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Manual - Berkeley Nucleonics Corporation

1. External PM Pk dev 180 deg 1 000 000 0 Hz 10 0 dBm Mh Next Te K t r Ce es Jasa ___ curser ield DTMF Gen SSB Function Pulse KH Mod O 000 OO re ov DTMF Det Sweep FSK Burst Store Hz Joen Randis OOOO Oe m SYNC SIG Power Pwr meas AM FM M Out Dut OO MO De O Arbitrar y XK Sinewave Oth TTL Cmos Zo 50Q Figure 5 7 1 External PM mode display 1 Peak Phase Deviation In this field specify the degree to which the modulating signal is allowed to change the carrier phase You may enter from 0 degrees no change to 180 degrees in 1 degree steps This parameter is a peak value If the deviation value were 180 degrees for example then the output phase will advance to a maximum of 180 degrees and retard to a minimum of 180 degrees for a 1 Vp p input signal To enter a value type 1 to 3 numeric digits If you type 3 digits the value is automatically entered If you only type 1 or 2 digits you can press the MHz key or the KHz key or the Hz key all are equivalent to enter the phase deviation value Note FM modulation is equivalent to PM for small frequency deviation values If you need a larger phase deviation than 180 degrees go to FM mode and specify an appropriate peak frequency deviation value 2 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 3 Level In this field enter the output level
2. PRINT 1 CHRS 5 Print a control E to 625 ASCII char 5 Wait for the 625 to give us some characters When they arrive put then into the string a GOSUB GetResponsel Wait for and get response from 625 to a Allow the user to exit the program by pressing a key IF INKEYS lt gt THEN SYSTEM Exit on first terminal keypress Did we get a control C ASCII char 3 from the 625 IF INSTR a CHR 3 THEN GOTO GotSG100 GOTO ConnectLoop GotSG100 Set a frequency and level on the 625 77 Send the following command string to the 625 A F1 18 4322 F2 0 0Z FO These characters have the following meaning A Reset the 625 to Sinewave mode Fl Move cursor to field 1 the frequency field 18 432Z2 Enter a frequency of 18 432 MHz F2 Move cursor to field 2 the level field 0 0Z Enter a level of 0 0 dBm FO Move cursor to field 0 turns cursor off PRINT 1 A F1 18 432Z F2 0 0Z FO After the 625 executes each command it will return a prompt character gt We wish to wait until after all prompts have come in Since that s when the 625 has finished executing the last command The GetResponsel subroutine has a time out feature which will accomplish this purpose GOSUB GetResponsel Wait for and get response from 625 to a Let the user know what s going on CLS PRINT CW mode selected Frequency and Level have been set PRINT PRINT PRINT Press any ke
3. 432X Enter a duration value of 432 mS F3 Move cursor to field 3 burst frequency field 5z Enter a freq value of 5 MHz 4 Move cursor to field 4 off time delay field 10y Enter a delay value of 10 seconds 0 Move cursor to field 0 turn cursor off O Goto offset entry 1 23Y Enter an offset value of 1 23 volts T Trigger the burst Example 3 A F1 LLLL UUU f0 This command sequence breaks down as follows A Reset 625 to Sinewave mode F1 Move cursor to field 1 frequency field LLLL Move the cursor left 4 times to the 1 000 Hz digit pos UUU Increment this digit 3 times fO Move cursor to field 0 turn cursor off 50 7 0 Arbitrary Waveform Mode 7 1 Quick Start Guide This guide will show you how to download and generate SINE FLT an example waveform in floating point format This file is on the supplied floppy disk in the arb examples directory 1 e Connect a serial port on you PC to the serial port connector on the rear of the 625 You may temporarily detach your serial mouse if needed to free up a serial port Mouse operation will be restored after the download If your computer has a 9 pin connector use a cable that is wired 1 1 or straight through If you computer has a 25 pin serial port connector install a 25 to 9 pin adapter available at most computer stores and then the 1 1 wired cable If you wish to build your own cable wire it as follows 9 pin 9 p
4. 70 mA can be drawn from the SIG Out output Sinewave Mode Parameters The Sinewave mode has the following front panel display Sinewave Mode 20 000 008 0 Hz 10 0 dBm ex T BA Jobs JCursor Field DTMF Ge SSB Function Puls DODO i UD gt DTMF Det Sw FSK S000 nino ur meas an FM on Power te Coen Clear O Arbitrary Sinewave Other Figure 5 1 1 Sinewave mode display Each parameter is described below 1 Frequency In this field enter the frequency of the sinusoid from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 2 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset By pressing this key you can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage on this jack 3V to 10V will turn off the output signal A logic low voltage on this jack OV to 10V will leave the output signal on For further information on the Ext Gating Input refer to s
5. A Reset the unit to Sinewave mode V Report hardware and software versions K1 0 Enable Disable front panel keys and knob E1 0 Enable Disable LCD echo to terminal F0 9 Move cursor to field 0 to 9 P Move cursor to Previous field orH Print help menu AE Returns C Each of these extra remote control commands is discussed below A Reset 625 to Sinewave mode This command resets the 625 to the Sinewave mode and turns the cursor off The output offset voltage is set to 0 0V When writing control software for the 625 it is a good idea to issue this command first so that the 625 is in a known state before further commands are issued Note The frequency and level values are not reset They are set to the values that existed the last time the unit was in Sinewave mode Or the power up default values if they hadn t been changed The RS232 baud rate remains unchanged 47 V Report hardware and software versions This command reports certain statistics particular to each 625 The hardware version and software version a hexadecimal serial number and a program memory checksum are all reported by this command BNC Corp model 625 Software Version 1 0 Hardware Version 1 0 S N F45E3412AC56 PM Checksum 0017829BB903 K1 0 Enable Disable front panel keys and rotary knob This command is used to disable or enable the front panel keypad and rotary knob To disable the front panel and knob issue the two ASCII c
6. 4 9 MHz dBm KHz Vp p Sec Hz mVp p mS keys These keys are used to select the units for a numeric value once it has been typed into a parameter field After entering all digits for a value you must press one of these keys to complete the entry of the value In other words these keys serve as an enter key since a value being edited in a cursor field is not accepted and processed until one of these keys is pressed After pressing one of these keys the 625 will make a double clicking noise to indicate that the value has been accepted If the entered value is outside the allowable range for the field the 625 will give an error beep and set the value to its upper or lower limit To enter a value in Volts or milliVolts use the Vp p and mVp p keys respectively When entering a value that has units not listed on the key i e percentage ohms etc any one of these three keys will work as an enter key 13 5 0 Mode Descriptions The following pages describe each operating mode of the 625 The meaning of each parameter that appears on the LCD display is described in detail 5 1 Basic Sinewave CW Mode Introduction The Basic Sinewave CW mode generates a sinewave of fixed frequency and level This mode is entered by pressing the Mode key and then the 0 key NOTE In this mode you can set the output frequency to 0 Hz and by specifying an offset voltage use the 625 as a variable voltage source with a 50 ohm output impedance Up to
7. PowerToggle Array 2 ChannelUp Array 3 ChannelDown Array 4 VolumeUp Array 5 VolumeDown Open serial port 1 for communication with the 625 with these parameters l Ignore the CD CTS DCD flow control lines Set a 5 sec maximum time out for basic to open the port Set the receive buffer to 2K bytes Disable the RTS flow control line Set the transmit buffer to 1K bytes File access type is Random Set random access buffer size to 2K N 2048 Gl Gl OPEN COM1 9600 n 8 1 CD0 CS0 DS0 0P5000 RB2048 RS TB1024 FOR RANDOM AS 1 LI Make sure a 625 is attached to the serial port 82 If we send the 625 a control E character it will respond with a control C We use this feature to s if a 625 is attached If a 625 cannot be found wait until one is attached User can abort the program at this point by pressing any key When power is applied to the 625 it prints a menu to the serial port We wish to disregard these characters so flush them GOSUB FlushBuffl Flush all received chars from buffer Tell the user to connect up a 625 PRINT Connect the 625 to the serial port and power the 625 ConnectLoop PRINT 1 CHR 5 Print a control E to 625 ASCII char 5 Wait for the 625 to give us some characters When they arrive put them into the string a GOSUB GetResponsel Wait for and get response from 625 to a Allow the user to exit the program by pressing a
8. and integer Binary format is also supported Waveforms may be generated in Continuous or Triggered modes In continuous mode the waveform is immediately restarted after the last point in the waveform is generated In Triggered mode the waveform halts after the last data point has been generated The system then awaits another Trigger condition before generating the waveform again 52 7 2 2 Feature Summary Arbitrary Waveform Generator True Arbitrary Waveform Generation Every point is generated regardless of clock rate Sample rate variable from 0 to 40 Megasamples Second in 1 Hz steps 32 768 maximum waveform points 12 bit vertical resolution Continuous Triggered operation Many data formats supported Floating Point Decimal Integer Hexadecimal Binary CSV and PRN formats Host computer independent No special protocols or software used for waveform downloads Function Generator Waveforms Positive Ramp Negative Ramp Triangle Positive Exponential Inverted Positive Exponential Negative Exponential Inverted Negative Exponential Random noise Sinewave Repetition Rate O Hz to 2 MHz in 1 Hz steps all functions Run mode Continuous or Internal External Triggered Output level 2 mV p p to 10 Vp p unloaded or 5 Vp p loaded Pulse Generator Frequency O Hz to 2 MHz in 1 Hz steps Duty Cycle Variable 0 to 100 in 1 steps Output Variable in amplitude and offset A TTL CMOS compatible output is simultaneously prov
9. offset voltages can be adjusted with a resolution of 1 mV Output levels can also be specified in dBm with 1 dBm resolution The unit is factory calibrated to produce accurate output levels and DC offset voltages The front panel shown in figure 1 1 1 has two output connectors The SIG Out connector is the main signal output The SYNC Out connector is a TTL CMOS compatible squarewave output It is a hardlimited version of the main output and is available in all modes The SYNC Out swings OV to 5V and is useful for driving digital circuitry The front panel of the Model 625 includes a full numeric keypad which makes it quick and easy to select a mode and enter or edit all parameters pertinent to that mode In addition a rotary knob allows quick adjustment of any numeric value and gives the user the ability to manually adjust a value across a wide range without having to retype The LCD display is a large 2 line by 40 column illuminated display It is large enough to display all operating parameters simultaneously and thus eliminate tedious submenus The user can select a modulating waveform that is either internally generated or externally supplied External signals in the DC to 35 KHz range are input to the 625 through the External Modulation In connector on the rear of the unit This input is high impedance about 30K ohms to avoid loading the source of the signal The unit also features an external digital input on the rear of the unit which
10. 2 Mark Frequency In this field enter the Mark frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 3 Space Frequency In this field enter the Space frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 4 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE For wideband FSK where the difference between Mark and Space frequencies is gt 1 0 MHz the output level may shift slightly between the mark and space frequencies The 625 has internal leveling circuitry which is disabled in this mode in order to offer higher FSK modulation rates NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 23 5 10 External FSK Mode Introduction The External FSK mode generates a frequency shift keyed signal of fixed amplitude An external digital input signal is used as a modulating signal to shift the output frequency betwe
11. 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE For wideband FSK where the difference between Mark and Space frequencies is gt 1 0 MHz the output level may shift slightly between the mark and space frequencies The 625 has internal leveling circuitry which is disabled in this mode in order to offer higher FSK modulation rates NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Trigger Input rear panel connector In Data Modulation mode this input functions as an external trigger input A logic low to high transition on this input will trigger the transmission This input has an internal pulldown resistor so that the input is held at a logic low when this input is left unconnected See section 2 0 for more information on the External Trigger Input 41 Downloading Modulation Message Data To download the modulation data you must send an ASCII message to the 625 through the serial port To do this first cable the PC s serial port to the 625 as shown in the Remote Operation section of this manual The following example has you generate an ASCII disk file and download it to the 625 If the file a
12. 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset By pressing this key you can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext FSK Input rear panel connector Apply the digital data to be modulated on this connector When this input is high the output phase is advanced 180 degrees When this input is low the output frequency is retarded 180 degrees Le this input switches the sign of the output carrier 37 5 24 Dualtone Generation Mode Introduction The Dualtone Generation mode generates an output signal which is the sum of two sinusoids of equal amplitude The frequency of each sinusoid may be individually specified with 1 Hz resolution In addition a phase offset may be specified which offsets the phase of one sinusoid with respect to the other The resulting dualtone waveform may be gated on and off for specified intervals This feature allows the user to pulsate the tone which can be especially useful when generating cadenced signals such as a busy tone ringback etc This mode is available under the other modes menu To enter the Dualtone Generation mode press Mode Clear 2 Dualtone G
13. 5V p p for example then 1 0 corresponds to 2 5V and 1 0 corresponds to 2 5V across a 50 ohm load For maximum signal fidelity you should design your waveform so that the peak values just fit into the range of 1 0 to 1 0 You will then be using the full output range of the DAC 2 To separate each number you may use commas tabs spaces carriage returns and or linefeeds semicolons colons or basically any character that is not among the following 0 1 2 3 4 5 6 7 8 9 e E X 3 You do not have to include an exponent i e e 5 If no exponent is given the 625 assumes that the exponent is 0 4 Whitespace characters are not allowed between the mantissa and the exponent 5 Use of the character for positive values is optional 6 To set the SYNC Out output high during a data point put a p or P BEFORE that data point The P character may have ben whitespace around it if desired SYNC Out is set low for all data points that do not have a p or P before them Example A six point waveform with SYNC Out set high on point 4 0 584737 3457e 4 p 0004857e 3 000485 1 0e 0 X The X character denotes the end of the data and is optional If the X character is missing the 625 will assume all data has been sent after 1 second timeout 60 7 8 2 Time amp Value Floating Point Format This format uses the same numerical format as Floating Point except that a Time or Point Number
14. Gen Wave Triangle Cont Rep Freq 2 000 000 0 MHz 1 000 mV Mhz dBm Store Recall Remote s Zo0 58Q Figure 7 5 1 Function Generator Mode display 1 Waveform In this field select the desired function generator waveform You may select from among the following 0 Positive Ramp 1 Negative Ramp 2 Triangle 3 Random noise 4 Positive Exponential 5 Inverted Positive Exponential 6 Negative Exponential 7 Inverted Neg Exponential 8 Sinewave Select the desired waveform directly using the number keys or use the arrow keys or wheel to scroll through the list 2 Continuous Triggered mode In this field select whether the waveform is generated continuously or on a single event basis If you select Continuous mode then the waveform is immediately restarted once the end of the waveform is reached If you select a Triggered mode then the waveform is halted after the last point is reached and the waveform is not restarted again until another trigger occurs The trigger can come from three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trig In connector 3 Sending an ASCII T to the RS232 port The 625 will simultaneously accept a trigger from all of the above sources To set Continuous mode press 1 To set Triggered mode press 0 Pressing any arrow key or rotating the wheel will toggle the run mode between Continuous and
15. MHz dBm KHz Vp p Sec Hz mVp p mS KeyS ooooccocccocnnocnoonononconoconaconccnncon nono nonnncnn cnn conc cnn non ncn neon neon nero conoce nn ncnnncnnnons 13 5 0 Mode Descriptions Sl Basic SmeWwive CWImMO iii A ae naan 14 5 2 Internal AM Mod oct 15 33 External AMimoden td A A ds 16 34 Anternal AA A 17 IEEE cad 18 5 6 ASA E A egg Sessa aeced EE I A a SERET 19 3 17 E PM O O a E ES 20 DS WS WEEP OE A 21 Payee AA AS AAA NN 23 Se LO External ESK DOE dl aaa 24 Dll BUS EMO Ade is at cath Ds Le a ce bro e o bs o 5d tal Dds 25 3 12 Tntemnmal SSB Modera dt ii ie 26 IAEA BM ri 27 5 16 DTMF Generation mode iii ia a da ideada 28 S217 D EME Detection mode nda alada 30 5 18 Power amp Voltage Measurement mode iii pist n 32 SAD Arbitrary modena csi rt aii di 33 SIN GA ce ed dee Caen N ete Recs vs abana Laat eee eh a hoa bain lad oh dav ok Dab na ae a gh aig Bae aaa Tage Hata Caen eee 34 Pat WE 7d 11 ea 610016 e pene ce eae E sl A a SET 35 3 22 Tntetiial B RS K MOG 6 aiveccclvsistecsccsesderoeodicead ss cseccutecsdesvedt decedhces esate e e eaa aee aa aE doestuact vadeddecdesiscsdeeests 36 3 23 External BPSK MOE siic5 ies 37 5 24 Dualtone Generation modesina E ceded datiedeseaveesutea Ueadecsesseed egeveduees seececceesedestteeeedeeveedenedteteesss 38 3225 Data Modulaci n Mode tl EOE ESE 40 5 26 Voltage Controlled Oscillator VCO Mode iea e E TN E S E E IE NEN 43 Table of Contents 6 0 Remote operation OL MintHODUCHION
16. Modulation In Connector rear panel Apply the signal to be measured to this connector For this mode the input signal may be in the 5 0V to 5 0V range Levels outside this range will be clipped by limiting circuitry Caution Levels outside 25V to 25V may damage the 625 5 RS232 Port You can have the power level value continuously sent to the terminal port by issuing the remote control command enable LCD echo See chapter 6 0 for further details on this command 32 5 19 Arbitrary Mode The Arbitrary Mode lets the user design custom waveforms on a PC and download them to the 625 for generation For complete details on the Arbitrary Mode refer to section 7 0 of this manual 33 5 20 Remote Mode This menu permits the user to specify the RS232 baud rate or to disable the port It might be useful to disable the port when you have a device connected to the RS232 port and you do not want characters that it may send to the 625 to affect the operation of the unit The Remote Mode displays the menu RS 232 baud rate 9600 Use 0 9 arrow keys or knob to select You may scroll through a list of the available baud rates by rotating the wheel or pressing an arrow key You may also specify a particular baud rate directly by pressing a number key according to the table below Disable the RS232 port 300 1200 2400 4800 9600 19200 38400 57600 115200 SAAAUNKRWN HE OS I To abort this question wi
17. SYNC Out set high on point 3 dota Ry ata ll S320 stl2 gt 20475 00382 The x character denotes the end of the data and is optional If the x character is missing the 625 will assume all data has been sent after 1 second timeout 63 7 8 5 Hexadecimal Format This format sends the same two s complement data that Binary format uses except that each nibble 4 bits of the hex value is represented by an ASCII character Each data point is a 16 bit value which is sent to the 625 as 4 ASCII characters Each ASCII character represents 4 bits as follows 0000 to 1001 Represented by an ASCII 0 to 9 1010 Represented by an ASCII a or A 1011 Represented by an ASCII b or B 1100 Represented by an ASCII c or C 1101 Represented by an ASCII d or D 1110 Represented by an ASCII e or E 1111 Represented by an ASCII f or F For example the 16 bit value 1101 0011 0101 1111 issentas d35f The 16 bit value is in two s complement format which represents a number from 1 0 to 1 0 as follows 8000 E000 FFFF 0 4000 7FFF 1 0 5 0 0 5 1 0 Although a 16 bit value is sent to the 625 the Arbitrary Waveform system uses a 12 bit D A converter so not all 16 bits are used Only the uppermost 12 bits are used to form the arbitrary waveform point The fourth lowest bit bit 3 is sent directly to the SYNC Out connector on the front of the 625 Example The data v
18. The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset By pressing this key you may enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext FSK Input rear panel connector Apply the digital data to be modulated to this connector When this input is high the output frequency is set to the Mark value When this input is low the output frequency is set to the Space value For more information on this input refer to chapter 2 0 24 5 11 Burst Mode The Burst mode generates a sinusoid burst of fixed frequency and level for a specified duration Both continuous and triggered bursts may be generated In the continuous burst mode the 625 continuously gates the output sinusoid on and off according to the values entered in the On and Off fields In triggered burst mode the output frequency is set to 0 Hz and the unit awaits a trigger condition When a trigger condition occurs the 625 delays for a time specified in the Off time field and then sets the output frequency to the specified value When the time specified in the On field has elapsed the 625 resets the output frequency to 0 Hz and awaits another trigger condition The trigger can come from three sources 1 Pressing the Trigger key 2 Applying a low to
19. Upper Sideband O 1 000 000 0 Hz 18 8 dBm Mh Next T t 7z 8 9 Jib curser EE iC DTMF Gen SSB Function Pulse KH Mod ao G o o Br one DTMF Det Sweep FSK Burst Store 0 Hz JR Ranta OM a G O Power Pwr meas AM FM M SINC SIG J tL L L clear O Arbitrar y X Sinewave Other TTL Cmos Zo 500 Figure 5 13 1 External SSB mode display 1 Upper Lower Sideband selection This parameter selects which sideband will be generated Single sideband modulation specifies that all energy in the modulated waveform should be either above the carrier frequency or below it Upper sideband places all signal energy above the carrier frequency and Lower sideband places all signal energy below the carrier frequency To select Lower sideband press 0 To select Upper sideband press 1 Pressing any arrow key or rotating the wheel will toggle the sideband selection between Upper and Lower 2 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps Note It is possible to enter values for the carrier frequency such that the upper sideband can exceed 20 0 MHz or the lower sideband can go below 0 Hz Care should be taken not to do this since distortion of the output waveform may result 3 Level In this field enter the output level from 2 mVp p to 3 5 Vp p in mV steps or from 50 0 dBm to 15 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm
20. Use of the character for positive values is optional 6 To set SYNC Out high during a data point put a p or P i BEFORE that data point The P character may have whitespace around it if desired SYNC Out is set low for all data points that do not have a p or P before them Examples of floating point numbers SYNC Out is set high on point 4 0 584737 3457e 4 p 0004857e 3 000485 1 0e 0 SendFloat IF PointNumber 1 THEN PRINT 1 WF Put header info before lst data point IF PointNumber 2 THEN PRINT 1 p Set SYNC Out bit for second point PRINT 1 PointVal Send Floating point number to 625 RETURN 69 i Send Integer data to 625 This format sends a base 10 number which is in the range 2047 to 2047 The integer numbers represent 1 0 to 1 0 as follows r 2047 1024 0 1024 2047 10 Sa 0 0 Fod 1 0 Rules for Integer format 1 The 625 expects all Integer values to be between 2047 and 2047 If a number falls outside that range the number is set to 2047 or 2047 These correspond to the peak values of the waveform If the output voltage r level were set for 5V p p for example then 2047 corresponds to 2 5V and 2047 corresponds to 2 5V across a 50 ohm load For maximum signal fidelity you should design your waveform so that the peak values just fit into the range of 2047 to 2047 You will then be using the
21. connect a serial cable between your computer and the RS232 port connector on the rear of the 625 For more information on how to do this refer to chapter 6 0 The program assumes you are using serial port 1 COM1 If you are using another serial port change the OPEN COM 1 statement in the beginning of this program It also assumes that the 625 baud rate is set to 9600 To check the 625 baud rate press the Mode then Offset keys This example program switches the 625 to DTMF Detection mode and displays the detected DTMF digits to the screen To detect DTMF digits the DTMF signal must be applied to the Ext Mod Input jack on the rear of the unit A schematic diagram which takes these tones from a telephone line is shown below 115K 1 12V 001 475K 4 200V 1 LM741 TE Telco Tip gt e J 6 a oot Connection Telco Ring 8 oy g NY E Mod In 475K onnector 1 001 d 200V 412V 115K 1 Figure A 1 Telephone line amplifier ik Caution Do NOT connect the Ext Mod In input directly to a telephone line High voltages exist on a telephone line which will cause permanent damage to the 625 This program does the following 1 Clear the screen 2 Open the serial communications port for communicating with the 625 Make sure there is a 625 connected to the serial port If we can t find one wait until it is connected up Command the 625 to generate 18 432 MHz at 0 0 dBm Wait for the user
22. display shows up to 40 detected digits When the 41st digit is detected this line of the display is cleared and the new digit is printed on the left hand side All detected digits are sent to the terminal port By connecting a computer to the terminal port the 625 can be used as a DTMF detection peripheral See the example program in Appendix A 2 RS232 Port All DTMF detections are printed to the terminal port When a DTMF digit is detected the digit 6 is given here as an example a carriage return and a linefeed plus the following text is sent to the terminal DTMF 6 31 5 18 Voltage amp Power Measurement Mode Introduction The Voltage amp Power Measurement mode measures the signal level on the Ext Mod In connector and displays the power and voltage level on the LCD display The Power Measurement mode applies to frequencies in the DC to 50 KHz range All signals outside this frequency range are attenuated by an internal lowpass filter A point by point true RMS power is calculated by the internal Digital Signal Processor DSP For the voltage measurement an averaging low pass filter algorithm is used To calculate power a system impedance must be specified If the input signal were to be applied across a load resistor then that resistor would dissipate power The power dissipated in the resistor is a function of the resistor s value The value of this load resistor is referred to here as the system impedance which must be
23. for and get response from 625 to a GOTO GetCommand Go get another remote control command SUBROUTINES 84 The subroutines needed for this example are listed in Appendix A Product Warranty The 625 is warranted against defects in material and workmanship for one year from the date of first purchase or shipment to the end user BNC will at its option repair or replace a defective unit under warranty Repairs are also warranted against defects in material and workmanship for one year The warranty does not cover damage caused by physical abuse electrical damage caused by connection to input sources and or output loads which exceed those specified for the product refer to the Users Manual for these limitations or damage resulting from repairs or alterations not made by BNC Product owner must authorize all repair charges before BNC can make repairs on units not covered by warranty This warranty specifically excludes any claims for merchantability or fitness of purpose and it does not cover consequential damages or loss of profit and in no case will BNC s liability exceed the original cost of the product This warranty is in lieu of all other warranties express or implied except for any specific legal rights imposed by law which may vary from state to state or province to province
24. high transition on the Ext Trig In connector 3 Sending an ASCII T to the RS232 port The 625 will simultaneously accept a trigger from all of the above sources Tip An external digital signal can be used to generate bursts by switching to Sinewave mode and using the Ext Gating In connector to gate the output waveform on or off The output is turned off when the input is at a logic high voltage 3V to 10V This input can be run up to 3 MHz Burst mode Trig Duration 10 000 mS 1 000 000 0 Hz Dly 5 000 mS 10 0 dBm 6 Mhz Next Trigger ft C7 68 L939 Jan JCursor DTMF Gen SSB Function Pulse 0 KHz ode O 000 O e o DTMF Det Sweep FSK Burst a 0 Hz Recall Remote 3 1 2 3 Davee a i SYNC Power Pwr meas AM FM on Out But e AO eae se G O Arbitrary X Sinewave 4 Other TTL Cmos Zo 50Q Figure 5 11 1 Burst mode display 1 Continuous Triggered Mode This field selects whether the bursts will be generated on a ongoing or single event basis To select Triggered mode press 0 To select Continuous mode press 1 Pressing any arrow key or rotating the wheel will toggle this value 2 Burst On Time Duration The burst will last for the duration specified in this field before being switched off You may enter a value from mS to 99 999 mS in 1 mS steps 3 Burst frequency The output frequency is held at this value during the burst You may enter from 0 Hz DC to 20 0000000 M
25. io dansa sada beats Ga ae bebe tend cea oh Ii di ica 44 6 2 HOOKUP sw sesisosetenay EEE EEEE EEE E ETE E davecuisontceencuy ENOO E 44 6 3 Checking your connection with HyperTerm cece eeceseceseccseecneeeeeeseecseeeseeeaeeseeesaecsaecsacsaecaecsaecsaecsaecseseeseseeeeseeaeeees 45 G4 Operations si sssesn Se eee ae Shed es ee Re ee ne a ed pt lo tke 46 6 5 Programming A ON 46 6 6 Command Mita is 47 GT Examples ui Noia ba 50 7 0 Arbitrary Waveform Mode 7 1 Arbitrary Waveform Quick Start Guide raras 51 7 2 Introduction to the Arbitrary Waveform Mode 7 2 1 Description of the Arbitrary Waveform Mode ooooococcnonnconoconocononononnnonancononanonnonnn crono ne cono cnnnrnn crono nn nrnn crac rin nnnncnnnos 52 ADD As A NN O 53 7 3 Switching to the Arbitrary Function Pulse Generator Mode 0 0 0 cccccccscesesessesseseesesseseeseaseees 54 7 4 Arbitrary Waveform Mode Display 0 0 0 ccccccssssssessesseesseessesseesneesnersessessessneeseesueeaneenesnessneeneeneeseesneenees 55 7 5 Function Generator Mode coccion 56 7 6 Pulse Generator Mode 0 od aneeconseqei tang aia souod in aps risa asad oMaepaE Nee 56 7 7 Downloading Arbitrary Waveforms 77 4 Using WAVELOADIEXE 3 csc0to0 sath aoa e ae rad 58 TAD Using Your OWN Pro Sram e ien d econo cen casepevevesdoensepsscovbenceveasepeagessceedpeenry sev enheesuvsebegauyedbdestevavepentontdascvenseyovees 59 7 8 Arbitrary Waveform Data Formats 7 8 1 Floating Point Format sssecsasces vg
26. key IF INKEYS lt gt THEN SYSTEM Exit on first terminal keypress Did we get a control C ASCII char 3 from the 625 IF INSTR a CHR 3 THEN GOTO GotSg100 GOTO ConnectLoop Gotsgl00 E Switch the 625 to Burst mod Send the following command string to the 625 A M6 F2 xxX Fl xxX F3 xxX FO These characters have the following meaning A Reset the 625 to Sinewave mode ensures the state of 625 M6 Go to Burst Mode F3 Move cursor to field 3 the burst frequency field XxX Enter a frequency of xx Hz infrared carrier freq F2 Move cursor to field 2 the burst duration field xxX Enter a duration of xx mS burst on time F4 Move cursor to field 3 the burst delay field XxXxX Enter a duration of xx mS burst off time FO Move cursor to field 0 turns cursor off PRINT 1 A M6 F3 PRINT 1 CarrierFreg X Send measured carrier freq PRINT 41 E2 PRINT 1 OnTime X Send burst on time PRINT 1 F4 PRINT 1 OffTimeS X Send burst off time PRINT 1 FO The 625 will now trigger a single burst for each t char we sent it After the 625 executes each t command it will return a prompt character gt We wish to wait until after all prompts have come in since that s when the 625 has finished processing the last t The GetResponsel subroutine has a time out feature which will accomplish this purpose GOSUB GetResponse
27. key Then use the gt and keys to position the cursor over the digit you wish to change Press the A or Y key to increment or decrement that digit Alternatively you can turn the rotary knob clockwise or counterclockwise to adjust the digit s value Attempting to set a parameter to a value outside the allowable range will cause the 625 to beep and set the parameter to its maximum or minimum permissible value Non numeric values toggle between preset values An example is Linear or Log type sweep You can toggle these values by pressing an arrow key or turning the wheel You can also press the O key to select the first value or the 1 key to select the second value 3 3 2 Entering a new value To enter a new value first move the cursor to the desired field using the Next Cursor Field key Then type in a new value using the numeric keypad If you make a mistake while typing in a value use the following three keys to correct mistakes 1 Use as a backspace key to erase the last digit you typed 2 Use Clear to erase all characters from the field value and start over 3 Use Next Cursor Field to abandon the editing process restore the old value and move the cursor to the next field Once all numbers are entered select which units apply to the newly entered digits To enter a frequency use the MHz KHz or Hz keys To enter a peak to peak voltage use the Vp p or mVp p keys To enter a dBm value use the dBm key To enter a
28. serves several purposes depending on the mode For most modes it serves as a gate to switch the RF output signal on and off In external FSK or BPSK mode it is a high speed data input for FSK or BPSK digital modulation of the output waveform at rates up to 3 MHz In modes that have a trigger function Burst Triggered Sweep etc this input serves as an external trigger which triggers a sweep or burst on the rising edge of the input The unit also features an EIA RS232 connector on the rear of the unit This permits the user to remotely control the 625 using ASCII characters No special hardware or protocols are needed any dumb terminal or computer serial port can be used An on line help menu which lists all remote control commands to the terminal is available The baud rate is adjustable up to 115 2 KBaud Software upgrades are also downloaded to internal Flash memory using this port An Arbitrary Waveform Generation Mode lets the user design custom waveforms on a PC and download them to the 625 for generation Up to 32 768 unique points may be specified and generated by a 12 bit DAC with a sampling adjustable from 0 Hz to 40 MHz in 1 Hz steps A logic waveform may also be generated simultaneously with the analog waveform The unit will accept many popular data formats for maximum flexibility Also included is a full featured Function Generator and Pulse Generator The function generator offers a set of pre stored waveforms which are generated using
29. signal Driving this input high triggers a sinewave burst or starts a sweep In the Continuous Sweep mode the sweep can be halted by driving this input high The sweep will resume when this input is brought low again In the Arbitrary Function and Pulse Generator modes this input serves as a trigger signal input If Triggered mode is selected the generation of your arbitrary function pulse waveform will commence on the rising edge of the trigger signal Caution Be careful to ensure that the input signal does not exceed the 10V limit Permanent damage to this input may result by exceeding this input voltage limit Rear Panel Ext Ext Trigger Ext Mod Satins Ref In Bas In RS232 1Vp p max 10 Mhz Zin gt 30KQ TTL CMOS Level 10 dB ROMO Interface Figure 2 0 5 Rear panel connectors 5 External Reference Input Arb Clock Arb Sync connectors The space for these connectors is reserved for the addition of future options 6 RS232 Interface connector This connector is used for remote operation of the 625 It is also used to download software upgrades to internal Flash memory To use the remote control feature attach the serial port on a computer or terminal to the RS232 Interface connector on the rear of the 625 On an IBM PC or compatible the serial port is on a male 9 pin or 25 pin connector The wiring is different for each type of connector For cabling diagrams See chapter 6
30. specified by the user As opposed to instruments which use a fixed value for this impedance i e 50 or 600 ohms the 625 allows any value from 1 to 999 ohms to be used for power calculations The Ext Mod In jack is high impedance about 30 K ohms If your system expects this signal to be terminated place a resistor of the appropriate terminating resistance across this input Power amp Voltage Measurement Mode Parameters Detected level on mod input 223 5 dBm Volts 1 652mV System impedance 600 ohm TTL Cmos Zo 50Q Figure 5 18 1 Power amp Voltage Measurement mode display 1 Power Level In this field the true RMS power level is displayed with 1 dBm resolution The calculated power level is calculated using the RMS input voltage and the specified system impedance 2 Voltage Level In this field the average DC voltage of the input signal is displayed If an AC signal is applied to the input this field will display the DC component of that signal 3 System Impedance In this field specify the value of the load resistance used to calculate power You may enter a value between 1 and 999 ohms To enter a value type 1 to 3 numeric digits If you type 3 digits the value is automatically entered If you only type 1 or 2 digits you can press the MHz key or the KHz key or the HZ key all are equivalent to enter the impedance value 4 External
31. the Arbitrary Waveform system The Pulse Generator allows the user to generate pulse waveforms with varying amplitude offset frequency and duty cycle 1 2 Feature Summary e Each unit is individually calibrated to ensure accurate output frequency level and offset voltage e Output level 2 mVp p to 10 0 Vp p unloaded Output level can be entered with 1 mV or 1 dBm resolution e Output offset 0 mV to 8 0 V unloaded Output offset can be entered with 1 mV resolution e TTL CMOS compatible logic output drives digital circuits directly e Flash Memory is used for code storage to enable easy software updates e 10 complete instrument setups can be individually stored or recalled Unit has a large easy to read illuminated LCD display which shows all operating parameters for each setup No confusing submenus e Full numeric keypad and rotary encoder make entering and adjusting parameter values easy e Standard RS232 port included Remote control operation requires no special hardware or software Baud rate is programmable All commands use ASCII characters Programming examples are included e External modulation input is wideband DC to 35 KHz High input impedance 30K ohm avoids loading the source signal External logic input allows user to gate output signal on off under logic control It can also be used as an external trigger signal External FSK and BPSK data is also brought in on this connector Modes e Basic Sine
32. the first 16 bits one word of the binary message The first bit to be transmitted is the MSB of this word AA20 This is the second 16 bits of the binary message Since the message is only 18 bits long only the MSB and the next lower bit will be sent in this case a 1 then a 0 After the last bit is sent the 625 turns off the carrier and awaits another trigger condition X This character denotes the end of the data and is optional If the X character is missing the 625 will assume all data has been sent after 1 second time out The 18 bit message for the data FE96 AA20 is sent as follows 1111 1110 1001 0110 10 t First bit transmitted E Last bit transmitted Since this message is only 18 bits long the last 14 bits of AA20 are ignored Note For more information on the Hexadecimal format please refer to the chapter on Hexadecimal Format in the Arbitrary Waveform section Triggering the Transmission The Data Modulation mode starts by setting the output frequency to 0 Hz and awaiting a trigger condition When a trigger condition occurs the unit will turn on the carrier and modulate the carrier until all bits have been sent out After the message has been transmitted the 625 will turn off the carrier and await another trigger event The 625 will simultaneously accept a trigger from these three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trig In connector 3 Sending an ASCII T to th
33. to obtain the desired function rep rate Repetition Rate Clock Frequency 16 000 5 Level In this field enter the loaded output level from 2 mVp p to 5 Vp p in 1 mV steps Into an open circuit the voltage swing will be twice the specified peak to peak value Waveforms with very narrow pulses may have signal energy above the cutoff of the output filter 10 MHz The resultant signal may have a distorted shape and reduced peak to peak output swing If the Pos Only field is set to Y then the output level is halved so that the output signal swings from OV to Y the specified level into a 50 ohm load or OV to the specified level into an open circuit Offset You can enter a DC offset voltage by pressing the Offset key For more information see section 4 4 57 7 7 Downloading Arbitrary Waveforms To download Arbitrary Waveform data to the 625 you must attach the serial port on your computer to the RS232 connector on the rear of the 625 For information on how to do this refer to the chapter Remote Control Hookup On the host computer you may use the supplied DOS program WAVELOAD EXE or you may send the data to the 625 from your own application program The next two sections give details on each The 625 does not need to be in Arbitrary Waveform mode to accept arbitrary waveform data The waveform will not be generated however until the 625 is switched to Arbitrary Waveform mode Downloading a waveform overwrites the previou
34. to press a key Switch the 625 to DTMF Detection mode Wait for the 625 to detect a DTMF digit and print it to the terminal A ANN 76 Program Start ECLARE SUB Delay X Declare functions used below l The Delay function waits x mS then returns ECLARE SUB Pause The Pause fctn waits for a keypress then returns CLS Clear the screen Open serial port 1 for communication with the 625 with these parameters Ignore the CD CTS DCD flow control lines Set a 5 sec maximum time out for basic to open the port Set the receive buffer to 2K bytes Disable the RTS flow control line Set the transmit buffer to 1K bytes File access type is Random Set random access buffer size to 2K N 2048 Gl OP Gl N COM1 9600 n 8 1 CD0 CS0 DS0 0P5000 RB2048 RS TB1024 FOR RANDOM AS 1 LI Make sure a 625 is attached to the serial port If we send the 625 a control E character it will respond with a control C We use this feature to s if a 625 is attached If a 625 cannot be found wait until one is attached User can abort the program at this point by pressing any key When power is applied to the 625 it prints a menu to the serial port We wish to disregard these characters so flush them GOSUB FlushBuffl Flush all received chars from buffer Tell the user to connect up a 625 PRINT Connect the 625 to the serial port and power the 625 ConnectLoop
35. uses this key to begin a sweep Triggered Burst and Data Modulation modes also use this key to begin the generation of a burst signals Arbitrary Waveform Function Generator and Pulse Generator modes use this key to begin the generation of a waveform in Triggered mode In modes that require a trigger the trigger can come from three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trigger In connector 3 Sending an ASCII T to the RS232 port The 625 will simultaneously accept a trigger from all of the above sources 4 6 Numeric keys 0 to 9 and The 0 to9 and keys are used to enter a numeric value These keys are used in the same manner as those on a calculator The key is only accepted when entering numeric values that can be negative i e dBm or offset values The keypress is ignored otherwise In DTMF Generation mode the key is used to generate the star DTMF digit and the key is used to generate the pound DTMF digit These keys are also used to select a mode after the Mode key is pressed once These keys are then used to select a mode indicated by the blue text written beneath these keys 12 47 M V gt keys The arrow keys are used to move the cursor and edit numeric values The 3 and keys move the cursor side to side within a cursor field They can be used to position the cursor over a digit within the field to modify Once the cursor is over the des
36. value in Volts use the Vp p or mVp p keys Ignore the p p designation To enter a time value use the Sec or mS keys Some units have dimensions not listed on these three keys AM mode has a value in percentage for example In this case any of the three units keys will work To type in a new percentage value for example type the percentage digits and then press the MHz dBm key or the KHz Vp p Sec key or the Hz mVp p mS key all are equivalent The 625 will indicate that a new value has been successfully entered by making a double clicking sound If a value is entered that is outside the allowable range the 625 will beep and set the parameter to its maximum or minimum permissible value An easy way to determine a maximum allowed value is to enter a very large value i e 999 MHz or Volts etc and observe the value that the 625 returns 10 4 0 The keys 4 1 Mode key The Mode key is used to change the operating mode of the 625 When pressed the LCD display is cleared and the question Mode is displayed The Mode key acts as a shift type key in that the meaning of each button on the front panel changes to that described by the blue wording beneath it To enter Sweep mode for example first press the Mode key and then press the number 4 key You can exit the Mode question by pressing the blue Mode key again The display returns to the previous mode unchanged Some modes are available on the 625 that are not printed on the front pan
37. will be saved before the mode is changed Switching back to Sinewave mode will restore the 5 MHz value in the frequency field If power is turned off however all parameters are reset to default values To save all parameters for a mode use the Store Recall command 6 6 Remote Control Commands The front panel keys and their associated ASCII chars are given by the diagram below Sending these characters to the 625 has the same effect as pressing the associated button on the front panel Tip To familiarize yourself with the remote operation of the 625 it is helpful to run a terminal program on your PC and manually type the commands and watch the response To get a help menu press H See section 6 3 for details Front Panel Programming FU Mhz dBm N Ms Field TMF Ge D KHz Vp p Sec TMF De gt R mV p p Trig M ode Offset Remote mS SYNC Out SIG Out wr mea el Arbitrary X Sinewave TTL Cmos Zo 509 Note Chars are case insensitive Figure 6 6 1 Front panel keys to ASCII command mapping Note Turning the rotary knob clockwise has the same effect as pressing the AM key multiple times Turning the rotary knob counter clockwise has the same effect as pressing the Y key multiple times In addition to the above ASCII command characters extra commands are available for remote control operation They are
38. 00CAL TXT Documentation file REMOTE APP1 BAS Source code for program in Appendix A APP2 BAS Source code for program in Appendix B UPDATE NOTE This directory contains a utility to update the operating software of the 625 SGLOAD EXE Utility which sends the update file to the 625 SGLOAD TXT Documentation file SG100 16 TLX Operating software data file 16 means software version 1 6 The name of this file changes with each new software release ARB WAVELOAD EXE Utility to download arbitrary waveform files to the 625 over the serial port WAVELOAD DOC Documentation file ARB BAS Example program to generate arbitrary waveforms in all supported data formats EXAMPLES Directory containing arbitrary waveform files in all supported formats 75 Appendix A Example remote control host program This chapter contains an example program written in Microsoft Quickbasic for remotely controlling the 625 It can be used as a starting point for writing your own remote control applications The program illustrates several basic techniques for remotely controlling the 625 with a control program The program begins by showing how to detect the presence of the 625 on the serial port It also shows how to set the operating mode and enter parameters such as frequency and level The program also parses information sent from the 625 to the host computer and displays that information on the screen Hardware Setup You must
39. 1 will render the following waveform on both the SIG Out and SYNC Out connectors JUN ULI l 62 7 8 4 Integer Format This format represents a full scale output with a base 10 number that ranges from 2047 to 2047 as follows 2047 1024 0 1024 2047 1 0 5 00 5 10 Rules for Integer format 1 The 625 expects all Integer values to be between 2047 and 2047 If a number falls outside that range the number is set to 2047 or 2047 These correspond to the peak values of the waveform If the output voltage level were set for 5V p p for example then 2047 corresponds to 2 5V and 2047 corresponds to 2 5V across a 50 ohm load For maximum signal fidelity you should design your waveform so that the peak values just fit into the range of 2047 to 2047 You will then be using the full output range of the DAC 2 To separate each number you may use commas tabs spaces carriage returns and or linefeeds semicolons colons or basically any character that is not among the following 0 1 2 3 4 5 6 7 8 9 e E X 3 Use of the character for positive values is optional 4 Leading 0 s are ignored 5 To set SYNC Out high during a data point put a p or P BEFORE that data point The P character may have whitespace around it if desired SYNC Out is set low for all data points that do not have a p or P before them Example A seven point waveform in integer format with
40. 27 as the last position on in the top right corner The cursor positions for the bottom line of the display begin with hex 40 for the lower left corner and end with hex 67 as the last position on in the bottom right corner If the cursor is currently off then the word off is printed instead of a hex value To enable LCD echoing send the two ASCII characters El To disable LCD echoing send EO Note Each time the El command is issued the display is re printed to the terminal You can use this command as a refresh function to observe the state of the LCD display at any time Tip To read the LCD display exactly one time you may issue the command sequence E1E0 This will send the contents of the LCD display exactly one time to the serial port and then disable further printing of the display contents 48 F0 9 Move cursor to field 0 to 9 This command is used to move the cursor directly to the specified field number Each parameter field on the LCD display has an associated number with it starting with 1 and increasing as you move from left to right then top to bottom For example the Sweep mode has seven fields Beg 1 000 000 0 Hz End 20 000 000 0 Hz Linear Trig Up Time 10 000 ms 10 0 dBm Each field is numbered as follows Field 1 Beg 1 000 000 0 Hz Field 2 End 20 000 000 0 Hz Field 3 Linear Field 4 Trig Field 5 Up Field 6 Time 10 000 mS Field 7 10 0 dBm Field 0 has special meaning turn the cursor o
41. 40 gt lt 00 gt lt fe gt lt d8 gt lt 45 gt lt 70 gt lt 80 gt lt 00 gt lt ff gt lt f 0 gt lt e6 gt lt d0 gt lt 00 gt lt 10 gt lt 00 gt lt f0 gt lt 0c gt lt 06 gt where lt xx gt represents the 8 bit binary value of the data byte sent to the 625 Note how whitespace is NOT allowed in Binary mode and the binary data begins immediately after the B character Note In binary format you cannot use an X character to denote the end of data Since the ASCII X byte could be interpreted as another binary value Note These data values are not represented by ASCII characters A binary disk file cannot be viewed using an ordinary text editor Garbled non printable characters will result You must use a hex editor to view such a file 65 7 9 Example Program ARB BAS ARB BAS is a program written in Microsoft Quick Basic which calculates the points of a sinewave and downloads them to the 625 as an arbitrary waveform The program can generate the waveform in all of the supported formats Floating Point Integer Hexadecimal and Binary and shows how SYNC Out can be asserted during waveform points This program can serve as a good starting point for writing you own waveform generation programs You can replace the sin x function with your own mathematical function and pick which data format you wish to use by calling the appropriate subroutine Binary format is the most efficient since it requires the least amount
42. B DC 20 MHz DC offset OV to 4 0 V 1 mV steps into 50 Q Output impedance 50 Q Freq accuracy 10 ppm 001 Spectral Purity gt 35 dBc DC 20 MHz External Modulation Input Max level in 5V 10V p p Input Impedance 30 KQ Bandwidth DC to 50 KHz RS232 port Asynchronous no parity 1 start bit 1 stop bit Baud rate Adjustable 300 bps to 115 2 Kbps Connector DB9 female type Operating Modes The carrier frequency for all modulation modes is 0 to 20 0000000 MHz 1 Hz steps Basic Sinewave CW Mode Output frequency 0 Hz to 20 000 MHz 1 Hz steps Frequency Modulation FM Mode Int modulation freq 0 Hz to 10 KHz 1 Hz steps Ext modulation freq DC to 35 KHz Peak frequency deviation 0 Hz to 5 0 MHz 1 Hz steps Phase Modulation PM Mode Int modulation freq 0 Hz to 10 KHz 1 Hz steps Ext modulation freq DC to 35 KHz Peak phase deviation 0 to 180 deg 1 deg steps Sweep Mode Start Stop freq 0 Hz to 20 000 MHz 1 Hz steps Linear or Log sweep Continuous or Triggered Up or Down Sweep time 1 mS to 60 Sec 1 mS steps Voltage Controlled Oscillator Mode VCO Endpoint freqs 0 Hz to 20 000 MHz 1 Hz steps Control input range 5 0V to 5 0V Control signal bandwidth DC to 35 KHz Burst Mode Continuous or Triggered via Front Panel RS232 or Ext TTL Duration 1 mS to 99 999 Sec 1 mS steps Delay 0 mS to 99 999 Sec 1 mS steps Dual Tone Multi Frequency DTMF Generate Mode Dialing digits genera
43. Berkeley Nucleonics Corp Model 625 Quick Start Guide 1 Apply power to the 625 After a display of the hardware and software versions and serial number the unit enters the Basic Sinewave mode of operation 2 The unit defaults to generating a 1 000000 MHz sine wave at a level of 10 0 dBm Changing Frequency To change the frequency press the Next Cursor Field button once The cursor will move to the frequency field The cursor position is indicated by a flashing digit You can change the frequency two different ways You can enter a new value or you can modify the current value To enter a new value type in the frequency using the numeric keypad Then press the MHz key for MHz or the KHz key for KHz or the Hz key for Hz The unit will make a double click sound to indicate that a new frequency value has been accepted To modify an existing value use the and keys to position the cursor over the digit you wish to change Then press the As or Y key to increment or decrement that digit Alternatively you can turn the rotary knob clockwise or counterclockwise to adjust the digit s value Changing Level To set a new output level press the Next Cursor Field button until the cursor flashes on the right hand side where the level is displayed You can change the level two ways You can type in a new value or adjust it with the wheel or arrow keys To enter a new level type in the new level value using the numeric keypad For a negati
44. Hz in 1 Hz steps 4 Burst Off Time Delay The burst waveform will be held at OV for the duration in this field before the sinewave is switched on In triggered burst mode this value may be viewed as a delay between the trigger event and when the output sinusoid is generated You may enter a value from 0 mS to 99 999 mS in 1 mS steps 5 Level In this field enter the 50 ohm loaded output level from 2 mVp p to 5 Vp p or from 50 0 dBm to 18 0 dBm Offset You can enter an offset voltage for the output waveform For more information on refer to section 4 4 Ext Gating Input rear panel connector In triggered burst mode this input functions as an external trigger input A logic low to high transition on this input will trigger the burst This input has an internal pulldown resistor so that the input is held at a logic low when this input is left unconnected See section 2 0 for more information 25 5 12 Internal SSB Mode Introduction The Internal SSB mode generates a Single SideBand SSB modulated signal of fixed carrier frequency An internally generated sinusoid is used as a modulating signal to modulate either the upper or lower sideband of a carrier sinusoid The modulation waveform is suppressed carrier i e no carrier energy is present in the modulated signal Internal SSB Mode Parameters The Internal SSB mode has the following front panel display O Int SSB 000 Hz Upper Sideba
45. LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 27 5 16 DTMF Generation Mode Introduction The DTMF Dual Tone Multi Frequency Generation mode generates the Touchtone dialing tones for the American telephone network The user can specify dialing digits 0 to 9 x as well as the extra DTMF digits A through D A start delay can be specified for each digit The duration of each digit can also be specified These two parameters make it possible to test the performance DTMF detection systems By sending a string of digits to dial to the RS232 port the 625 can be used as a speed dialer these digits are queued and dialed with the specified duration and delay between digits Note The 625 can generate a single DTMF digit on a repetitive basis by switching to Dualtone Generation mode and setting each dualtone frequency to that of the desired DTMF digit The ON and OFF times can then be set to repetitively generate the digit for the desired dur
46. Ref Ta FS In RS232 In 1Vp p max 10 Mhz Zin gt 30KQ TTL CMOS Level 18 dBm Interface 00 Figure 2 0 3 Connecting an external signal On this connector the user supplies a baseband signal below 50 KHz that is used to modulate an output carrier A microphone is shown here as an example It also serves as the input connector for DTMF signals in DTMF Detection mode and signals to be measured in the Voltage and Power Level Measurement mode This input is high impedance about 30K ohms It was made high impedance to avoid loading down the circuit supplying the signal This input is DC coupled within the 625 The signal on this input is internally lowpass filtered to a cutoff frequency of 50 KHz The input level for this connector is 5V max For external modulation modes a 1V p p signal will fully modulate the carrier If you apply a higher level signal than 1 Vp p the input signal will be distorted The distortion that will take place under these conditions is a hard limiting type i e the waveform will flat top at the positive and negative extremes Under these conditions the word Overld will be printed to the LCD for input levels that are too high ik Caution Levels outside the 25 V range on this input may damage the 625 4 External Trigger Gating FSK BPSK input The External Trigger Gating FSK In connector accepts an external digital signal on the rear of the unit as illustrated here Ext Tri
47. Remote Operation The baud rate is factory set to 9600 but may be changed via the front panel or RS232 port The other serial port parameters are 1 start bit 8 data bits 1 stop bit and no parity An ASCII hello screen is printed to the terminal on power up For further information refer to chapter 6 7 Power Supply In connector Plug in the 5 pin DIN connector from the supplied power supply here Power to the 625 is provided through this connection Warning NEVER use a power supply other than that supplied Other power supplies may have different voltage configurations and or pinouts which could permanently damage the 625 The power supply is specified for 100 240 VAC operation only If you have other input voltage requirements please contact the factory for a suitable supply 3 0 Operating the 625 3 1 Quick Start Guide 1 Apply power to the 625 After a display of the hardware and software versions and serial number the unit enters the Basic Sinewave mode of operation 2 The unit defaults to generating a 1 000000 MHz sinewave at a level of 10 0 dBm Changing Frequency To change the frequency press the Next Cursor Field button once The cursor will move to the frequency field The cursor position is indicated by a flashing digit You can change the frequency two different ways You can enter a new value or you can modify the current value To enter a new value type in the frequency using the numeric keypad Then
48. The level specified in External AM mode is the Peak Envelope Power or PEP As a peak to peak value this level represents the maximum peak to peak voltage swing that will result from a 100 percent modulated carrier If no modulating signal were applied the unmodulated carrier would have only half the peak to peak swing of a 100 modulated carrier NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 16 5 4 Internal FM Mode Introduction The Internal FM mode generates a frequency modulated signal of fixed amplitude An internally generated sinusoid is used as a modulating signal to vary the frequency of a carrier sinusoid Internal FM Mode Parameters The Internal FM mode has the following front panel display O Int FM 1 008 Hz Pk dev 19 008 Hz 1 088 000 8 Hz 19 0 dBm m Next Trigger t 7 8 C9 0 Dae Cursor 2 DTMF Ge SSB Function Puls KHz Aia DO i UD gt o
49. Triggered 3 Repetition Frequency In this field enter the frequency at which the function will be repeated You may enter from 0 Hz DC to 2 000000 MHz in 1 Hz steps If a value of O Hz is entered the function waveform clock is halted A high going synchronization pulse is given on the SYNC Out connector front panel at the start of the waveform In Triggered mode the waveform is generated once per trigger event The duration of each waveform will be 1 Repetition Frequency Tip Very low function frequencies lt lt 1 Hz can be generated by setting the Repetition Frequency to 1 Hz This fills the waveform memory with 16 000 points of the desired function Then goto Arbitrary Waveform Mode and enter the Clock Frequency to obtain the desired function rep rate Repetition Rate Clock Frequency 16 000 4 Level In this field enter the 50 ohm loaded output level from 2 mVp p to 5 Vp p in 1 mV steps Into an open circuit the voltage swing will be twice the specified peak to peak value Waveforms with very narrow peaks i e exponential may have signal energy above the cutoff of the output filter 10 MHz The resultant signal may have a distorted shape and reduced peak to peak output swing Offset You can enter a DC offset voltage for the output waveform by pressing the Offset key For more information on output offsets refer to the 625 Users Manual section 4 4 56 7 6 Pulse Generator Mode To enter the Pulse Generator mode pre
50. You may enter an ON time from 1 mS to 10 000 Sec in 1 mS steps 5 Output Off time In this field enter the amount of time for the output to remain off If you wish a continuous output set this value to O mS You may enter an OFF time from 0 mS to 10 000 Sec in 1 mS steps 38 6 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 15 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 Dualtone Examples The following table lists the parameters for some common dualtones used in the American Telephone Network Name Frequency 1 Frequency 2 On Time Ton Off Time Toff Dial Tone 350 Hz 440 Hz 1 mS 0 mS Ringback 440 Hz 480 Hz 2 000 mS 4 000 mS Busy 480 Hz 620 Hz 500 mS 500 mS Reorder 480 Hz 620 Hz 250 mS 250 mS DSN Preempt 440 Hz 620 Hz 1 mS 0 mS European 420 Hz 440 Hz various various Note The Phase Offset field value m
51. a change in the state of the line is detected the output phase is switched Since this input is sampled there may be a small but unpredictable delay between when the input changes and when the output phase is switched This delay is never greater than 1 1 430 000 sec 700 nS The net result is a 700 nS worst case jitter in the modulation edges The faster you modulate the output the more percentage of your modulating waveform this jitter becomes Although you can modulate beyond the stated maximum rate this jitter becomes increasingly greater percentage of your modulating waveform The jitter becomes 10 of the high or low time at 35 75 KHz This mode is available under the other modes menu To enter the External BPSK mode press Mode Clear 1 2 External BPSK Mode Parameters The External BPSK mode has the following front panel display Ext BPSK 1 000 000 0 Hz 210 0 dBm O E Next Trigger t C2 8 09 Ji o Jets DTMF Gen SSB Function Pul KH Mod 0 e o Oe W o DTMF Det Sweep FSK Burst Store Hz retain Senate gt C1 2 b3 Java Pur meas AM PM on fe Jeter O Arbitrary x Sinewave Other TTL Cmos Zo 50Q Figure 5 23 1 External BPSK mode display 1 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 2 Level In this field enter the output level either from
52. a resistor of the appropriate terminating resistance across this input i Caution Do NOT connect the Ext Mod In input directly to a telephone line High voltages exist on a telephone line which will cause permanent damage to the 625 See appendix A for a suitable telephone line interface Background Each DTMF dialing tone consists of two sinusoids of different frequencies which are added together to form the output waveform These frequencies were chosen so that they are not harmonically related The table below lists each dialing digit and its associated dualtone frequencies DTMF 0 941 Hz and 1336 Hz DTMF 1 697 Hz and 1209 Hz DTMF 2 697 Hz and 1336 Hz DTMF 3 697 Hz and 1477 Hz DTMF 4 770 Hz and 1209 Hz DTMF 5 770 Hz and 1336 Hz DTMF 6 770 Hz and 1477 Hz DTMF 7 852 Hz and 1209 Hz DTMF 8 852 Hz and 1336 Hz DTMF 9 852 Hz and 1477 Hz DTMF 941 Hz and 1209 Hz DTMF 941 Hz and 1477 Hz DTMF A 697 Hz and 1633 Hz DTMF B 770 Hz and 1633 Hz DTMF C 852 Hz and 1633 Hz DTMF D 941 Hz and 1633 Hz 30 DTMF Detection Mode Parameters The DTMF Detection mode has the following front panel display DTMF detection on Ext Mod input Store Recall Remote SYNC SIG Out Out Clear er TTL Cmos Zo 500 Figure 5 17 1 DTMF Detection mode display 1 DTMF Detected Digits All detected digits appear on this line of the display The
53. al port These commands let you perform such tasks as disabling the keypad printing a help screen resetting the 625 etc Section 6 5 describes each command When a key is pressed on the front panel of the 625 its associated ASCII character is echoed out to the serial port This enables a control program to monitor and act upon front panel keypresses 6 2 Remote Control Hookup To use the remote control feature you must attach the serial port on your computer or terminal to the RS232 connector on the rear of the 625 On an IBM PC or compatible the serial port is a male 9 pin or 25 pin connector The wiring is different for each type of connector For the 9 pin type connector on the back of an IBM PC or compatible the serial port cable is wired 1 1 straight through Although all pins can be wired only pins 2 3 and 5 need be connected See the figure below 1 6 To To 3 SG 100 s PC 5 Figure 6 2 1 RS232 hookup to a PC s 9 pin connector The easiest way to cable to a 25 pin type connector on the back of a PC is to install a 25 pin to 9 pin adapter and use a 1 1 wired cable These adapters are available at most computer supply stores Otherwise you must use a cable that reverses pins 2 and 3 and wires pin 5 to pin 7 See diagram below i o To PC NIN SG 100 aro a Figure 6 2 2 RS232 hookup to a PC s 25 pin connector To test the
54. alue E468 is handled as follows E 4 6 8 Ea Dg 110 e bo These 12 bits are sent to the DAC 5 ak This bit is sent to the SYNC Out Connector Rules for Hexadecimal format 1 Each Hexadecimal value may have 1 to 4 characters Negative values require 4 characters since the most significant bit of the value bit 15 must be a 1 for negative values If there are fewer than 4 characters the value is interpreted as positive Characters are not case sensitive 2 To separate each number you may use commas tabs spaces carriage returns and or linefeeds semicolons colons or basically any character that is not among the following 0 12345678 9aAbDBcCdADeEEFX 3 The most significant nibble character is the first that is sent to the 625 For example to send the value 1234 the 1 is sent first then the 2 etc 4 The SYNC Out output is controlled by bit 3 in the low byte If this bit is set to 1 SYNC Out is set high If this bit is set to 0 SYNC Out is set low Example A 10 point waveform in hexadecimal format with SYNC Out set high on point 3 0 4000 fed8 4570 8000 f ff0 E6DO0 10 FO C06 x The x character denotes the end of the data and is optional If the x character is missing the 625 will assume all data has been sent after 1 second timeout 64 7 8 6 Binary Format This is the fastest way to send points to the 625 since it transfers the data point with only 2 characters It is also the least forgivin
55. anel You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps NOTE You are not allowed to enter a end frequency that is less than the start frequency 3 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 External Modulation In rear panel connector Apply the control voltage to this connector For this mode the input signal may be in the 5 0V to 5 0V range Levels outside this range will be clipped by limiting circuitry Caution Levels outside 25V to 25V may damage the 625 43 6 0 Remote Operation 6 1 Introduction The Remote Operation feature allows the user to control all operations of the 625 with a terminal or computer Commands and responses use ASCII characters permitting a dumb terminal to be used to control the 625 Each key on the front panel keypad has an ASCII letter associated with it Sending this letter to the 625 through the serial port has the same effect as pressing that key on the keypad In addition there are extra commands that are only available from the termin
56. ating and carrier frequencies such that the upper sideband can exceed 20 0 MHz or the lower sideband can go below 0 Hz Care should be taken not to do this since distortion of the output waveform may result 4 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 26 5 13 External SSB Mode Introduction The External SSB mode generates a Single SideBand SSB modulated signal of fixed carrier frequency An externally supplied signal on the Ext Mod In connector is used to modulate either the upper or lower sideband of a carrier sinusoid The modulation waveform is suppressed carrier i e little carrier energy is present in the modulated signal External SSB Mode Parameters The External SSB mode has the following front panel display Ext SSB
57. ation and repetition rate Refer to the chapter on Dualtone Generation mode for more information Background A DTMF dialing tone consists of two sinusoids of different frequencies which are added together to form the output waveform These frequencies were chosen so that they are not harmonically related The table below lists each dialing digit and its associated dualtone frequencies DTMF 0 941 Hz and 1336 Hz DTMF 1 697 Hz and 1209 Hz DTMF 2 697 Hz and 1336 Hz DTMF 3 697 Hz and 1477 Hz DTMF 4 770 Hz and 1209 Hz DTMF 5 770 Hz and 1336 Hz DTMF 6 770 Hz and 1477 Hz DTMF 7 852 Hz and 1209 Hz DTMF 8 852 Hz and 1336 Hz DTMF 9 852 Hz and 1477 Hz DTMF 941 Hz and 1209 Hz DTMF 941 Hz and 1477 Hz DTMF A 697 Hz and 1633 Hz DTMF B 770 Hz and 1633 Hz DTMF C 852 Hz and 1633 Hz DTMF D 941 Hz and 1633 Hz 28 DTMF Generation Mode Parameters The DTMF Generation mode has the following front panel display DIMF generation Duration 200 mS Delay 1 000 mS Level 10 0 dBm E Next Trigger 4 C7 8 9 C Jil Corser DTMF Gen SSB Function Pulse 0 KHz lade OOOO ON one DTMF Det Sweep FSK Burst ies 0 Hz Recall R SO 06 Orie bee SYNC SIG Out Out Pwr meas AM FM M lt L J LO L J jese O Arbitrary Sinewave Other TTL Cmos Zo 50Q Figure 5 16 1 DTMF Generation mode display 1 Generated DTMF Digit The last DTMF digit that was generated is
58. ay be set to any value to properly generate these tones 39 5 25 Data Modulation Mode Introduction The data modulation mode will digitally modulate a binary message of up to 960 bits 60 words in length The data is digitally modulated using FSK modulation at an adjustable baud rate The mark and space frequencies may be independently specified from 0 Hz to 20 MHz with 1 Hz resolution The baud rate is adjustable from 0 Hz to 130 KHz in Hz steps By specifying a Mark or Space frequency of 0 Hz 100 digital AM modulation may also be done The Data Modulation mode operates in a triggered burst mode The Data Modulation mode starts by setting the output frequency to 0 Hz and awaiting a trigger condition When a trigger condition occurs the 625 examines the first data bit of the binary message and sets the output frequency to the Mark frequency if the bit is a 1 or to the Space frequency if the bit is a 0 The output is held at that frequency for a period of time specified by the Baud rate field After that the next bit of the modulation message is processed and so on until all bits have been modulated After the last bit has been modulated the 625 resets the output frequency to 0 Hz and awaits another trigger condition Using the Data Modulation Mode To use the Data Modulation mode you must do the following 1 Switch the 625 to Internal FSK mode by pressing Mode 5 1 2 Enter the Baud rate Mark amp Space frequencies and output lev
59. ceisc cios aia stave sve capes EOL atari pain 60 7 8 2 Time amp Value Floating Point Format CSV PRN sceescecssscesececeseceeceecaeceeeeecsaeceaeecsaeceneecaeeseaeecueeeneesas 61 7 8 3 Digital Forti A Subs da iodo ciao 62 ESA Inte per MO e et dias ne Oh 63 7 83 Hexadecimal Ford Id laa 64 7 8 0 Binary Porta ie 65 7 9 Example Program ARB BAS A Quick Basic program to generate and download arbitrary waveforms in a variety of data formats 66 8 0 DC Operation Option SN cesses tecess ce sscasces scpesscobspnsnes decaat go enescoes espace RESES R E E SeS OS EESE sovesucedsca sues syeeabeosaeescenaseessoode 73 PO SGC CHNC ALOIS 58S cin a A 74 10 0 The Floppy Diskette 10 1 Contents of the accompanying diskette oooonnncnnnnnnnnnonnnonnnoncnononncnnoconocn nono nonnnonn nono nnnnnnnn non none cone cn neon nc nono nano nn nr nn rnnannnons 75 Appendix A RS232 remote control example host program cesses toinne eva oera Ee e o eE EE O E e oe 75 An example program written in Basic to remotely control the 625 It also illustrates how to parse detected DTMF digits sent from the 625 to the host computer Appendix B Application example Television remote control oooocononnnccnnccnoonconoconoconocononnnonononnnonn cnn onnn nan nc ne cone cn nero neon corno 81 An example program to remotely control the 625 in Burst mode The 625 drives an infrared LED to emulate a television remote control transmitter RY RAY erased a rae ee ee Insid
60. come from a front panel keypress a rising edge on the EXT Trigger connector or an ASCII T on the terminal port Once a trigger occurs the output frequency is swept to the stop frequency and the sweep is then reset to the start frequency The unit then awaits another trigger condition For downward sweeps the output frequency begins at the stop frequency and ends at the start frequency Sweep Mode Parameters The Sweep mode has the following front panel display Beg 1 000 000 0 Hz End 20 008 008 80 Hz LinearlContlUp lTime 60 080 mS 10 0 dBm O Mhz Next Trigger dBn Cursor ie d Offset Store Recall Remote SYNC SIG ut Out 0 Clear C TTL Cmos Zo 50Q Figure 5 8 1 Sweep mode display 1 Start Frequency In this field enter the starting frequency for the sweep You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps NOTE You are not allowed to enter a start frequency that is greater than the stop frequency 2 Stop Frequency In this field enter the ending frequency for the sweep You may enter from 0 Hz to 20 0000000 MHz in 1 Hz steps NOTE You are not allowed to enter a stop frequency that is less than the start frequency 3 Linear Log sweep In this field select how the sweep frequency is incremented during the sweep A linear sweep means that the frequency is incremented by a constant amount for a give
61. connection run a terminal program and set the serial port parameters to 9600 baud 1 start bit 8 data bits 1 stop bit and no parity When the 625 is powered up a text message is printed to the terminal If you don t see it check your cabling See the following section for instructions on checking your connection on a PC using HyperTerm Also press Mode then Offset and verify that the 625 baud rate is set to 9600 44 6 3 Checking your connection with HyperTerm A terminal program included with Windows 95 called HyperTerm can be used to test the serial port connection between your computer and the 625 This will verify that your cabling is good After installing the cable run HyperTerm from the Windows 95 start menu as follows e Launch the program by clicking on START Programs Accessories HyperTerminal e Double click on Hypertrm exe e The program will ask you for a connection name Type in a name for the connection and hit OK e You will then be presented with a Phone Number menu Where it says Connect Using select Direct to COMx where x 1 2 3 4 depending on which serial port you are using and hit OK e You will then be presented with a Port Settings menu Set the parameters as follows Bits per second 9600 Data bits 8 Parity None Stop Bits 1 Flow Control None then hit OK You now have a terminal connection established with the 625 Hit the key You should see a command menu in response If you do n
62. cross a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 17 5 5 External FM Mode Introduction The External FM mode generates a frequency modulated signal of fixed amplitude An externally supplied signal on the Ext Mod In connector is used to vary the frequency of a carrier sinusoid External FM Mode Parameters The External FM mode has the following front panel display External FM Pk dev 10 000 Hz 1 000 000 Hz 10 8 dBm Mhz N aa t 7 8 C9 C ie Er ES DTMF Gen SSB Function Pulse KH Mod CH 4 8 8 Oe Br DTMF Det Sweep FSK Burst Store 0 Hz ean tics rene gt 11 2 2 Jaber m SYNC SIG Out 0 Pur meas an FM on Power tE J LOI Le L Jess O Arbitrar y x Sinewave Other TTL Cmos Zo 500 Figure 5 4 1 External FM mode display 1 Peak Frequency Deviation In this field specify the degree to which the modulating signal is allowed to change the carrier frequency You may enter from 0 Hz no change to 5 0 MHz in 1 Hz
63. d Other Clear key to bring up a scroll menu which displays the additional modes You can scroll through the list with the arrow keys or the wheel To select one of these modes enter its menu number Some modes may not yet be offered or may be offered as an option Contact the factory for the availability of these modes 3 3 Changing Values For each operating mode the LCD display shows a number of fields that hold operating parameters for the selected mode i e sweep start frequency stop frequency etc To change the value of a parameter you must first move the cursor to the desired field on the display To do this press the Next Cursor Field key Each time this key is pressed the cursor is advanced to the next field on the display When the cursor is advanced to a new field it is placed in the rightmost position within that field and is indicated by a flashing character One of the valid cursor fields is off When the cursor is off numeric values cannot be altered until the cursor is switched back on This feature is designed as a lockout function to safeguard parameter values from being changed by inadvertent keypresses or turns of the rotary knob Once the cursor has been moved to the desired field the field value can be changed in two ways You can modify a current value or you can enter a new value 3 3 1 Modifying a value To modify an existing value first move the cursor to the desired field using the Next Cursor Field
64. displayed in this field To generate a DTMF digit the cursor must be either in this field or the OFF position If the cursor is in any other field i e Delay or Duration fields then the keypad functions to enter those parameters Several keys on the front panel are used to generate DTMF digits other than 0 to 9 They are listed here To generate the DTMF digit press the minus key To generate the DTMF digit press the period key To generate the A DTMF digit press the A key To generate the B DTMF digit press the W key To generate the C DTMF digit press the Y key To generate the D DTMF digit press the key 2 DTMF Duration The DTMF tone will remain on for the time specified in this field You may enter a value from 1 mS to 10 000 mS 10 seconds in 1 mS steps 3 DTMF Delay The 625 will delay generation of the DTMF tone by the time specified in this field This parameter is used primarily to add an inter digit delay between dialed digits so that the user can send a string of ASCII digits to the RS232 port for speed dialing The 625 will insert the specified delay between the dialed digits You may enter a value from 0 mS to 10 000 mS 10 seconds in 1 mS steps 4 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 15 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which wi
65. e 3 Carrier Frequency In this field enter the frequency of the carrier from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 4 PEP Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified in Internal AM mode is the Peak Envelope Power or PEP As a peak to peak value this level represents the maximum peak to peak voltage swing that will result from a 100 percent modulated carrier If no modulating signal were applied the unmodulated carrier would have only half the peak to peak swing of a 100 modulated carrier NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high level turns off the output For further information on the Ext Gating Input refer to section 2 0 15 5 3 External AM Mode Introduction The External AM mode generates an amplitude modulated signal of fixed carrier frequency An externally supplied signal on the Ext Mod In connector is used as a modulating signal to vary the amplitude of a carrier si
66. e Back Cover 1 0 Introduction Figure 1 0 1 The BNC model 625 This manual contains operating instructions for the BNC Model 625 Signal Generation and Processing Engine Complete specifications for the Model 625 are given in Chapter 9 1 1 Description DTMF Gen ulse yb Pe 6 1 DTMF Det Sweep FSK Burst Cacti E R 11 gt 1 2 3 l y pile ig F AM FM on ED C Ce E O Jeer Arbitrary X s TTL Cmos Zo 50Q Figure 1 1 1 625 front panel The Model 625 is a versatile signal source capable of generating a variety of waveforms including CW and wideband sweeps from D C to 20 MHz in steps of 0 1 Hz The signals are generated using direct digital waveform synthesis DDS techniques for high accuracy and precision A wide variety of modulation types are available including AM FM PM and FSK A high speed Digital Signal Processor DSP controls every aspect of the DDS system and is used internally for the precise generation and processing of all modulating waveforms The use of DSP technology makes possible additional modes which process or analyze an externally applied signal such as DTMF detection and power level measurement The 625 is capable of supplying an output level of 10 0 Vp p with an offset voltage of 8 0V unloaded The output impedance is 50 ohms therefore the 50 ohm loaded output level is 5 0 Vp p with an offset voltage capability of 4 0V The output level and
67. e RS232 port Saving the Message You may save the downloaded message by saving the instrument setup using the STORE RECALL button Up to 10 instrument setups including 10 messages may be stored Modulation data messages are only saved when the unit setup is stored in Internal FSK mode 42 5 26 Voltage Controlled Oscillator VCO Mode Introduction The Voltage Controlled Oscillator mode allows the user to vary the output frequency between two specified frequencies using an externally applied voltage By applying a voltage between 5 0V and 5 0V to the External Modulation In connector rear panel the output frequency can be adjusted between the Start and End frequency values The control input bandwidth is DC to 35 KHz To enter this mode press Mode 4 2 VCO Mode Parameters The Voltage Controlled Oscillator mode has the following front panel display VCO Start End 20 000 000 0 Hz Arbitrary X Sinewave TTL Cmos Zo 58Q Figure 5 26 1 VCO mode display 1 Start Frequency This is the output frequency when 5 0V is applied to the External Modulation In connector rear panel You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps NOTE You are not allowed to enter a start frequency that is greater than the end frequency 2 End Frequency This is the output frequency when 5 0V is applied to the External Modulation In connector rear p
68. e and negative voltages can be entered To exit the offset entry screen and return to the current mode press the Offset key again The offset voltage value can be entered in the same manner as any other numeric value You can also use the wheel to modify a particular digit in the value Any voltage within the range of 4 0 to 4 0 can be entered NOTE The offset voltage specified is a 50 ohm LOADED value This is the voltage that will appear across a 50 ohm load connected to the SIG Out connector If you are connecting the output to a high impedance load the output voltage will be twice that entered NOTE Care must be taken when specifying an output offset voltage and level such that the output does not clip The loaded output cannot swing higher than 4 0V or lower than 4 0V Therefore Offset voltage 1 2 Vp p lt 4 0 The 625 can be used as a variable voltage source by setting the output frequency to 0 0 Hz while in Sinewave mode Then set the offset voltage to the desired output voltage Remember the output impedance is 50 ohms Up to 70 mA can be drawn from the output under these conditions This key is also used to select the RS232 baud rate after the Mode key is pressed once By pressing Mode then Offset a menu of baud rates for the 625 is presented For more information refer to the chapter on Remote Mode 4 5 Trigger key The Trigger key is used in modes that require a trigger event to begin a process Triggered Sweep mode
69. e of 0 Hz to 130 000 Hz 2 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 3 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset By pressing this key you can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to turn the output signal on or off A logic high voltage on this jack 3V to 10V will turn off the output signal A logic low voltage on this jack OV to 10V will leave the output signal on For further information on the Ext Gating Input refer to section 2 0 36 5 23 External BPSK Mode Introduction The External BPSK mode generates a phase shift keyed signal of fixed amplitude The logic level on the Ext FSK In connector is used as a modulating signal to shift the output phase between 0 and 180 degrees The modulation is suppressed carrier i e no carrier energy is present in the output waveform NOTE External BPSK is implemented by sampling the Ext FSK In line at 1 43 MHz When
70. e returned for each command as it is executed All commands require less than 300 mS to execute except for the store or recall commands which require several seconds to complete 3 All whitespace carriage returns linefeeds tabs spaces and commas between commands is ignored Invalid commands ASCII characters that are not listed in the command menu are likewise ignored 4 A command does not have to finish execution before another can be sent All characters received by the 625 are buffered up and executed in the order they were received The programmer should allow sufficient time for the 625 to execute each commands and for the signal output to settle into the desired state 5 If the 625 is reporting data to the control program it will place a colon character before the data This makes it easy for the control program to parse a returned string and extract the character s needed Some examples of returned values are Example 1 DTMF Detection Mode detected digits DTMF Example 2 Hardware Software version serial number the V command BNC Corp model 625 Software Version 1 0 Hardware Version 1 0 S N F45E3412AC56 PM Checksum 0017829BB903 6 When the operating mode of the 625 is changed all parameter values for the previous mode are retained in memory as long as power is applied to the unit For example if Sinewave mode with an output frequency of 5 MHz is changed to Sweep mode the Sinewave mode 5 MHz value
71. e wheel will toggle the sweep between Up and Down 6 Sweep time In this field you specify how long it takes the sweep to increase the frequency from the start frequency to the stop frequency You may enter 1 mS to 60 000 mS 60 seconds in 1 mS steps In Continuous sweep mode the sweep may be halted by applying a logic high to the Ext Gating Input connector on the rear of the unit Doing so also halts the sweep timer i e the sweep time will be lengthened by the amount of time that the sweep is halted 7 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 SYNC Out Connector front panel This TTL CMOS compatible output supplies a high going pulse at the start of each sweep Useful for triggering scopes or other equipment at the start of each sweep Ext Gating In Connector rear panel connector This TTL compatible input is used in two different ways depending on whether the sweep mode is Continuous or Triggered In Continuous sweep the user can halt the sweep dead in its tracks by applying a log
72. ected EndPortSel Command the 625 to enter Arbitrary Waveform Generation Mode Note The 625 does not need to be in Arbitrary Waveform generation mode to accept data points over the serial port We switch to Arbitrary waveform mode here as an example of remotely controlling the operation of the unit and to have the waveform generated after the download y For more information on Remote Control See the 625 Users Manual Put the 625 in Arbitrary Waveform mode set parameters PRINT 1 ML1 F11 F240Z F35Y ML1 Set Arbitrary Mode F11 Set Continuous not Triggered mode F240Z Set sampling clock to 40 MHz F35Y Set output level to 5V p p Main Loop 67 would like the data in This loop calculates each point of the arbitrary waveform It then calls one of several subroutines depending on what format you to send the data to the 625 Total number of points generated accumulator to 0 NUMPOINTS 80 1 Phase 0 Reset sinewav PhaseInc 2 3 1415926 NUMPOINTS FOR PointNumber 1 TO NUMPOINTS phas Phase goes 0 to 2 Pi This loop generates the points and sends them to the 625 Basic returns You may insert but be sure that the returned value ranges PointVal xpect 3 67e 2 586 fed7 124 63c8 2047 185 2047 le lt hi byte gt lt low byte gt OLE pra Advance the phase of our sinusoid Note Here we call a fu
73. ection 2 0 14 5 2 Internal AM Mode Introduction The Internal AM mode generates an amplitude modulated signal of fixed carrier frequency An internally generated sinusoid is used as a modulating signal to vary the amplitude of a carrier sinusoid The modulation waveform is not suppressed carrier i e a fixed amount of carrier power is always present in the modulated signal Internal AM Mode Parameters The Internal AM mode has the following front panel display O Int AM 1 088 Hz Percent Mod 100 O 1 000 000 Hz PEP level 18 8 dBm 5 Next T t 7 C8 09 Ji Jrs DTMF Gen SSB Function Pulse KHz ode 4 5 6 i EB ove DTMF Det Sweep FSK Burst Orea 0 Hz Recall Remote gt 1 2 23 C Jae i m SYNC Bowen Pwr meas AM FM M Out Out i JLart aus Os Figure 5 2 1 Internal AM mode display 1 Modulating Frequency In this field enter the frequency of the modulating sinusoid from 0 Hz to 10 000 Hz in 1 Hz steps 2 Percentage modulation In this field enter the degree to which the modulating signal is allowed to change the carrier amplitude You may enter from 0 no change to 100 maximum change in 1 steps To enter a value type 1 to 3 numeric digits If you type 3 digits the value is automatically entered If you only type 1 or 2 digits you can press the MHz key or the KHz key or the Hz key all are equivalent to enter the percentage valu
74. ed by BNC is believed to be accurate and reliable However no responsibility is assumed by BNC for its use nor for any infringement of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under the patent rights of BNC Corp PRINTED IN U S A Printing History First Edition 1 96 Second Edition 6 96 Third Edition 6 97 Fourth Edition 10 97 Fifth Edition 4 98 Berkeley Nucleonics Corp Tel 415 453 9955 Internet _http www berkeleynucleonics com 2955 Kerner Blvd Suite D Fax 415 453 9956 San Rafael CA 94901 Table of Contents 1 0 Introduction to the 625 ET Description of the G25 tt it lie 2 1 2 Feature S O 3 2 0 Hooking up the 625 A discussion of the input and output connectors 0 0 cee eeseceseceececesseeenceceseeesaeecescessneecueecescecseeeeeneeceeeeeaeecsueeeseaeceeeeeneecnees 4 3 0 Operating the 625 IL QUE Start Gide artes eile a oia 8 3 2 Selecting an operatin S Mode uta ia 9 3 3 Changing Valles parceiro eirian s r aae r ETE EEE Eare ET EAEE EER EE E rE ET ETE set sens a E E EESE 10 3321 Moditying n existing Valie iii 10 3 3 2 EMering anew Value cti a Ai 10 4 0 The keys AL Mode key A AA ia 11 4 2 Next Cursor Piel diss cco vies dit 11 AB Store Recall Ke Yoco tiara tas 11 AA Olsen no o 12 SS A NO 12 4 6 Numeric keys C0 to 9 and i aenn EEE T EEEE EN REEN ETE E REE 12 BO ER Re CYS E E E E E E 13 4 81 Clear key atan eii 13 4 9
75. either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 20 5 8 Sweep Mode Introduction The Sweep mode continuously changes the frequency of a fixed amplitude sinusoid between a specified start frequency and a specified stop frequency The user can specify how long it takes for the sweep to reach the stop frequency The frequency may be stepped between the start and stop frequency linearly i e the frequency is incremented over time by a constant value or a logrithmically where the frequency is advanced logrithmically over time A sweep direction up or down may also be specified The user can specify a Continuous or Triggered type sweep In the Continuous mode the sweep is restarted once the stop frequency is reached In the Triggered mode the output waits at the start frequency until a trigger condition happens Triggers can
76. el To access these modes press the Mode key and then the Clear key to bring up a scroll menu from which you can select one of these extra modes 4 2 Next Cursor Field This is the most frequently used key on the 625 It is used to move the cursor to the numeric entry field that you wish to edit Each time this key is pressed the cursor is advanced to the next field on the display The cursor position is indicated by a flashing character When the cursor is advanced to a new field it is placed at the last used position within that field You then use the gt or keys to move the cursor side to side within the field One of the valid cursor fields is off When the cursor is off i e there are no flashing characters anywhere then all numeric values are frozen and cannot be changed until the cursor is switched back on This feature is designed as a lockout function to safeguard parameter values from being changed by inadvertent key presses or turns of the rotary knob 4 3 Recall Store key This key is used to store or recall an instrument setup to or from 10 storage locations in non volatile memory This saves the time of re entering parameter values for frequently used configurations The offset voltage and currently selected RS232 baud rate are also saved All parameters for a given mode are retained in memory while the 625 is powered Even if you leave one mode for another and return to the first mode the operating parameters will
77. el etc 7 When a command is selected command the 625 to generate the same number of pulses associated with the selected command A NOTE This program uses the same subroutines as those listed in Appendix A 81 i Program Start DECLARE SUB Delay X Declare functions used below l The Delay function waits x mS then returns DECLARE SUB Pause The Pause fctn waits for a keypress then returns DIM Array 5 General purpose array 1 User Entered Values By observing the signal from a remote control with an oscilloscope the following parameters were recorded To adapt this program to another remote control model change the values below CarrierFreq 32768 Type in the infrared carrier freq here this value is in Hz OnTime 30 Type in the burst on time here this value is in mS OffTime 10 Type in the burst off time here this value is in mS These variables hold the number of pulses that form each command PowerToggle 20 Turn the TV on and off twenty pulses ChannelUp 9 Go to next channel ChannelDown 12 Go to previous channel VolumeUp 3 Increase volume one notch VolumeDown 5 Decrease volume one notch 1 CLS Clear the screen This array is used as a data table which given a command menu number as an index returns the number of pulses in a given infrared pulse stream Array 1
78. el on the front panel 3 Download your data message to the 625 through the serial port see below 4 Trigger the transmission see below 5 Optionally store the instrument setup and message to nonvolatile memory Each step is described in more detail on the following pages 40 Data Modulation Mode Parameters Int FSK 1 008 Hz Mark 1 000 000 Hz Space 2 000 000 0 Hz Data 210 0 dBm TTL Cmos Zo 50Q Figure 5 25 1 Data Modulation mode display 1 Baud Rate In this field enter the frequency at which the data bits will modulate the output carrier You may enter from 0 Hz to 130 000 Hz in 1 Hz steps The baud rate frequency is accurate to 1 Hz from 0 Hz to 3900 Hz Itis accurate to within 1 across its full range of 0 Hz to 130 000 Hz 2 Mark Frequency When the modulation data bit is a 1 the output is set to the Mark frequency You may enter a frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 3 Space Frequency When the modulation data bit is a 0 the output is set to the Space frequency You may enter a frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 4 Data This word appears when a valid modulation data message has been downloaded to the 625 Without a valid data message the word Data does not appear and the 625 operates in regular Internal FSK mode 5 Level In this field enter the output level either from
79. en the Mark frequency and the Space frequency External FSK Mode Parameters The External FSK mode has the following front panel display Ext FSK Mark 1 000 000 8 Hz Space 2 000 000 0 Hz 180 0 dBm 4 7 C8 9 Dmi eg DTMF Gen SSB Function Pulse KHz ae ore Vp set 4 LS C6 Yow DTMF Det Sweep FSK B t Store 0 H Joea ESC m m gt 1 2 3 Yow s Pur noes an FM gn SYNC SIG OOO Cee Power O Arbitrar y X Sinewave Other Figure 5 10 1 External FSK mode display 1 Mark Frequency In this field enter the Mark frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps When the voltage on the Ext FSK In connector is high 3V to 10V the output frequency will be set to this value 2 Space Frequency In this field enter the Space frequency from 0 Hz DC to 20 0000000 MHz in 1 Hz steps When the voltage on the Ext FSK In connector is low OV to 10V the output frequency will be set to this value 3 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE For wideband FSK where the difference between Mark and Space frequencies is gt 1 0 MHz the output level may shift slightly between the mark and space frequencies The 625 has internal leveling circuitry which is disabled in this mode in order to offer faster FSK switching rates NOTE
80. eneration Mode Parameters Dualtone F1 10 000 Hz F2 5 000 Hz 6 123 Q Ton 180 000 mS Toff 5 908 mS 10 0 dBm Next T 7 8 9 Jul Jcursor see Field DIMF Gen SSB Function Pulse KH Mod 4 4 5 Ce is Dr pala DTMF Det Sweep FSK Burst Clee 0 H R 11 gt 1 2 3 nio eca Remote n Pavien Pwr meas AM FM M Out fJ Lal t J aoe wae O Arbitrary KO Sinewave Other TTL Cmos Zo 50Q The Dualtone Generation mode has the following front panel display Figure 5 24 1 Dualtone Generation mode display 1 Tone 1 Frequency In this field enter the frequency of the first sinusoid You may enter from 0 Hz DC to 10 000 KHz in 1 Hz steps 2 Tone 2 Frequency In this field enter the frequency of the second sinusoid You may enter from 0 Hz DC to 10 000 KHz in 1 Hz steps 3 Phase Offset In this field enter the phase offset from the first sinusoid to the second The sinusoid of Tone 1 is advanced by the specified phase relative to Tone 2 This parameter is useful when the frequencies of the two tones are harmonically related and a specific phase relationship between the two is desired You may enter from O degrees to 359 degrees in 1 degree steps 4 Output On time In this field enter the amount of time for the output to remain on If you wish a continuous output any value may be specified here but you will need to set the off time to 0 mS
81. ent format which represents a number from 1 0 to 1 0 as follows 8000 E000 FFFF 0 4000 7FFF 1 0 5 0 0 5 1 0 Although a 16 bit value is sent to the 625 the Arbitrary Waveform system uses a 12 bit D A converter so not all 16 bits are used Only the uppermost 12 bits are used to form the arbitrary waveform point Rules for Binary format 1 IMMEDIATELY after the B character in the header the 625 expects the 1 first high byte of data point 1 No whitespace is allowed after the B in Binary mode 2 The high byte of each data point is sent first followed by the low byte 3 The SYNC Out output is controlled by bit 3 in the low byte If this bit is set to 1 SYNC Out is set high If this bit is set to 0 SYNC Out is set low SendBinary IF PointNumber 1 THEN PRINT 1 WB Put header info before lst data point Must not have CR or LF after Convert the value in PointVal to a two s complement hex number j 32767 IF PointVal lt 0 THEN PointVal PointVal 2 j 32768 a INT PointVal j Convert 1 0 1 0 to 0 65535 a INT a 16 Only the uppermost 12 bits are used so a a 16 Mask off the lower 4 bits AND fff0 IF PointNumber 2 THEN a a OR amp H8 Set SYNC Out bit for second point If you let Basic send a 16 bit variable to a port it will send the low byte first and then the high byte The 625 ex
82. ff When the cursor is off the parameter values for a mode cannot be changed Turning the cursor off can be used to safeguard parameter values from being changed by inadvertent key presses or turns of the rotary knob When the cursor is moved to a field other than 0 the cursor is always positioned in the rightmost position least significant digit position of that field If a field value is entered that is out of range i e you try to set the cursor to field 7 in Sweep mode the cursor will be turned off NOTE When writing control software it is preferable to use this command to move the cursor instead of the N next cursor field or P previous cursor field commands because this command ensures that the cursor goes directly to the desired field regardless of where it was before the command was issued P Move cursor to Previous field This command functions the same as the N command Next Cursor Field except that the cursor is moved to the previous field instead of the next field If the cursor is in field 1 when this command is issued then the cursor is set to field 0 cursor off When the cursor is moved to a field other than 0 the cursor is positioned in last used position of that field NOTE When writing control software it is preferable to use the FO 9 command to move the cursor instead of the N next cursor field or P previous cursor field commands because the FO 9 command ensures that the cursor goes directly to t
83. format to expect y F Floating Point I Integer H ASCII Hexadecimal B Binary Each subroutine gives a short example of each format VKKKKKKKKKKKKKKKKKAKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK y Send Floating Point data to 625 This is the easiest format to use with Basic since no format conversion is necessary Basic will output floating point numbers by default Rules for floating point format 1 The 625 expects all floating point values to be between 1 0 and 1 0 i If a number falls outside that range the number is set to 1 0 or 1 0 These correspond to the peak values of the waveform y If the output voltage level were set for 5V p p for example then 1 0 corresponds to 2 5V and 1 0 corresponds to 2 5V across a 50 ohm load For maximum signal fidelity you should design your waveform so that the peak values just fit into the range of 1 0 to 1 0 You will then be using the full output range of the DAC 2 To separate each number you may use commas tabs spaces carriage i returns and or linefeeds semicolons colons or basically any character that is not among the following 0 1 2 3 4 5 6 7 8 9 gt e E 3 You do not have to include an exponent i e e 5 If no exponent is given the 625 assumes that the exponent is 0 4 Whitespace characters are not allowed between the mantissa and exponent 5
84. ftst DTMF Det Sw FSK st C Joasi Hz Recall Remote 5000 rieo ii SYNC SIG Poner wr meas AM FM M Out Ot SOMO clear Figure 5 4 1 Internal FM mode display 1 Modulating Frequency In this field enter the frequency of the modulating sinusoid You may enter from O Hz to 10 000 Hz in 1 Hz steps 2 Peak Frequency Deviation In this field specify the degree to which the modulating signal is allowed to change the carrier frequency You may enter from 0 Hz no change to 5 0 MHz in 1 Hz steps This parameter is a peak value If the deviation were 1 KHz and the carrier frequency were 1 MHz for example then the output frequency will swing between a maximum of 1 MHz 1 KHz and a minimum of 1 MHz 1 KHz Note If values for the deviation and carrier frequencies are entered such that the output frequency exceeds the 0 to 20 0 MHz range distortion of the output waveform may result 3 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps Note If values for the deviation and carrier frequencies are entered such that the output frequency exceeds the 0 to 20 0 MHz range distortion of the output waveform may result 4 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear a
85. full output range of the DAC 2 To separate each number you may use commas tabs spaces carriage ji returns and or linefeeds semicolons colons or basically any character 1 that is not among the following 0 1 2 3 4 5 6 7 8 9 e E 3 Use of the character for positive values is optional 4 Leading 0 s are ignored 5 To set SYNC Out high during a data point put a p or Pp 1 BEFORE that data point The P character may have whitespace around it if desired SYNC Out is set low for all data points that do not have a p or P before them Examples of integer numbers SYNC Out is set high on point 3 r 0 123 p 411 320 12 2017 2047 Send data point as Integer SendInteger IF PointNumber 1 THEN PRINT 1 WI Put header before lst data point IF PointNumber 2 THEN PRINT 1 p Set SYNC Out for second point Convert the value in PointVal to an integer that ranges from 32767 to 32767 a INT PointVal 2047 Convert 1 0 1 0 val to a 2047 2047 val PRINT 1 a Send integer value to 625 RETURN 70 Send ASCII Hex data to 625 This format sends the same two s complement data that except that each nibble 4 bits of the hex value is Binary format uses repr an ASCII character Each point is a 16 bit word which is sent to the 625 Each character represents 4 bits of the 16 bit value 0000 t
86. g Modes To select another operating mode press the blue Mode key once When pressed the LCD display is cleared and the question Mode is displayed The Mode key acts as a shift type key in that the meaning of each button on the front panel changes to that described by the blue wording beneath it To enter the SWEEP mode for example first press the Mode key and then press the number 4 key You can then use the Next Cursor Field key to move the cursor to the parameter you wish to change Each numeric value can be entered or modified in the same manner described above This manual contains a separate chapter for each mode which describes in detail all parameters on the LCD display 3 2 Selecting an operating mode If you wish to select a new operating mode for the 625 press the blue Mode key once When pressed the LCD display is cleared and the question Mode is displayed The Mode key acts as a shift type key in that the meaning of each button on the front panel changes to that described by the blue wording beneath it To enter Sweep mode for example first press the Mode key and then press the number 4 key You can exit this question either by pressing the blue Mode key again or by pressing any key that does not have blue text beneath it The 625 will then return to the current mode unchanged Some modes are available on the 625 that are not printed on the front panel To access these modes press the Mode key and then the key labele
87. g as far as getting the data sent correctly Each data point is a 16 bit word which is sent to the 625 in two bytes The high byte is sent first followed by the low byte The 16 bit value is in two s complement format which represents a number from 1 0 to 1 0 as follows 8000 E000 FFFF 0 4000 7FFF 1 0 5 0 0 5 1 0 Although a 16 bit value is sent to the 625 the Arbitrary Waveform system uses a 12 bit D A converter so not all 16 bits are used Only the uppermost 12 bits are used to form the arbitrary waveform point The fourth lowest bit bit 3 is sent directly to the SYNC Out connector on the front of the 625 Example The data value E468 is handled as follows E 4 6 8 Aaa arre a et 112 la bo These 12 bits are sent to the DAC O This bit is sent to the SYNC Out Connector Rules for Binary format 1 IMMEDIATELY after the B character in the header the 625 expects the first high byte of data point 1 No whitespace is allowed after the B in Binary mode 2 The high byte of each data point is sent first followed by the low byte 3 The SYNC Out output is controlled by bit 3 in the low byte If this bit is set to 1 SYNC Out is set high If this bit is set to 0 SYNC Out is set low Example A 10 point waveform in binary format with SYNC Out set high point 3 This is the same waveform data that is given as an example in the Hexadecimal format section W B lt 00 gt lt 00 gt lt
88. get a 800 mS Rx char time out Returns with a received stuff 1 GetResponsel IF LOC 1 0 THEN GOTO GetResponsel Wait for incoming char a o GetResplLoopl aS a INPUTS LOC 1 1 Get all waiting chars in Rx buffer Now wait for a time out time to make sure no new stuff is coming in CALL Delay 8 Do a 800 mS delay IF LOC 1 lt gt 0 THEN GOTO GetResplLoopl If something came in during our time out grab it RETURN j Wait for a command prompt from 625 Returns AS all stuff received before the command prompt PromptWait If we have no chars in Rx buffer wait until we have 1 or more as ww PromptWaitLoop IF LOC 1 0 THEN GOTO PromptWaitLoop aS a INPUTS LOC 1 1 Get all waiting chars in Rx buffer IF INSTR a gt THEN GOTO GotPrompt GOTO PromptWaitLoop Here we got a prompt Exit GotPrompt RETURN Flush all Rx chars from Port 1 buffer 79 FlushBuffl IF LOC 1 O THEN GOTO DoTimeoutl aS INPUTS LOC 1 1 Get all waiting chars in Rx buffer Now wait for a time out time to make sure no new stuff is coming in DoTimeoutl CALL Delay 8 Do a 800 mS delay IF LOC 1 lt gt 0 THEN GOTO FlushBuffl If something came in during our time out flush it RETURN y Wait for x mS Function to delay x number of mS SUB Delay X STATIC start TIMER Returns no of secs since m
89. gger Ext Gating Ref In RS232 n 10 Mhz Zin gt 3 KQ TTL CMOS Level 10 dBm Interface User Data 3 to 10V 0 to TIO V Figure 2 0 4 Driving the Ext Trigger Gating FSK BPSK input On this connector the user supplies a digital signal which serves a variety of purposes depending on the operating mode of the 625 This input is a high impedance input about 80K ohms and can safely accept input levels from 10V to 10V The input uses a comparator with a switching point of about 1 4V permitting either TTL or CMOS logic to drive this input The input has hysterisis too so you can apply analog signals to this input 1 e a sinewave This input has an internal pulldown resistor which holds it in the low or 0 state when left open In most modes this input can be used to switch the output signal on or off When driven high the output signal is gated off This function can be performed up to 3 MHz When the output is gated off the DC level on the Sig Out jack is unpredictable The Gating input freezes the output waveform at the output voltage is held to the voltage value that existed at the moment the Gating input went high When the Gating input is brought low again the output waveform resumes from the same point In the External FSK and BPSK modes this input is used to bring in digital data for FSK or BPSK modulation In the Burst and Triggered Sweep modes this input is used as a trigger
90. haracters KO To re enable them issue the characters K1 On power up the keypad rotary knob and RS232 port are all enabled and operate together simultaneously If the front panel is not needed during remote operation it is advisable to disable it with the KO command This would prevent a user from pressing buttons on the front panel of the unit which could upset a control program by unexpectedly changing the state of the 625 E1 0 Enable Disable LCD echo to terminal This command enables or disables a feature where the 625 prints the contents of the LCD display to the terminal port whenever the display changes It is useful to enable this feature when you cannot see the LCD display It is also used by the point and click Remote Control Software for Windows The command echoes the LCD display by sending two lines of ASCII text containing all 80 characters of the display Two lines of 40 ASCII characters are always printed even if a line on the display is blank Each line is enclosed by the double quote character and each line begins and ends with a carriage return and linefeed sequence The location of the cursor within the display is also reported as a hex value A typical LCD display echo in Sinewave mode for example would appear on a terminal as follows Cursor 4B Sinewave mode gt 1 000 000 0 Hz 10 0 dBm The cursor positions for the top line of the display begin with O for the upper left corner and end with hex
91. he desired field regardless of where it was before the command was issued orH Print help menu This command prints the on line help menu The menu is a listing of all remote control commands To issue this command you may press either the H or the keys on your terminal E Returna C Sending an ASCII control E character ASCII value 5 to the 625 will cause it to echo back a control C ASCII value 3 This feature can be used by remote control programs to confirm the presence of and successful communication with the 625 49 6 7 Remote Control Examples The following are some examples of ASCII character command sequences Example 1 MO F1 3 1412 N 2 32 FO Note You do not need spaces between the characters They were added here only to make the commands more readable This command sequence breaks down as follows MO Set 625 to Sinewave mode F1 Move cursor to field 1 frequency field 3 141Z Enter a freq value of 3 141 MHz N Move cursor to next cursor field field 2 level field 2 32 Enter a level of 2 3 dBm FO Move cursor to field 0 turn cursor off Example 2 M6 Fl 0 F2 432X F3 5z 4 10y f0 O 1 23Y T Note All commands are case insensitive you may use either upper case or lower case letters This command sequence breaks down as follows M6 Set 625 to Burst mode Fl Move cursor to field 1 Trigger Continuous field 0 Set Triggered burst mode F2 Move cursor to field 2 on time duration field
92. ic high 3V to 10V on this jack The output frequency will be held constant until the input is brought low again The sweep will then resume toward the stop frequency In Triggered type sweep this input functions as an external sweep trigger input A logic low to high transition on this input will trigger the sweep This input has an internal pulldown resistor so that the input is held at a logic low when this input is left unconnected 22 5 9 Internal FSK Mode Introduction The Internal FSK mode generates a frequency shift keyed signal of fixed amplitude An internal timer is used as a modulating signal to toggle the output frequency between the Mark frequency and the Space frequency at a specified rate Internal FSK Mode Parameters The Internal FSK mode has the following front panel display O Int FSK 1 000 Hz ark 1 000 900 0 Hz O pace A is z 10 m S 2 0008 000 0 H 10 0 dB 5 Next T Lt 7 C8 9 ope Cursor E DTMF Gen SSB Function Pulse KHz ode OOO Oe Bs o DTMF Det Sweep FSK Burst Store Figure 5 9 1 Internal FSK mode display 1 Modulating Frequency In this field enter the frequency at which the output will switch between the Mark and Space frequencies You may enter from 0 Hz to 130 000 Hz in 1 Hz steps The internal modulating frequency is accurate to 1 Hz from 0 Hz to 3900 Hz It is accurate to within 1 across its full range of 0 Hz to 130 000 Hz
93. ided 53 7 3 Switching Modes Switching to Arbitrary Waveform Function Generator Pulse Generator Mode To change to one of these modes press the blue Mode key once When pressed the LCD display is cleared and the question Mode is displayed Then press the key to activate the Arbitrary Waveform modes menu Select 1 Arbitrary Waveform 3 Pulse Gen 2 Function Gen Press 1 to enter the Arbitrary Waveform Mode Press 2 to enter the Function Generator Mode Press 3 to enter the Pulse Generator Mode You may also switch to Function Generator mode by pressing Mode then 8 You may switch to Pulse Generator mode by pressing Mode then 9 You can exit this question without changing the mode by pressing the blue Mode key twice or by pressing any non valid menu selection The 625 will then return to the current mode unchanged 54 7 4 Arbitrary Waveform Mode The Arbitrary Waveform mode has the following front panel display Arbitrary Waveform Mode Cont Clk Freq 40 000 000 0 MHz 10 0 dBm TMF Ge TMF De SIG wr mea Out S ee Clear YH Arbitrary x Sinewave TTL Cmos Zo 50Q Figure 7 4 1 Arbitrary Waveform Mode display 1 Continuous Triggered mode In this field select whether the waveform is generated continuously or on a single event basis If you select Continuous mode then the waveform is immediately restarted once the last poin
94. idnight Example 65445 15 DelayLoop Do a x mS delay IF TIMER lt start X 1000 THEN GOTO DelayLoop END SUB f Wait for a keypress SUB Pause STATIC DO LOOP UNTIL INKEYS lt gt Wait for keypress to continue END SUB 80 Appendix B Television Remote Control Example This chapter contains an example program written in Microsoft Quickbasic for controlling the 625 remotely It is used here to drive an infrared LED to issue commands to a TV or a VCR It uses the 625 in Burst mode to emulate the same waveforms used in many infrared remote control transmitters Background Many TV remote controls operate by flashing an infrared LED at a carrier frequency rate in the ultrasonic frequency band usually 30 40 KHz Short bursts of these pulses are used to form various remote control commands to command the TV power on or off change the channel etc Often it is the number of bursts which determines which command is which Some TV s and VCR s count the number of pulses to distinguish between commands The pulse sequence for a TV receiver was determined by examining the signal generated by the remote control unit An oscilloscope was used to observe the waveform across the remote transmitter s LED Using the oscilloscope the carrier frequency pulse on time pulse off time and number of pulses for several commands was measured These parameters were then entered into the Basic program The Basic prog
95. in cable CA E gt 6 Ss To F P pe PC of3 to aE To kira 7 Re 5 5 9 pin 25 pin cable Note Any additional wires between the two connectors is optional 2 Apply power to the 625 After a display of the hardware and software versions and serial number the unit enters the Basic Sinewave mode of operation 3 Run the program WAVELOAD EXE which is on the enclosed floppy disk You may run this program from the Windows95 START RUN menu or from the DOS prompt The program will ask you which serial com port the 625 is attached to Please select a serial port 1 COM1 2 COM2 3 COM3 4 COM4 Enter selection 1 2 3 4 gt After you enter a com port number the program will next ask you for the type of data you are sending to the 625 Please select a file type F Floating Point T Time amp Value Floating Point CSV PRN D Digital H Hexadecimal I Integer B Binary N Do not send a header Enter selection F H I B N gt Enter F to indicate a floating point file Next you will be asked for the filename Enter filename ESC to exit gt Enter A ARB EXAMPLES SINE FLT and hit the ENTER key Note A quicker way to do the above is to enter all parameters on the command line For example if com port is 2 WAVELOAD COM2 F arb examples sine flt For further details see the chapter on using WAVELOAD EXE 4 Press the blue MODE key once then the key and 1 to switch to Arbitrary Waveform
96. ired digit use the 48 or Y key to increment or decrement that digit Pressing the A key increments the digit under the cursor and has the same effect as rotating the knob clockwise 1 tick Pressing the WV key decrements the digit under the cursor and has the same effect as rotating the knob counter clockwise 1 tick While a numeric value is being typed in you can use the key as an erase key Pressing this key erases the last digit entered allowing you to correct typing mistakes All arrow keys have an auto repeat feature By holding down the key the key will repeat continuously until released This makes it more convenient to quickly sweep a value or move the cursor within a field These keys are also used to select a new operating mode after the Mode key is pressed The arrow keys are then used to select the mode indicated by the blue text beneath the key In DTMF Generation mode these keys specify DTMF digits A B C D which are signaling tones used in the telephone network but not found on a typical telephone For more information refer to the chapter on DTMF Generation mode 4 8 Clear key While the cursor is within a numeric field the Clear key erases all digits within the field allowing the user to start over when entering a value This key is also used to select the Other mode after the Mode key is pressed once By selecting Other Mode a menu of extended modes for the 625 is presented See the chapter on Changing Modes
97. l Wait for and get response from 625 to a GetCommand 83 CLS PRINT PRINT PRINT 1 Power on off PRINT 2 Channel Up PRINT 3 Channel Down PRINT 4 Volume Up PRINT 5 Volume Down PRINT PRINT ESC To exit program PRINT PRINT Please select a command gt CommandPoll aS INKEYS IF aS THEN GOTO CommandPoll IF aS CHR 27 THEN SYSTEM Exit the program on ESC keypress IF a lt 1 OR aS gt 5 THEN GOTO GetCommand Is input valid PRINT PRINT PRINT Command sent Tell user command will be sent a VAL aS Convert selection to a number 1 to 5 NumPulses Array a Look up no of pulses for this command The variable NumPulses now has the number of infrared pulses to form this remote control command Download this many t characters to the 625 which causes it to trigger that many pulses in Burst mode aS STRINGS NumPulses t Form a string with NumPulses number of t chars in it I e if Numpulses 3 then aS ttt PRINT 1 aS Dump the t s to the 625 The 625 will now trigger a burst for each t char we sent it After the 625 executes each t command it will return a prompt character gt We wish to wait until after all prompts have come in since that s when the 625 has finished processing the last t The GetResponsel subroutine has a time out feature which will accomplish this purpose GOSUB GetResponsel Wait
98. ll appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 29 5 17 DTMF Detection Mode Introduction The DTMF Dual Tone Multi Frequency Detection mode decodes and displays the Touchtone dialing tones for the American telephone network Signals to be decoded are applied to the External Mod In jack Once a DTMF digit has been detected it will appear on the LCD display and will also be sent to the RS232 terminal port The input signal must be 10 Vp p or less If the input signal exceeds 10 Vp p the waveform will distort and adversely affect the DTMF detector Input levels above 50 Vp p may damage the 625 The DTMF detector in the 625 features an AGC algorithm which boosts low level signals 20 mVp p or greater to detect low level DTMF tones For reliable detection each DTMF digit must be present for a minimum of 100 mS There must also be a minimum silent period of 100 mS between each DTMF digit The Ext Mod In input is high impedance about 30K ohms If your system expects this signal to be terminated place
99. lready has the W M header you may use the WAVELOAD EXE utility with the no header option N to send the file to the 625 See the chapter on Downloading Arbitrary Waveforms for more information on WAVELOAD EXE You may also write your own program to send the data to the 625 If you wish to use your own program be sure to set the serial port parameters tol start bit 8 data bits 1 stop bit and no parity The baud rate of your program must also match that of the 625 To inspect or change the 625 s baud rate press the Mode key and then the Offset key Modulation Data is sent to the 625 in Hexadecimal format For more information on hexadecimal numbers refer to the chapter on Hexadecimal Format in the Arbitrary Waveform Mode section of this manual The message consists of a two character header a bit count word and the modulation data words It does not matter what mode the 625 is in when the data is downloaded however you must switch to Internal FSK mode in order to transmit the message Example Message The message is best explained by example An example message is W M 0012 FE96 AA20 X which breaks down as follows W This is the first character which tells the 625 to download data from the user M This character tells the 625 that the data is MODULATION data as opposed to an arbitrary waveform 0012 This is the bit count In this case the message is 18 bits long 0012 in Hexadecimal is 18 in base 10 FE96 This is
100. mbers You may also turn the wheel to scroll the menu forward or backward To select a mode listed in the menu press its number key To abort the menu and return to the previous mode press any key other than an arrow or 0 to 9 35 5 22 Internal BPSK Mode Introduction The Internal BPSK mode generates a phase shift keyed signal of fixed amplitude An internal timer is used as a modulating signal to switch the output phase between 0 and 180 degrees at a specified rate The modulation is suppressed carrier i e no carrier energy is present in the output waveform This mode is available under the other modes menu To enter the Internal BPSK mode press Mode Clear 1 1 Internal BPSK Mode Parameters The Internal BPSK mode has the following front panel display O Int BPSK 1 000 Hz O 1 000 000 Hz 18 8 dBm Next T Mh t 7 8 9 Jape cursor R DIMF Gen SSB Function Pulse 0 KHz Mod OOOO Ot o DTMF Det Sweep FSK Burst ea Hz Recall R gt 1 2 3 LJ ae 7 Bower Pwr meas an FM an cae Ste f J lt jJtaji J JClear Arbitrary X Sinewave Other TTL Cmos Zo 58Q Figure 5 22 1 Internal BPSK mode display 1 Modulating Frequency In this field enter the carrier phase switching frequency You may enter from O Hz to 130 000 Hz in 1 Hz steps The internal modulating frequency is accurate to 1 Hz from 0 Hz to 3900 Hz It is accurate to within 1 across its full rang
101. mode The 625 will then generate the waveform at the selected clock rate and output level If you wish to change these parameters use the Next Cursor Field key to move the cursor to the desired field so that you may modify the value or type in a new value 51 7 2 Introduction to the Arbitrary Waveform Mode 7 2 1 Description of the Arbitrary Waveform Mode The Arbitrary Waveform Mode lets the user design custom waveforms on a PC and download them to the 625 for generation The Arbitrary Waveform system makes possible a fully featured Function Generator The function generator offers a set of pre stored waveforms which are generated using the Arbitrary Waveform hardware The user may select from many stored waveforms and may also specify a repetition rate to 2 MHz All functions may be generated on a continuous or triggered basis A high going pulse is given on the SYNC Out connector at the start of each waveform Also included with the Arbitrary Waveform system is a variable duty cycle Pulse Generator The Pulse Generator allows the user to generate pulse waveforms with varying amplitude offset frequency and duty cycle The pulses may be generated on a continuous or triggered basis Introduction An Arbitrary Waveform is generated by sending values to a Digital to Analog converter DAC from a ram memory A high speed counter generates sequential addresses which indexes successive ram values for the DAC The clock for the counter is derived f
102. n amount of time A log sweep means that the frequency is adjusted logrithmically between the start and stop frequencies as the sweep progresses To set Linear type sweep press 1 To set Log type sweep press Q Pressing any arrow key or rotating the wheel will toggle the sweep type between Linear and Log 21 4 Continuous Triggered sweep In this field select whether the sweep is performed continuously or on a single event basis If you select a Continuous sweep then the sweep is immediately restarted once the stop frequency is reached If you select a Triggered type sweep then the sweep is halted once the stop frequency is reached The sweep is not restarted again until another trigger occurs The trigger can come from three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trig In connector 3 Sending an ASCII T to the RS232 port The 625 will simultaneously accept a trigger from all of the above sources To set Continuous type sweep press 1 To set Triggered type sweep press 0 Pressing any arrow key or rotating the wheel will toggle the sweep type between Continuous and Triggered 5 Up Down sweep In this field select the direction of the sweep An up sweep begins at the start frequency and ends at the end frequency A down sweep begins at the end frequency and ends at the start frequency To set Up type sweep press 0 To set Down type sweep press 1 Pressing any arrow key or rotating th
103. n example waveform in floating point format This file is on the supplied floppy disk in the arb examples directory 1 Connect a serial port on you PC to the serial port connector on the rear of the 625 You may temporarily detach your serial mouse if needed to free up a serial port Mouse operation will be restored after the download If your computer has a 9 pin connector use a cable that is wired 1 1 or straight through If you computer has a 25 pin serial port connector install a 25 to 9 pin adapter available at most computer stores and then the 1 1 wired cable If you wish to build your own cable wire it as follows 9 pin 9 pin cable 9 pin 25 pin cable EN MN SS ee To D 625 4 o PES a EL 5 5 i Note Any additional wires between the two connectors is optional io ES 2 Apply power to the 625 After a display of the hardware and software versions and Fe serial number the unit enters the Basic Sinewave mode of operation 3 Run the program WAVELOAD EXE which is on the enclosed floppy disk in the ARB directory You may run this program from the Windows95 START RUN menu or from the DOS prompt The program will ask you which serial comm port the 625 is attached to Please select a serial port 1 COM1 2 COM2 3 COM3 4 COM4 Enter selection 1 2 3 4 gt After you enter a com port number the program will next ask you for
104. nction to generate a new point value a value from SIN which ranges from 1 0 to 1 0 your own function here from 1 0 to 1 0 since the subroutines below to range from 1 0 to 1 0 PointVal SIN Phase Pick one of the following subroutines depending on desired data format GOSUB SendFloat Send Floating Point ex GOSUB SendHex Send Hexadecimal ex GOSUB SendInteger Send Integer ex GOSUB SendBinary Send Binary Phase Phase PhaselInc NEXT PointNumber X All points have now been generated and When the 625 hasn t received any chars 1 second time out it assumes that all generating the waveform ArbExit CLOSE SYSTEM E 68 Continue loop and generate more points sent to the 625 over the serial port for a points have been sent and starts Close the comm port and exit the program UV KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK i Subroutines These subroutines take a value in PointVal which ranges from 1 0 to 1 0 and converts it to various data formats i e Floating Point Binary ASCII Hex and Integer and then sends that value to the 625 Before the first data point is sent a Header consisting of two characters is sent to the 625 The first character of this header is a W which tells the 625 to expect arbitrary waveform data points The second r character of the header tells the 625 what data
105. nd O 1 009 000 0 Hz 10 0 dBm Next T t r e la Jaga C eursar ET 5 DTMF Gen SSB Function Pulse KH Mod OMB Oe ws DTMF Det Sweep FSK Burst aes H R 11 gt 1 2 3 nino A A Power Pwr meas AM FM M Te are i L J C JL Clear O Arbitrary Sinewave Other TTL Cmos Zo 50Q Figure 5 12 1 Internal SSB mode display 1 Modulating Frequency In this field enter the frequency of the modulating sinusoid You may enter from 0 Hz to 1 MHz in 1 Hz steps Note It is possible to enter values for the modulating and carrier frequencies such that the upper sideband can exceed 20 0 MHz or the lower sideband can go below 0 Hz Care should be taken not to do this since distortion of the output waveform will result 2 Upper Lower Sideband selection This parameter selects which sideband will be generated Single sideband modulation specifies that all energy in the modulated waveform should be either above the carrier frequency or below it Upper sideband places all signal energy above the carrier frequency and Lower sideband places all signal energy below the carrier frequency To select Lower sideband press 0 To select Upper sideband press 1 Pressing any arrow key or rotating the wheel will toggle the sideband selection between Upper and Lower 3 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps Note It is possible to enter values for the modul
106. nd is optional If the x character is missing the 625 will assume all data has been sent after 1 second timeout 61 7 8 3 Digital Format The Digital format was implemented as an easy way to design purely digital waveforms i e waveforms that are either high or low The digital format provides a very efficient way of representing waveforms that assume only a high or low value If the value of the data point is 0 then the SIG Out output is set to its minimum negative output voltage and the SYNC Out output is set to the logic Low state OV for that point If the value of the data point is non zero then the output is set to its maximum positive output voltage and the SYNC Out output is set to the logic High state 5V for that point All rules for this format are identical to those for Floating Point Format except that the Time or Point Number value need not be between 1 0 and 1 0 in value since the 625 only sees if the value is zero or nonzero Also the P character has no meaning since the SYNC Out output is controlled by the data itself With this format it is possible to specify each point of a digital waveform with only two bytes a 1 or a O and a data separator character This makes this format as efficient as binary format for data downloads However since the data consists entirely of ASCII characters it is easier to work with than binary format Example This twelve point digital waveform 01001100011
107. nusoid The modulation waveform is not suppressed carrier i e a fixed amount of carrier power is always present in the modulated signal External AM Mode Parameters The External AM mode has the following front panel display External AM Input gain 999 O 1 000 000 0 Hz PEP level 18 8 dBm k t r l 8 8 9 Jun ME 5 DTMF Gen SSB Function Pulse KH 4 4 5 6 Js I gt Offset ec DTMF Det Sweep FSK B urst St Hz Recall gt 1 03 L Ji Oe SYNC SIG Poner Pwr meas AM FM gn Out Out CS EC Ce E L Joe O Arbitrary X Sinewave Other TTL Cmos Zo 50Q Figure 5 3 1 External AM mode display 1 Input Gain In this field specify a value used to scale the input signal With a value of 999 a 1 Vp p signal on the input will result in 100 modulation of the carrier amplitude You may enter a value from 0 to 999 The gain value is always less than 1 0 To enter a value type 1 to 3 numeric digits If you type 3 digits the value is automatically entered If you only type 1 or 2 digits you can press the MHz key or the KHz key or the Hz key all are equivalent to enter the gain value 2 Carrier Frequency In this field enter the frequency of the carrier from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 3 PEP Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE
108. o 1001 Represented by an ASCII 0 to 9 1010 Represented by an ASCII a or A 1011 Represented by an ASCII b or B 1100 Represented by an ASCII c or C 1101 Represented by an ASCII d or D 1110 Represented by an ASCII e or E 1111 Represented by an ASCII f or EF For example the 16 bit value 1101 0011 0101 1111 is sent The 16 bit value is in two s complement format from 1 0 to 1 0 as follows 8000 E000 FFFF 0 1 0 2 0 0 Although a 16 bit value is sent to the 625 uses a 12 bit D A converter 12 bits are used to form the arbitrary waveform point Rules for Hexadecimal format sented by with 4 characters as d35f which represents a number the Arbitrary Waveform system so not all 16 bits are used Only the uppermost 1 Each Hexadecimal value may have 1 to 4 characters 4 characters since the most significant bit of the value must be a 1 for negative values If there are fewer than value is interpreted as positive 2 To separate each number you may use commas and or linefeeds semicolons among the following 0 oL 2 BA AAA MAS a tabs A b gt Bo ve E sd Db 3 The most significant nibble character is the first that 625 For example to send the value 1234 the 1 is sent the 2 etc 4 The SYNC Out output is controlled by bit 3 in the low is set to 1 If this bit is set is set low SYNC Out is set high Example
109. ode the user may set this output high or low on any data point s in the Arbitrary Waveform This feature may be used to create a pattern of logic pulses or a triggering or synchronizing signal which accompanies an analog waveform In the Function Generator mode a high going pulse is given on this output at the start of each function waveform This useful feature allows the user to synchronize the functions to other events In the Pulse Generator mode this output follows the SIG Out signal The signal on this output has the same frequency and duty cycle as signal on the SIG out connector However the signal on this connector is not variable in amplitude and offset it always swings from OV to 5V and provides a convenient interface with digital logic 2 SIG Out connector This is the main signal output It has a source impedance of 50 ohms and can supply signals as large as 10 000 Vp p into an open circuit or 5 000 Vp p into a 50 ohm load It can also supply a DC offset voltage of 8 000 V into an open circuit or 4 000V into a 50 ohm load Caution Although the output is protected against short circuits you should NEVER connect SIG Out to a voltage or signal source This may overload the output and damage the 625 3 External Modulation In connector The External Modulation In connector located on the rear of the 625 accepts an external analog signal as illustrated here Rear Panel Ext Ext Trigger Ext Mod SA inS
110. of bytes per data point and can therefore be downloaded faster A complete listing of ARB BAS begins on the following page The source file for this program can also be found on the accompanying floppy diskette 66 Program Listing ARB BAS UT KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKAKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK 1 BNC Model 625 i Vk ue Arbitrary Waveform Data Generator Example A T VT KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK Program Description This program generates a sinewave and downloads the data points to the 625 for generation with the Arbitrary Waveform system It can generate the data in a variety of different number formats Each format has its own subroutine below Open the serial port for communication with the 625 Ask the user which serial port is attached to the 625 INPUT Is the 625 on Com port 1 or 2 1 2 gt aS Open Com port Disable CD CTS DCD give 5 sec max to open y Set Rx buffer to 2K Disable RTS set Tx buff to 1K Random i o Set random access buffer size to 2K IF a 1 THEN OPEN COM1 9600 n 8 1 CD0 CS0 DS0 OP5000 RB2048 RS TB1024 FOR RANDOM AS 1 LEN 2048 GOTO EndPortSel END IF IF a 2 THEN OPEN COM2 9600 n 8 1 CD0 CS0 DS0 0P5000 RB2048 RS TB1024 FOR RANDOM AS 1 LEN 2048 GOTO EndPortSel END IF GOTO ArbExit Abort program if neither Coml nor Com2 was sel
111. ot see this menu check the following e On the 625 press Mode then Offset and verify that the baud rate is set to 9600 e Verify that you are using the correct com port e Check your cabling If you see the command menu you have verified that the 625 is properly cabled to the computer and that you are certain which com port you are using 45 46 6 4 Remote Control Operation Each key on the front keypad of the 625 has an associated ASCII character which when sent to the 625 over the serial port has the same effect as pressing that key on the keypad At power up the 625 s RS232 baud rate is recalled from stored configuration 0 The factory default for this is 9600 baud The remaining serial port parameters are always start bit 8 data bits 1 stop bit and no parity The serial port on the controlling computer must be set to match these values 6 5 Remote Control Programming Rules The following guidelines should be observed when writing control software for the 625 1 All ASCII commands are case insensitive i e upper and lower case letters are treated equally by the 625 2 When the 625 has finished executing a command it will return a command prompt which is the gt character The control software should clear its receive buffer issue a command and then look for the gt character to determine when the command has been executed If a long string of commands is sent to the 625 a separate gt character will b
112. pects the high byte first so we must reverse the two so we get the proper byte order i e high byte then low byte high INT a 256 Get the High byte of the 16 bit value low a MOD 256 Get the Low byte of the 16 bit value a low 256 high Switch hi and low bytes IF a gt 32767 THEN a a 32768 Make it signed for conversion to int bs a Convert to a 16 bit variable type PUT 1 b Write low byte then hi byte to file RETURN 72 8 0 DC Operation Option Description The DC Operation Option allows the user to power the 625 from a DC voltage source in the 9 36 VDC range The user may easily switch between the AC Line supply and a DC source This option is most useful for service and remote applications where AC power is not available A 20 72V input voltage range is also available Please contact BNC for availability Specifications e Input Voltage Range 9 36 VDC e Max Power Consumption 15 W e Switching Frequency 200 KHz e Isolation Voltage 500 VDC Wiring Diagram 9 36 VDC DC to DC Converter Ci To Power Input Caution Be certain to observe proper polarity of the input voltage connection Permanent damage may result from reversal 73 9 0 Specifications Main Output Frequency DC to 20 0000000 MHz 1 Hz steps Level 2 mVp p to 5 000 Vp p 1 mV steps into 50 Q or 50 0 dBm to 18 0 dBm 1 dBm steps into 50 Q Level Accuracy 1 Flatness 2 d
113. press the MHz key for MHz or the KHz key for KHz or the Hz key for Hz The unit will make a double click sound to indicate that a new frequency value has been accepted To modify an existing value use the gt and keys to position the cursor over the digit you wish to change Then press the AN or Y key to increment or decrement that digit Alternatively you can turn the rotary knob clockwise or counterclockwise to adjust the digit s value Changing Level To set a new output level press the Next Cursor Field button until the cursor flashes on the right hand side where the level is displayed You can change the level two ways You can type in a new value or adjust it with the wheel or arrow keys To enter a new level type in the new level value using the numeric keypad For a negative dBm value press the key while entering the value Finally press the dBm key to enter the value as dBm or the Vp p or mVp p keys to enter the new value as a peak to peak voltage Note The level you re entering here is considered a LOADED level i e the level that will appear across a 50 ohm load connected to the output To modify an existing level value use the gt and keys to position the cursor within a field Place the cursor over the digit you wish to change and press the or Y key to increment or decrement the digit Alternatively you can turn the rotary knob clockwise or counterclockwise to adjust the digit s value Changing Operatin
114. r upper or lower case at the end of your data This character tells the 625 that the end of the data has been reached The 625 will then begin generation of the new waveform immediately The X character cannot be used with the Binary format Make sure that there are no interruptions exceeding 1 second while downloading a waveform else the 625 will time out and end the download Also if you do not have an X character at the end of your data then you must stop sending characters to the 625 for a minimum of 1 second so that the waveform will be generated An example program ARB BAS is included on the supplied floppy which demonstrates downloading waveforms in a variety of formats directly from the program to the 625 59 7 8 Data Formats 7 8 1 Floating Point Format A floating point number consists of a mantissa and an optional exponent Downloading floating point values is slower because it can take many characters to represent a single numeric value This format has an advantage however because it is so flexible Many sources of data BASIC trig functions spreadsheets digital oscilloscopes and waveform design packages can generate data in this format Rules for Floating Point format 1 The 625 expects all floating point values to be between 1 0 and 1 0 If a number falls outside that range the number is set to 1 0 or 1 0 These correspond to the peak values of the waveform If the output voltage level were set for
115. ram takes these parameters and issues commands to the 625 to generate the same pulse train using the Burst mode of operation A program menu asks the user which command to generate Hardware Setup You must connect a serial cable between your computer and the RS232 port connector on the rear of the 625 For more information on how to do this refer to chapter 6 0 The program assumes you are using serial port 1 COM1 If you are using another serial port change the OPEN COM 1 statement in the beginning of this program It also assumes that the 625 baud rate is set to 9600 To check the 625 baud rate press the Mode then Offset keys You must also wire the output of the 625 to an infrared LED The diagram below shows how to do this Don t forget to aim the LED towards the device you wish to control on 390 Infrared G100 o X SYNC Out A SEA Connector 4 LED Aim toward television Figure B 1 Infrared LED hookup This program does the following 1 Clear the screen 2 Open the serial communications port for communicating with the 625 Make sure there is a 625 connected to the serial port If we can t find one wait until it is connected up Command the 625 to enter Burst mode 5 Set up the burst frequency on time and off time On time is the burst duration off time is the burst delay 6 Present a menu to the user asking which remote control command to issue 1 e power on off change chann
116. rbitrary waveform data F Floating point T Time amp Value Floating point CSV PRN D Digital H Hexadecimal Integer B Binary N Send no header Use this switch if your data file already has the two character header baud z Specifies the baud rate If this switch is omitted the baud rate defaults to 9600 The allowable baud rates are 300 1200 2400 4800 9600 19200 38400 57600 115200 filename ext The name of the file containing the arbitrary waveform data You may have a full pathname here NOTE To run WAVELOAD you must specify the COM port file format and filename If any or all of these are omitted from the command line WAVELOAD will ask you for them EXAMPLE Download the file SINE FLT which is in floating point format to the 625 using the COM1 serial port at 9600 baud WAVELOAD sine flt f coml baud 9600 58 7 7 2 Using your own program You may use your own application program to send the arbitrary waveform data to the 625 To download a waveform to the 625 you need to send the following to the 625 through the serial port 1 A two character header consisting of a The W character This tells the 625 to expect the download of an arbitrary waveform b A single character which specifies the data format The character may be F for floating point or decimal format T for time amp value floating point format D for digital format H for hexadecimal forma
117. remain unchanged If the 625 is turned off and on again however all parameters for all modes are reset to default values By using the Store Recall function you can save all operating parameters so they can be quickly recalled even though the unit had been switched off or unplugged To store an instrument setup press the Store Recall key once The LCD display will be cleared and the question Recall 0 9 will appear asking you to press a numeric key 0 to 9 to select one of ten available locations to use You can abort this question without saving a configuration by pressing any key other than 9 to 9 If you then press the 5 key for example the display will show Configuration recalled from location 5 to confirm the recall operation To save and instrument setup press the Store Recall button twice The LCD display will be cleared and the question Store 0 9 will appear asking you to select one of ten available locations to store the configuration You can abort the question without recalling a configuration by pressing any key other than 0 to 9 Note Location 0 is special The instrument state stored to location O will be recalled on power up This includes the serial port baud rate 11 4 4 Offset key The Offset key is used to specify a DC offset voltage to be added to the output signal When this key is pressed the LCD display is cleared and the cursor is placed in a numeric field to enter the offset voltage Both positiv
118. rom the same DDS system used to generate the DC 20 MHz output of the 625 Because the Arbitrary waveform system uses the fully synthesized DDS system for its clock the arbitrary waveform generator has a highly accurate and stable clock source adjustable from DC to 40 MHz in 1 Hz steps DDS DC 20 MHz Freq Clock Doubler Generator DC 40 MHz clock 9th Order Bessel Fc 10 MHz Counts 0 1 N 0 1 32K x 16 Low Pass Gain Filter Control SIG Out Front Panel Counter Extra Data bit iS TTL CMOS SYNC Out Buffer Front Panel Figure 7 2 1 1 Arbitrary Waveform Generator block diagram A logic level output is provided on the SYNC Out connector which allows the user to assert a digital pulse on any data point This can be useful to generate logic pulses which are synchronous with the analog data or to generate arbitrary digital waveforms The 625 receives arbitrary waveform data through the serial port on the rear of the 625 An incoming waveform is stored in successive ram locations beginning at address 0 After the last data point is received the system processor adds a special end of data bit to the last data point instructing the counter hardware to reset to the waveform start address after the last data point is sent to the DAC These waveform values can be sent to the 625 in a variety of formats ASCII formats include floating point time amp value floating point decimal hexadecimal
119. s of ASCII hex numbers Negativ spaces colons or basically any character that is not byte 9 0 values requir bit 15 4 characters the Characters are not case sensitive carriage returns es ESE E is sent to the first then If this bit SYNC Out SYNC Out is set high on point 3 0 4000 fed8 4570 8000 fff0 E6DO 10 FF C06 SendHex IF PointNumber 1 THEN PRINT 1 WH Put header before lst data point Convert the value in PointVal j 32767 IF PointVal lt 0 THEN PointVal to two s complement hex PointVal 2 j 32768 r to hexadecimal ie SFFFF FFD8 a INT PointVal j Get a number 0 to 65535 a INT a 16 Mask off lower 4 bits SFFFO a a 16 IF PointNumber 2 THEN a a OR amp H8 Set SYNC Out bit for second point aS HEXS a Convert the integ For negative values the HEXS fctn will return a 32 bit value so chop off all but the last 4 chars IF a lt 0 THEN aS RIGHTS a 4 PRINT 1 a Send hex point to 625 RETURN 71 i Send Binary data to 625 This is the fastest way to send points to the 625 since it transfers the data point with only 2 characters It is also the least forgiving as far as getting the data sent correctly Each data point is a 16 bit word which is sent to the 625 in two bytes The high byte is sent first followed by the low byte The 16 bit value is in two s complem
120. s waveform in memory Although mode parameters such as Clock Frequency Level etc can be saved to nonvolatile memory the arbitrary waveforms themselves are lost when the 625 is switched off Arbitrary Waveforms are also overwritten by the Function Generator and Pulse Generator modes which use the Arbitrary Waveform memory for waveform generation Note Switching to Function Generator or Pulse Generator modes will overwrite any arbitrary waveform currently in memory Do not switch to these modes unless you wish to discard your arbitrary waveform 7 7 1 Using WAVELOAD EXE WAVELOAD EXE is a DOS program that will send a waveform file to the 625 through the serial port on your PC The program can add the necessary two character header before the waveform data WAVELOAD does not process or alter the data file in any way It simply sends a two character header described in the next section and then the contents of the specified file to the chosen serial port It is important that the baud rate setting of the 625 match the baud rate used by WAVELOAD EXE You may examine or change the baud rate of the 625 by pressing the Mode key and then the Offset key For more information changing the baud rate please refer to section 5 20 WAVELOAD EXE may be invoked from the DOS prompt as follows C gt WAVELOAD COMx y baud z filename ext where COMx specifies the serial port where x 1 2 3 4 for COM1 COM2 COM3 or COM4 y specifies the format of the a
121. section 2 0 18 5 6 Internal PM Mode Introduction The Internal PM mode generates a phase modulated signal of fixed amplitude An internally generated sinusoid is used as a modulating signal to vary the phase of a carrier sinusoid Internal PM Mode Parameters The Internal PM mode has the following front panel display O Int PM 1 000 Hz Pk dev 188 deg O 1 000 000 8 Hz 10 0 dBm Mhz Next Trigg 4 7 8 9 a ICursor Field DTMF Gen SSB Function Pulse KHz Mod QQ BC COEN gt DTMF Det Sweep FSK Burst re Hz Recall DO L1 2 13 nde gt ES n SYNC SIG Power Pwr meas AM FM M ut Out E L JL j olee O Arbitrary X Sinewave Oth TTL Cmos Zo 500 Figure 5 6 1 Internal PM mode display 1 Modulating Frequency In this field enter the frequency of the modulating sinusoid You may enter from 0 Hz to 10 000 Hz in 1 Hz steps 2 Peak Phase Deviation In this field specify the degree to which the modulating signal is allowed to change the carrier phase You may enter from 0 no change to 180 degrees in 1 degree steps This parameter is a peak value If the deviation value were 180 degrees for example then the output phase will advance to a maximum of 180 degrees and retard to a minimum of 180 degrees To enter a value type 1 to 3 numeric digits If you type 3 digits the value is automatically entered If you only type 1 or 2 digits you can press the MHz key or
122. ss Mode 9 Pulse Gen Pos Only N Duty Cucle 50 Cont Rep Freg 2 000 000 0 MHz 1 000 mV Mh Next Trigger DAA E i DTMF Gen SSB Function Pulse EN KHz Mod e DO 0500 OC 8 ove DIMF Det Sweep FSK Burst Ms Hz Recall Romote S 00 6 Cie Oe mus Power Pwr meas AM FM om 00 Out i C J LO L Joea O Arbitrar y XK o Sinewave Other TTL Cmos Zo 50Q 1 Positive Only This field when set to Y does not let the output signal go below OV This feature is handy when driving circuitry that cannot accept negative voltages This feature eliminates having to readjust the offset voltage to obtain a positive only signal every time the output level is changed When this field is set to Y the output level is halved so that the output signal swings from OV to Y the specified level into a 50 ohm load or OV to the specified level into an open circuit NOTE If you are using the Pulse Mode to drive digital logic you should use the SYNC Out connector on the front panel This signal has the same shape as the SIG Out signal but comes from a TTL CMOS driver 2 Duty Cycle In this field enter the duty cycle for the pulse waveform from 0 always low to 100 always high in 1 steps The duty cycle is the percentage of the waveform period that the output is high A waveform with a 10 duty cycle for example means that the output is high for 10 of the time and low for the remaining 90 of
123. steps This parameter is a peak value If the deviation were 1 KHz and the carrier frequency were 1 MHz for example then the output frequency will swing between a maximum of 1 MHz 1 KHz and a minimum of 1 MHz 1 KHz for an input signal level of 1 Vp p Note If values for the deviation and carrier frequencies are entered such that the output frequency exceeds the 0 to 20 0 MHz range distortion of the output waveform may result 2 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps Note If values for the deviation and carrier frequencies are entered such that the output frequency exceeds the 0 to 20 0 MHz range distortion of the output waveform may result 3 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to
124. t T for Integer format B for binary format 2 The waveform data values 3 An optional X or x character at the end of the data The X character denotes the end of data If the X character is missing the 625 will assume all data has been sent after 1 second timeout Whitespace spaces carriage returns tabs etc is allowed before or after the W character Whitespace may come after the format character except for Binary format For more information on data formats please refer to section 9 0 EXAMPLE Sending the following characters downloads a four point waveform in floating point format Ww F 1234 6874 2 345e 1 1 0 The serial port on the 625 defaults to the following parameters 1 start bit 8 data bits 1 stop bit no parity It is important that the sending program s baud rate match that of the 625 To inspect or change the 625 s baud rate press the Mode key and then the Offset key For more information changing the baud rate please refer to section 5 20 You do not need to tell the 625 how many points are in the waveform or which point is the last If the 625 does not receive any characters over the serial port for a 1 second time out then the 625 assumes that all arbitrary waveform points have been received If the 625 is in Arbitrary Waveform mode the new waveform will be generated immediately after the time out The second time out can be avoided by placing an ASCII X characte
125. t is reached If you select a Triggered mode then the waveform generation is halted after the last point is reached and the waveform is not restarted again until another trigger occurs The trigger can come from three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trig In connector 3 Sending an ASCII T to the RS232 port The 625 will simultaneously accept a trigger from all of the above sources To set Continuous mode press 1 To set Triggered mode press 0 Pressing any arrow key or rotating the wheel will toggle the run mode between Continuous and Triggered 2 Clock Frequency In this field enter the Arbitrary Waveform clock frequency This is the frequency at which your waveform values are sent to the Digital to Analog converter DAC You may enter from 0 Hz DC to 40 0000000 MHz in 1 Hz steps If a value of 0 Hz is entered the arbitrary waveform clock is halted 3 Level In this field enter the output level from 2 mVp p to 5 Vp p in 1 mV steps This level is the peak to peak voltage swing of the waveform across a 50 ohm load Into an open circuit the voltage swing will be twice the specified peak to peak value Offset You can enter a DC offset voltage for the output waveform by pressing the Offset key For more information on output offsets refer to the 625 Users Manual section 4 4 55 7 5 Function Generator Mode To enter the Function Generator mode press Mode 8 Function
126. ted 0 to 9 x A B C D Duration 1 mS to 10 000 Sec 1 mS steps Delay 0 mS to 10 000 Sec 1 mS steps Dual Tone Generation Mode Tone 1 Tone 2 Frequency DC to 10 000 KHz 1 Hz steps Phase offset 0 deg to 359 deg 1 deg steps Output On time 1 mS to 10 000 Sec 1 mS steps Output Off time 0 mS to 10 000 Sec 1 mS steps Function Generator Mode Waveforms Pos Neg Ramp Triangle Exponentials Noise Sine Repetition rate O Hz to 2 MHz in 1 Hz steps Run mode Continuous or Triggered 74 Sync Output Amplitude OV to 5V Fall Time 3 nS Rise Time 8 nS 10 to 90 Output current 24 mA Ext Trigger Gating FSK BPSK input Input impedance 80 KQ Max input level 10V Max gating freq 3 MHz General Power 100 240VAC 47 63 Hz 30W 3 prong IEC conn Display 2 line by 40 character LCD backlit Weight Approx 3 5 Ibs Dimensions 5 1 x 9 3 x 10 2 H x W x L Operating Temperature 0 to 40 deg C ambient Options e High Stability Timebase 5 ppm e DC Operation Binary Phase Shift Keying BPSK Mode Int modulation freq 0 Hz to 130 KHz 1 Hz steps Ext modulation freq 0 Hz to 10 KHz Amplitude Modulation AM Mode Int modulation freq 0 Hz to 10 KHz 1 Hz steps Ext modulation freq DC to 35 KHz Percentage modulation 0 to 100 1 steps Single Sideband SSB Mode Int modulation freq 0 Hz to 1 0 MHz 1 Hz steps Ext modulation freq DC to 8500 Hz Upper or Lower Sideband selectable Frequency Shift Ke
127. the KHz key or the Hz key all are equivalent to enter the degree value Note FM modulation is equivalent to PM for small frequency deviation values If you need a larger phase deviation than 180 degrees go to FM mode and specify an appropriate peak frequency deviation value 3 Carrier Frequency In this field enter the frequency of the carrier You may enter from 0 Hz DC to 20 0000000 MHz in 1 Hz steps 4 Level In this field enter the output level either from 2 mVp p to 5 Vp p in 1 mV steps or from 50 0 dBm to 18 0 dBm in 1 dBm steps NOTE The level specified is a 50 ohm LOADED level This is the level of the signal which will appear across a 50 ohm load connected to the SIG Out connector Into an open circuit the output swing will be twice the value entered Offset You can enter an offset voltage for the output waveform For more information on output offsets refer to section 4 4 Ext Gating Input rear panel connector This TTL compatible input can be used to gate the output signal on or off A logic high voltage turns off the output For further information on the Ext Gating Input refer to section 2 0 19 5 7 External PM Mode Introduction The External PM mode generates a phase modulated signal of fixed amplitude An externally supplied signal on the Ext Mod In connector is used to vary the phase of a carrier sinusoid External PM Mode Parameters The External PM mode has the following front panel display
128. the type of data you are sending to the 625 Please select a file type F Floating Point T Time amp Value Floating Point CSV PRN D Digital H Hexadecimal I Integer B Binary N Do not send a header Enter selection F T H I B N gt Enter F to indicate a floating point file Next you will be asked for the filename Enter filename ESC to exit gt Enter A ARB EXAMPLES SINE FLT and hit the ENTER key Note A quicker way to do the above is to enter all parameters on the command line For example if com port is 2 WAVELOAD COM2 F arb examples sine flt For further details see the chapter on using WAVELOAD EXE in the Users Manual 4 Press the blue MODE key once then the key and 1 to switch to Arbitrary Waveform mode The 625 will then generate the waveform at the selected clock rate and output level If you wish to change these parameters use the Next Cursor Field key to move the cursor to the desired field so that you may modify the value or type in a new value BNC Instruction Manual Model 625 625A Arbitrary Waveform Generator Berkeley Nucleonics Corporation 2955 Kerner Blvd Suite D San Rafael CA 94901 USA Ph 415 453 9955 Fx 415 453 9956 www berkeleynucleonics com 07 01 02 Berkeley Nucleonics Corp Model 625 Users Manual c BNC Corp ALL RIGHTS RESERVED PRODUCT AND DOCUMENTATION NOTICE BNC reserves the right to change this product and its documentation without prior notice Information furnish
129. the waveform period 3 Continuous Triggered mode In this field select whether the waveform is generated continuously or on a single event basis If you select Continuous mode then the waveform is immediately restarted once the end of the waveform is reached If you select a Triggered mode then the waveform is halted after the last point is reached and the waveform is not restarted again until another trigger occurs The trigger may come simultaneously from three sources 1 Pressing the Trigger key 2 Applying a low to high transition on the Ext Trig In connector 3 Sending an ASCII T to the RS232 port To set Continuous mode press 1 To set Triggered mode press 0 Pressing arrow keys or rotating the wheel will toggle the mode 4 Repetition Frequency In this field enter the frequency at which the function will be repeated You may enter from 0 Hz DC to 2 000000 MHz in 1 Hz steps If a value of 0 Hz is entered the function waveform clock is halted A high going synchronization pulse is given on the SYNC Out connector front panel at the start of the waveform In Triggered mode the waveform is generated once per trigger event The duration of each waveform will be 1 Repetition Freq Tip Very low rep rate frequencies lt lt 1 Hz can be generated by setting the Repetition Frequency to 1 Hz This fills the waveform memory with 16 000 points of the desired function Then goto Arbitrary Waveform Mode and enter the Clock Frequency
130. thout affecting the current setting press any key other a number or an arrow Disabling the serial port causes the 625 to ignore all incoming characters from the serial port Disabling the RS232 port does not affect the output of information i e the 625 will still output characters to the RS232 port Note The baud rate is not permanently changed unless the instrument setup is saved using the RECALL STORE key On power up the instrument setup is recalled from location 0 You may therefore change the power up baud rate of the instrument by selecting a baud rate and then saving the instrument setup to location 0 This menu does not change any other RS232 parameters The port is always set to 1 start bit 8 data bits 1 stop bit and no parity For information on remote control operation of the 625 refer to chapter 6 0 Remote Operation 34 5 21 Other Mode This mode displays a menu of extended modes that are available on the 625 It is used to present additional operating modes that are not printed on the front keypad The Other Mode menu is accessed by pressing the blue Mode key once and then the Clear key The user is then presented with the following menu on the LCD display Select Mode 1 BPSK lt gt toscroll 2 Dualtone Y ou can scroll through the list of available selections using the arrow keys The Y or gt key scrolls the display to higher selection numbers and the 8 or key scrolls the menu to lower selection nu
131. value precedes each Point Value Since the 625 does not need the Time or Point Number specifying this format causes the 625 to skip every other number it encounters starting with the first floating point number All rules for this format are identical to those for Floating Point Format except that the Time or Point Number value need not be between 1 0 and 1 0 in value since the 625 discards these values during the download This format is useful since many graphical waveform design programs allow you to save your work as a disk file in this format The filenames often have a CSV comma separated values or PRN Printer tab separated values extension Both file types may be downloaded directly without modification by using the T format switch with WAVELOAD EXE or adding a WT header when downloading with your own program Example A ten point waveform with SYNC Out set high on point 2 0 000000 p 1 031411E 1 2 062791 3 094108 4 1 0 5 156434 6 187381le 2 7 218143 8 248690 9 278991e 03 10 309017 Example 2 The same ten point waveform with the values separated by tabs Note Any whitespace character s defined in the rules for Floating Point format may be used to separate the numbers 000000 031411E 1 062791 094108 1 0 156434 187381le 2 218143 248690 278991e 03 0 309017x FPWoOMATA TBWNHED O The x character at the end denotes the end of the data a
132. ve dBm value press the key while entering the value Finally press the dBm key to enter the value as dBm or the Vp p or mVp p keys to enter the new value as a peak to peak voltage Note The level you re entering here is considered a LOADED level i e the level that will appear across a 50 ohm load connected to the output To modify an existing level value use the Y and keys to position the cursor within a field Place the cursor over the digit you wish to change and press the or Y key to increment or decrement the digit Alternatively you can turn the rotary knob clockwise or counterclockwise to adjust the digit s value Changing Operating Modes To select another operating mode press the blue Mode key once When pressed the LCD display is cleared and the question Mode is displayed The Mode key acts as a shift type key in that the meaning of each button on the front panel changes to that described by the blue wording beneath it To enter the SWEEP mode for example first press the Mode key and then press the number 4 key You can then use the Next Cursor Field key to move the cursor to the parameter you wish to change Each numeric value can be entered or modified in the same manner described above The user s manual contains a separate chapter for each mode which describes in detail all parameters on the LCD display Arbitrary Waveform Mode Quick Start Guide This guide will show you how to download and generate SINE FLT a
133. wave e DTMF Generation e Internal External AM e DTMF Detection e Internal External FM e Voltage amp Power Measurement e Internal External PM e Burst Continuous or Int Ext trig e Internal External SSB e Sweep e Internal External BPSK Linear Log Continuous Triggered Up Down e Internal External FSK e Dualtone Generation e Data Modulation e Voltage Controlled Oscillator VCO Options contact factory for availability e High stability timebase e DC Operation 2 0 Hooking up the 625 This section discusses how to properly connect the 625 to your equipment The following diagrams identify the connectors and show typical hookups Store Recall Remote SYNC SIG Out Out TTL Cmos Zo 50Q Figure 2 0 1 Front Panel Connectors Each connector on the front and the back of the 625 is discussed here 1 SYNC Out connector This connector provides a digital signal which swings between OV and 5V providing a logic level output useful for driving digital circuitry This output is capable of driving TTL or CMOS loads Its output current capability is 24 mA In all sinewave and modulation modes except sweep this connector supplies a squarewave version of the signal on the SIG Out connector It has a fixed 50 duty cycle In the Sweep mode this connector provides a high going pulse at the beginning of each sweep In the Arbitrary Waveform Generator m
134. y to go to DTMF Detection mode Wait for the user to press a key before we switch to a new mode CALL Pause PRARS TOS Switch to DTMF Detection mod This example illustrates how to parse information from the 625 PRINT 1 MD Command the 625 to go to DTMF Detection mode GOSUB PromptWait Wait for 625 to finish this command GOSUB FlushBuffl Flush all received chars from 625 Let the user know what s going on CLS PRINT PRINT PRINT Now in DTMF Detection mode All DTMF detections will be printed PRINT When the 625 detects a DIMF digit it will print the following text to the terminal port CR LF DTMF 7 DIMF Loop GOSUB GetResponsel Wait for and get response from 625 to a The 625 prints a semicolon character whenever it is reporting data The data follows immediately after the semicolon IF INSTR aS THEN a INSTR aS 1 Get the data that follows the character aS MID a a 2 Strip off everything else PRINT Detected DTMF digit is a END IF Allow the user to exit the program by pressing a key IF INKEYS lt gt THEN SYSTEM Exit on first terminal keypress GOTO DTMF Loop Otherwise keep looking for more DTMF detections 78 SUBROUTINES These subroutines are also used by other example programs Get ASCII response from 625 Wait for an incoming char then collect incoming stuff until we
135. ying FSK Mode Int modulation freq 0 Hz to 130 KHz 1 Hz steps Ext modulation freq 0 Hz to 3 MHz Mark Space freqs 0 Hz to 20 0 MHz 1 Hz steps Data Modulation Mode Baud Rate 0 Hz to 130 KHz 1 Hz steps Message Length 1 to 960 bits Mark Space freqs 0 Hz to 20 0 MHz 1 Hz steps Power and Voltage Measurement Mode Input signal level 5V max 10V p p Input signal bandwidth DC to 50 KHz Power calc impedance Variable from 1 to 999 ohms Dual Tone Multi Frequency DTMF Detect Mode DTMF digits detected 0 to 9 x A B C D Detection range 10 Vp p max 20 mVp p min Detection time 100 mS Arbitrary Waveform Generation Mode Vertical resolution 12 bits Sample update rate DC 40 MHz in 1 Hz steps Sample buffer depth 32 768 points Run mode Continuous or Triggered Pulse Generator Mode Frequency 0 Hz to 2 MHz in 1 Hz steps Duty cycle 0 to 100 in 1 steps Tr Tf 28 nS 10 to 90 1Vp p Variable in amplitude amp offset TTL CMOS output also 10 0 The Floppy Diskette Description The floppy diskette which accompanies this manual contains a number of useful utilities and example programs Below is a list of the directories on this disk and a description of the files within each Within each directory is a file called README which explains the purpose of the files in that directory The files and their purpose are listed here as a convenient reference CALIBRAT SG100CAL EXE A utility to calibrate the 625 SG1

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