The video graphics interface is centered around U810 an HD63484 graphics controller The HD63484 generates the video sync signals con trols the video memory and draws graphic primi tives such as lines circles polygons etc and oth er high level functions The HD63484 relieves the 80C186 from having to calculate each video image and greatly increases display speed U813 and U814 are 32kbyte RAMs which make up the 64k video memory The video screen is 640H by 480V and requires 38 400 bytes of memory The remaining memory is used to store patterns fonts and other graphic objects The data and ad dress are multiplexed and U811 and U182 are the address latches Data is read 16 bits at
188. t impedance is 10 K and the minimum pulse width is 10 ns The trigger level is adjustable from 2V to 2V with either slope The minimum pulse amplitude is 100 mV SYNC BUSY TTL output high whenever the SR430 is acquiring or accumulating a record Triggers received during this time are ignored The rising edge of SYNC BUSY is synchronous with the start of the first bin and may be used to trigger the experiment to re move the 2 5 ns uncertainty between trigger and SYNC BUSY This output is active only when the SR430 is in the BUSY state actively accumulating records SIGNAL INPUT The SIGNAL INPUT is a 50 analog input A pho tomultiplier or preamplifier output is connected to this input The input is linear between 300 mV to 300 mV and protected to 5 Vdc DISC OUT The DISC output is a 50 NIM level output is ac tive low 0 7 V when the signal input exceeds the threshold level with the correct slope Counting oc curs on the falling edge BIN CLK OUT The BIN CLK output is a 50 NIM level output showing the position of the time bins Each transi tion of this output is a bin boundary This output is active only when SYNC BUSY is active EXT BIN CLK INPUT The EXT BIN CLK is a TTL input whose rising edges mark the bin boundaries The maximum clock rate is 4 MHZ This input is active if the bin width has been programmed to EXTERNAL OPTION This connector is unused Guide To Operation SCREEN DISPLAY Cursor Posit
189. t is cleared no data in memory If the unit is BUSY or DONE with data acquisition the mode menu parameters with the exception of ROFF are not adjustable An execution error is generated if a Mode Control Command which attempts to change a mode parameter is received during BUSY PAUSE or DONE states Use the serial poll status byte to determine if the SR430 is CLEAR BCLK i The BCLK command sets or reads the bin clock time base The parame ter i 0 selects internal while i 1 selects external When set to external the EXT BIN CLK input determines the width of each bin BWTH i The BWTH command selects the internal time base bin width The pa rameter i selects a bin width as shown below i bin width i bin width 0 5 ns 10 20 48 us 1 40 ns 11 40 96 us 2 80 ns 12 81 92 us 3 160 ns 13 163 84 us 4 320 ns 14 327 68 us 5 640 ns 15 655 36 us 6 1 28 us 16 1 3107 ms 7 2 56 us 17 2 6214 ms 8 5 12 us 18 5 2429 ms 9 10 24 us 19 10 486 ms BREC i The BREC command sets or reads the bins per record The record length is programmed in 1k 1024 steps The parameter i is an integer from 1 to 16 If the parameter i21 the record length is 1k 1024 If i22 the record length is 2k 2048 and so on The maximum value of i is 16 for a maximum record length of 16k 16 384 RSCN i The RSCN command sets or reads the records per scan The records per scan is the number of records which will be accumulated The records scan may be progr
190. t is the number of records accumulated in one mode add or subtract before switching to the opposite mode For example if the Tog gle Count equals 4 then the first 4 records are added the next 4 records are subtracted the next 4 are added etc until the scan is complete In general the Toggle count should be set so that a complete scan has an equal number of records added and subtracted If the Toggle Count is greater than the Records Scan then all records will be added but the maximum accumulation per bin will still be 16 383 This key is active only if the Accumulate Mode is set to Toggle If Yes is selected then data acquisition pauses whenever the accumulate mode toggles between add and subtract This is useful if the experiment takes time to change modes Use the START key to continue data acquisi tion If No is selected data acquisition runs without pause until the scan is completed The ReAcquire key will restore the display buffer with data from the data acquisition memory The total accumulated record of data is always avail able in the data acquisition memory while in the DONE state When the STOP RESET key is used to reset to the CLEAR state all accumulated data is lost The number of bins transferred to the display memory for graphing and analysis is equal to the Bins Record This data may be changed using the MATH menu functions For example the data may be squared multi plied by a constant normalized etc Thes
191. t of U702B are dif ferent then a pulse has been detected and the output of U701C goes high If no other pulses ar rive U701C goes low after the next 200 MHz clock U701C s output is synchronous with the master bin clock and can be sampled at 5 ns inter vals to determine whether a signal pulse arrived during the preceding 5 ns period COUNTERS The even and odd counters are used for 40 ns or greater bin widths They are identical and only the odd counter is described U501A is an ECL flip flop which counts only when the output of U514A is high when clocked The clock input is the 200 MHz master bin clock U514A is high only when the pulse sorter output from U701C is active during the odd gate Be cause the pulse sorter output is synchronous with the 200 MHz clock U501A can sample U514A s output every 5 ns and not miss any pulses Each time a pulse is detected during the odd gate U501A will toggle U501B U504AB are also ECL divide by 2 coun ters U505 is a FAST TTL counter Because the counters are reset before each gate only the first few flip flops are used during the short bins For example in a 40 ns bin only 8 pulses can be de tected so only the first 3 flip flops will toggle Thus the later stages of the counter are used only for longer bins with longer reset times and can be slower counters The last 8 bits of the counter are U506 and U507 which are synchronous HC coun ters The lower 8 bits of count data are latc
192. talled before connecting the line cord For 100V 120V use a 1 Amp fuse and for 220V 240V use a 1 2 Amp fuse LINE CORD The SR430 has a detachable three wire power cord for connection to the power source and to a protective ground The exposed metal parts of the instrument are connected to the outlet ground to protect against electrical shock Always use an outlet which has a properly connected protective ground WARNING REGARDING USE WITH PHOTOMULTIPLIERS The signal inputs may be damaged if a photomulti plier is used improperly with the photon counter When left completely unterminated a PMT will charge a cable to a few hundred Volts in a very short time If this cable is connected to a signal in put the stored charge may damage the front end transistors To avoid this problem provide a leak age path of about 100 K to ground inside the base of the PMT to prevent charge accumulation CONNECTION TO OTHER INSTRUMENTS All front panel BNC shields are connected to the chassis ground and to the power outlet ground via the power cord Do not apply any voltage to either the shields or to the outputs The outputs are not protected against connection to any potential other than ground FURNISHED ACCESSORIES Power Cord Operating Manual ENVIRONMENTAL CONDITIONS OPERATING Temperature 10 C to 40 C Specifications apply over 18 C to 28 C Relative Humidity lt 90 Non condensing NON OPERATING Temperature
193. te is 100 MHz or one count every 10 ns Thus short bins can only acquire a small number of counts per bin in a single record For example if the bin width is 40 ns then a single record can only acquire 4 counts per bin maximum 4 10 ns 40 ns If the bins width is 5 ns then the maximum number of counts per bin is 1 The maximum count capacity of each bin is 32 767 When the bin width is large and the count rate is high it is possible to exceed the count capacity of a bin in a single record In this case the data will overflow and be stored as the maximum count 32 767 A single record can capture a transient counting signal if there are enough counts to be statistically significant in a single shot If the count rate is very low but the signal is repetitive then multiple records may be accumulated Accumulation of records means simply taking each new record and adding it to the sum of all previous records on a bin by bin basis i e data from T4 of each record is summed together data from To of each record is summed together etc Accumulation reduces sta tistical noise since the accumulated counts in each bin will be larger than the data from a single record Each bin can accumulate counts up to 32 767 Additional counts will cause an overflow and the data will be stored as 32 767 If this limit is reached then the bin width should be reduced and the bins per record increased to keep the same record time This will divide th
194. ter has been completely configured before using these commands PRSC The PRSC command will print the currently displayed screen to a printer attached to the rear panel parallel printer port This function is the same as the PRINT key The printer type needs to be configured before using the PRSC command PALL The PALL command generates a plot of the entire screen Each feature uses the assigned Setup Plotter menu PTRC The PTRC command plots only the data trace PCUR The PCUR command plots the cursor markers if the cursor is presently displayed on the screen DATA ACQUISITION CONTROL COMMANDS SSCN The SSCN command has the same effect as pressing the START key The SSCN command only has an effect when the unit is paused or clear PAUS The PAUS command pauses a scan in progress If a scan is not in progress the PAUS command is ignored This is the same as pressing the STOP key while a scan is in progress The unit will be in the PAUSE state CLRS The CLRS command resets the unit to the CLEAR state All data accu mulated will be lost and reset to zero The CLRS command may be used at any time even while a scan is in progress The effect is the same as pressing the STOP key twice in succession SCAN The SCAN query reads the number of records which have been accu mulated so far A host program can use the SCAN query to determine when a scan is finished The status bytes may also be used 89 Remote P
195. th the data save and recall data to disk etc SR430 Multichannel Scaler COMMAND LIST LEVELS TRLV x pato x x x MODE BCLK i BWTH i BREC i RSCN i BOFF i ACMD i TCNT i PTOG i REAC ROFF i DISPLAY AUTS CRPK BUGP CNTR LEFT i BOTM i x HSCL i VSCL i x CURS CURW i CURM GRID i SETUP OUTP i KCLK i ALRM i THRS i TMIN i TSEC i DMTH i DDAY i DYRS i PLTM i PLTB i PLTA i PLTS i PNTR i PNGD i PNAP i PNCR i PNFT i PRNT i Set the Trigger Level to 2 000 lt x lt 2 000 V Set the Trigger Slope to Positive 0 or Negative 1 Set the Discriminator Level to 0 3000 lt x lt 0 3000 V Set the Discriminator Slope to Positive 0 or Negative 1 Set the AUX1 Level to 10 000 lt x lt 10 000 V Set the AUX2 Level to 10 000 lt x lt 10 000 V Set the Bin Clock Source to Internal 0 or External 1 Set the internal Bin Width to 5 ns 0 through 10 486 ms 19 Set the number of Bins Per Record to 1 lt i lt 16 times 1024 Set the number of Records Per Scan to 0 lt i lt 65535 Set the Trigger Offset to 0 lt i lt 16320 in increments of 16 Set the Accumulate Mode to Add 0 Toggle 1 or External 2 Set the Toggle Count to 1 lt i lt 16384 Set the Pause At Toggle mod
196. the cursor marker to the constant argument field above This is convenient when subtracting a baseline or normalizing to a data point If the Argument type is a file then the file selection functions are dis played Pressing the File Name key activates the file name entry field Use the Alternate keypad to enter a file name The file name restrictions are the same as those in the Save and Recall menus This key toggles the file catalog display screen on and off The highlight ed file name will be copied into the File Name entry field Activate the cursor and use the knob to scroll through the file names See the Save or Recall Trace section for a complete description of this function The Return key will return to the main Math menu 65 Math Menu Stats Do Stats Return L The Stats sub menu calculates a variety of statistical information about a display calculation region defined by the Left and Right Limits Left Limit Right Limit Return Do Stats Left and Right Limit Return Pressing this key starts the actual calculation The Calculating mes sage appears below the graph while calculations are in progress For the display region defined by the Left and Right Limits the mean standard deviation total counts and the area under the baseline defined by the two region endpoints are calculated and displayed below the graph Total 8 619800e 004 Mean 3 367109e 002 s o 1 936988 001
197. the data to disk and return the Error Status Byte when finished The Disk Error bit may be checked to make sure that the Save Trace command terminat ed without error FNAM string SVTR SVST SVSS RCTR RCST RCSS The FNAM command sets or reads the active file name All file opera tions use the name specified by the FNAM command Be sure to use the FNAM string command before any file operation commands For example FNAM MYDATA DAT will set the active file name to MYDATA DAT DOS file name conventions must be followed i e file names are 8 characters or less with an optional extension of up to 3 characters Subdirectories are not supported All file access is to the root directory The SVTR command saves the current display memory data settings and scaling parameters to the file specified by the FNAM command The SVST command saves the settings in the Levels and Mode menu to the file specified by the FNAM command The settings represent the hardware configuration of the data acquisition The SVSS command saves the system configuration information in the Setup menu to the file specified by the FNAM command The RCTR command recalls data settings and scaling parameters from the file specified by the FNAM command The RCST command recalls settings information Levels and Mode me nus from the file specified by the FNAM command The RCSS command recalls system configuration parameters Setup menu from the fil
198. threshold with the correct slope a pulse is output at DISC OUT The unit does not have to be actively acquiring data This enables setting the discriminator threshold without triggering the unit TIMING The DISC OUT signal is delayed internally by 20 ns so that the DISC OUT and the BIN CLK output are correct relative to each other In other words a DISC OUT pulse which falls in the first BIN CLK will be counted in the first bin However a DISC OUT pulse is actually due to a signal pulse arriving 20 ns earlier at the SIGNAL INPUT This means that BIN CLK and DISC OUT when viewed on a scope using equal length cables terminated into 50 are accurately timed However for timing purposes each output viewed by itself is 20 ns late relative to the trigger Since the insertion delay for the BIN CLK is 45 ns signal pulses arriving 25 ns after the trigger will be output at the DISC OUT 45 ns after the trigger and counted in the first bin For accurate timing it is best to use DISC OUT and BIN CLK rather than SIGNAL INPUT and BIN CLK since the latter pair are skewed by 20 ns Thus even though the BIN CLK is output with a 45 ns insertion delay relative to the TRIGGER the ac tual insertion delay is 25 ns 20 ns less Signal pulses arriving 25 ns after the TRIGGER will be counted Note that SYNC BUSY and BIN CLK are only out put only during actual data acquisition while the DISC OUT is active all of the time DATA ACQUISITION To be
199. to use The plotter connects to the RS232 or GPIB connector on the rear panel Baud Rate If the Plot Mode is RS232 then the Baud Rate for the plotter may be se Baud Rate lected The baud rate is adjusted using the knob and must match the 9600 ba baud rate of the plotter Plotter Addr If the Plot Mode is GPIB then the Plotter Address must be set The Plot 43 Setup Menu Plotter Addr Plot Speed Define Pens Return ter Address may be entered from the keypad or by using the knob The Plotter Address must agree with the address of the plotter in use This key toggles the Plot Speed Normally when plotting on paper the Fast Plot Speed is used When plotting on transparencies or other non standard media the Slow plot speed may be better Many plotters have a multipen carousel In this case each part of the screen may be plotted using a different color pen The Define Pens key activates a sub menu in which each feature of the screen may be as signed a pen number The allowable pen numbers are from 1 to 6 When using a single pen plotter all features are plotted using the one pen re gardless of the pen definitions Trace Pen This field assigns a pen number to the data trace on the screen Grid Pen This field assigns a pen number to the graph grid Alpha Pen This field assigns a pen number to all of the ic characters on the screen Cursor Pen This field assigns a pen number to the
200. uest is desired every time an event occurs the status bit must be cleared between events STANDARD EVENT bit name usage STATUS BYTE 0 Input Error Set on input queue overflow too many com 92 6 7 Unused Query Error Unused Execution Error Command Error URQ PON Remote Programming mands received at once queues cleared Set on output queue overflow too many re sponses waiting to be transmitted queues cleared Set when a command can not execute correctly or a parameter is out of range Set when an illegal command is received Set by any key press or knob rotation Set by power on The Standard Event status byte is defined by IEEE 488 2 1987 and is used primarily to report errors in com mands received over the communications interfaces The bits in this register remain set until cleared by read ing them or by the CLS command MCS STATUS BYTE E 0 name Triggered Plot Complete Print Complete Toggled Scan Paused Inhibited Unused Unused usage Set when a record is triggered Set when a plot is completed Set when a print screen operation is completed Set when the accumulate mode toggles between add and subtract Set when the unit enters the PAUSE state Set when a record accumulation is inhibited via the rear panel Inhibit input The MCS Status bits stay set until cleared by reading or by the CLS command 93 Remote Programming ERROR STATUS BYTE bit name
201. um 35V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Tantalum 35V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Tantalum 35V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Connector Male Connector Male Connector Male Connector Male Connector Misc Connector Male Right Angle Connector Male Connector Male Connector Male Connector Male Connector Male Connector Male art 15 EEEEEEREELLIULILILUGILIIIIULLULLLILLLIUIULILIIgLTHLELILUELGBH dILMLLOLLGCULSGGSUU A e OL LLOAG4 JP901 JP902 JP903 JP1000 JP1001 JP1002 N 101 N 102 N 501 N 601 N 701 N 801 N 901 N 902 PC1 Q 401 Q 701 Q 702 Q 703 Q 705 R 401 R 402 R 502 R 601 R 602 R 701 R 702 R 703 R 704 R 705 R 706 R 707 R 708 R 709 710 711 R712 R713 R714 R715 R 801 R 802
202. us with the SYNC BUSY out put 1kto 16k in 1k increments 1024 to 32 704 including Trigger Offset 100 MHz 32 767 per bin per trigger 1 to 64k or free run 32 767 per bin in Add mode 16 383 per bin in Toggle or External mode Records may be added or added an subtracted Toggle between add and subtract every N triggers where N is programmable External subtract input may also control the toggle Tp Record time Accumulation time Overhead Number of Bins X Bin Width Number of Bins X 250 ns 150 us SYNC BUSY output is high for Tp after each trigger When SYNC BUSY returns low the next record may be triggered Triggers received while SYNC BUSY is high are ignored Nim level into 50 Low whenever the signal input exceeds the dis criminator level with the correct slope TTL level Rising edge is synchronous with the first time bin of each record Use this edge to trigger the experiment Remains high until re armed for next trigger Nim level into 50 Each transition is a bin boundary Active only while a record is being acquired Timing skew relative to the DISC output is less than 2 ns TTL level Indicates whether the next record will be added to or sub tracted from the accumulation Internal toggle mode 50 MHz Nim output into 50 Use to test counters General purpose analog outputs Full scale 10 VDC Resolution 12 bits 5 mV INPUTS SIGNAL TRIGGER BIN CLK INPUT ACCUMULATOR INHIBIT SUBTRACT
203. ut 20 mV of hysteresis Since the input signal has been amplified by 5 this represents about 4 mV of hysteresis at the input Control signal SIG POL sets the polarity of the output at U205A Q204 and Q205 drive the discriminatory output There is a delay line between the this output and the front panel BNC connector This delay com pensates for the delay in the counter front end Thus DISC output pulses overlap the BIN CLK of the bin in which the pulse is counted U203 is the trigger discriminator It operates like the signal discriminator except that is has about 75 mV of hysteresis and no gain in front of it U204 is the discriminator for the external bin clock input The threshold is fixed at 1 3V to trigger TTL pulses The hysteresis is also about 75 mV 200 MHZ CLOCK AND TRIGGER SYNC U301A is a 200 MHz LC tank oscillator U302 di 119 Circuit Description vides the oscillator output by 64 to provide a 3 125 MHz signal to the phase comparator U304 A 25 MHz crystal oscillator divided by 8 in U306 is the reference signal for U304 The output of the phase comparator is filtered and integrated by U305 to drive the frequency control input of the 200 MHz oscillator D301 The net result is a 200 MHz crys tal based time base available from U301C The discriminated trigger input clocks latch U311A The latched trigger is input to U309A and U309B U309A is clocked by the 200 MHz clock and U309B is clocked by the inverted 200 MHz
204. ve an mean amplitude of 20 mV into 50 Ohms To in crease the pulse height to 100 mV one amplifier in the SR440 preamp provides a gain of 5 with a 300 MHz bandwidth The discriminator threshold is set to 20 mV When viewed with a 300 MHz oscil loscope it is apparent that this threshold setting will count the majority of output pulses but will not count anode rings or amplifier noise SNUBBER 10 RG174 1 4 SR440 APPARATUS FOR DEMONSTRATION EXPERIMENT Typical Experiment The green LED is flashed at a 40 Hz rate for about 1 ms During this time population integrates in the upper level of the laser transition Spontaneous decays from the upper level are counted by the SR430 INSTRUMENT CONFIGURATION The multichannel scaler is triggered by the same pulse which flashes the LED The bin width is 20 48 us and the record length is 1k bins The records per accumulation is set to 100 Thus each record takes approximately 21 ms of real time to acquire which is sufficient to measure the 3 5 ms lifetime of the excited state The pulse rate of 40 Hz will not generate rate errors 100 records will take 2 5 sec to complete DATA ACQUISITION After the SR430 Levels and Mode menus have been setup data acquisition may begin Pressing the START key starts the first record Data accu mulates on the screen until all 100 records have been acquired When data acquisition is DONE the Math menu may be used to fit an exponential curve to
205. y interface the SR430 to a PC via the GPIB interface the instrument interface card and inter face drivers must all be configured properly To configure the SR430 the GPIB address must be set in the SETUP menu The default GPIB address is 8 use this address unless a conflict occurs with other instruments in your system The SR430 will be set to GPIB address 8 whenever a reset is performed power on with the CLR key down Make sure that you follow all the instructions for installing the GPIB card The National Instruments card can not be simply unpacked and put into your computer To configure the card you must set jumpers and switches on the card to set the I O address and interrupt levels You must run the program IBCONF to configure the resident GPIB driver for you GPIB card Please refer to the National Instruments manual for information In the example below the SR430 is installed as a device named mcs Once all the hardware and GPIB drivers are configured use IBIC This terminal emulation program allows you to send commands to the SR430 directly from your computer s keyboard If you cannot talk to the SR430 via IBIC then your programs will not run Use the simple commands provided by National Instruments Use IBWRT and IBRD to write and read from the SR430 After you are familiar with these simple commands you can explore more complex programming commands Binary Transfer Speed The example program uses the BINB binary

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