Home

Digital Storage Oscilloscopes Operators Manual Gould 400 Series

1. Figure 3 Menu Overview Menus 3 1 3 2 3 1 Additional Buttons 3 1 1 The Numeric Buttons The buttons 1 to 7 36 are used in conjunction with the menu system to provide a large number of extra functions not otherwise available directly from the front panel Pressing these buttons when the menus are displayed operates the menu functions described in Sections 3 2 to 3 12 Buttons 0 8 and 9 have extra functions described below Figure 3 1 The Numeric Buttons 3 1 2 0 Menu Traces Menu Traces 35 Toggles the display between the traces and the last used menu 3 1 3 9 Control Control 7 The current display whatever it may be is replaced with the Control Master Menu 3 1 4 8 Post Store Post Store 6 Brings the Post Storage Master Menu onto the display 400 Series Operators Manual 3 2 Control Master Menu Each entry on the Control Master Menu 15 also menu cov ering one set of functions The text is lined up with the numeric buttons 1 7 on the side of the display To obtain any secondary menu simply press the relevant button lt lt CONTROL MASTER MENU gt gt am Mast LE DISPLAY AND TRIGGER 2 CA DISPLAY INTENSITY 3 LJ REFERENCE TRACE 4 Co RS423 INTERFACE 5 E PECIAL FUNCTIONS 6 E73 7 Co Post Store 8 5 Control Figure 3 2 Control Master Menu
2. HORIZONTAL Position 4 4L D 1 1 i ee Oed Mode SiShot Run cc HONIZONTAL TIME DIV das ae 72 CH1 IX CH2 EXT TRIG 5 1v 1400 ph 24009 Figure 1 2 The Pressure Sensitive Buttons Getting Started 1 1 7 1 4 1 CAUTION The negative DC terminal is connected to the safety ground terminal and the instrument case Care should be taken to avoid ground loops when for example the instrument is used in a vehicle and powered by that vehicle s supply 1 1 7 Fuse Requirements The fuse arrangement shown in table 1 1 7 must be followed and additionally in the UK a 3A fuse 5A if the battery unit is fitted should be fitted in the line supply plug Supply Slow Blow Gould Suggested types Voltage Fuse Rating ULICSA DSO 230V 0 5A 0 6A 457452 BeswickrrDC488 Littlefuse 239 Schurter FSP 115V 1 1 2A 457454 BeswickrrDC488 Littlefuse 239 Schurter FSP 12VDC 5A 457979 HRC type Beswick S505 Wickman 19181 BATTERY UNIT 230V 1 1 2A 457454 BeswickrrDC488 Littlefuse 239 Schurter FSP 115V 2A 2 5A 457455 BeswickrrDC488 Littlefuse 239 Schurter FSP Table 1 1 7 Fuse ratings Part No Manufacturer Type No Note For different DC voltages the DC fuse rating multiplied by the voltage used should equal60W e g at 30V a 2A fuse is required For addition
3. Levelled signal generator Tektronix SG503 or similar 50 Ohm coaxial cable 50 Ohm terminator Connect the signal generator to a channel input through the coax cable and the terminator which should be at the 400 end of the cable l Select 100m Y per division on the input channel and 500ns per division on the timebase 2 Set the signal generator to 20MHz and adjust its amplitude to give one and one half divisions on the screen It should be possible to adjust the trigger level to give a stable triggered trace 4 5 Timebase Calibration Equipment required Time calibrator Bradley oscilloscope calibrator type 192 or Tektronix TG501 or similar 50 Ohm coaxial cable 50 Ohm terminator Connect the calibrator to a channel input through the coax cable and the terminator which should be at the 400 end of the cable Checking 4 6 4 7 1 Select a suitable timebase range to view the signal and set the channel attenuator to give between two and five vertical divisions of signal 2 Select DC Coupling and Norm on the trigger con trols Adjust the trigger level to give a stable trace Change the timebase to 500ns per division Set the calibrator to produce markers every 500ns e um Select the cursors With the cursor and time datum on identical positions on any two markers the time difference should read in multiples of 500ns to within 1 Note Failure of this specification
4. Once this condition is detected the battery supply to the DSO is automatically switched off When the fault has been remedied the alarm condition can be cleared by turning the master power switch 3 7 off for at least 10 seconds and then on again The alarm lamp 3 8 will be illuminated constantly if the battery temperature trip operates see section 6 5 or if a severe fault blows the internal battery protection fuse Replacement of this fuse requires removal of the instrument covers and it should only be attempted by suitably qualified personnel See section 1 1 3 6 5 Extreme Temperature Operation and Storage The DSO may be powered from the battery unit at any ambient temperature up to 45 C However the internal battery temperature detector may inhibit full fast charge at temperatures above 35 C In this condition both the standby charge lamp 40 and the alarm lamp 3 8 will be on constantly Charging is interrupted until the battery temperature reduces naturally to below the trip temperature when the alarm lamp will be extinguished Standby charge will then be resumed At least 24 hours standby charge may then be required to regain full charge Although the battery unit may be stored at temperatures up to 50 C and operated at temperatures up to 45 C it is recommended that the period of such usage is limited Pro longed exposure to high temperatures will adversely affect the battery life The battery unit m
5. volt seconds or similar units lt lt TRACE ARITHMETIC MENU gt gt 5 3 Trace Arithmetic 2 REF Pressing button 6 on the Post Storage Master Menu selects the Trace Arithmetic Menu figure 5 0918 SUBTRACT MULTIPLY TR1 REF RESULT TO TR2 Wild Using buttons 1 2 and 3 the traces involved and the calculation required can be chosen with the selected option being highlighted When multiply is selected the scale line next to button 5 appears so that a scale factor can be applied to the calculation result to allow it to fit on the screen SCALE 0 5 x0 2 x0 1 The result of the arithmetic will be stored in the highlighted trace selected with button 4 EXECUTE Pressing button 7 Execute causes the calculation to happen Figure 5 3 Trace Arithmetic Menu Waveform Processing 5 4 5 4 2 5 4 Persistence Limits Testing Button 7 on the Post Storage Master Menu selects the Per sistence Limits Menu figure 5 4 lt lt PERSISTENCE LIMITS TESTING gt gt SET UPPER LIMIT SET LOWER LIMIT TEST LIMITS On Stop on fail DISPLAY LIMITS On PERSISTENCE Off Cycles PERSISTENCE TIME s 0 5 2 0 5 0 30 90 PERSISTENCE CYCLES 20 50 100 200 500 Figure 5 4 Persistence Limits Testing Menu 5 4 1 Limits The upper and lower limits to be tested against are set by displaying the desired limit trace on the screen and then pressing either button 1 or 2 as required When a limit has been s
6. 4 2 Bandwidth Equipment required Levelled signal generator Tektronix SG503 or similar 50 Ohm coaxial cable 50 Ohm terminator Connect the signal generator to a channel input through the coax cable and the terminator which should be at the 400 end of the cable l Select 5mY per division on the input channel and set the timebase to 50jLs per division 2 Set the amplitude of the signal generator to give six divisions at SOkHz or similar reference frequency 3 Change the timebase range to 500ns per division Performance Checking 4 1 4 5 4 Increase the frequency on the signal generator until the peak to peak amplitude reduces to 4 2 divisions The measured frequency should be greater than 20MHz 4 3 Trigger Sensitivity Equipment required Signal generator Tektronix SG503 or similar 50 Ohm coaxial cable 50 Ohm terminator Connect the signal generator to a channel input through the coax cable and the terminator which should be at the 400 end of the cable 1 Select 100mY per division on the input channel and set the timebase to 50jLs per division 2 Select Auto trigger 3 Set the signal generator to 50kHz or similar reference frequency and adjust the amplitude to give 0 3 of a division peak to peak 4 Select AC Coupling and Norm on the trigger con trols It should be possible to find a suitable trigger level to obtain a stable triggered picture 4 4 Trigger Bandwidth Equipment required
7. The options available on the Control Master Menu are as follows STATUS Displays information about the present setup of the instrument See section 3 3 DISPLAY AND TRIGGER Controls probe sensitivity averaging interpolation the glitch detect function and trigger delay See section 3 4 DISPLAY INTENSITY The the brightness of alphanumerics graticule cursor and traces can all be adjusted independently See section 3 5 REFERENCE TRACE Either one of the currently displayed traces can be copied to the reference trace See section 3 6 RS423 INTERFACE Setting the RS423 output protocol See section 3 7 SPECIAL FUNCTIONS Enables the user to disable the auto calibration calibrate either channel or force a full calibration See section 3 8 400 Series Operators Manual The Menus 3 3 3 3 Status Menu 3 3 4 Probe Set The probe gain settings are shown as 1 This menu allows the various horizontal vertical and trigger x10 or x100 These may be set using the Display and settings of the instrument to be viewed typical display 15 Trigger Menu See Section 3 4 shown in Figure 3 3 3 3 5 Timebase The sweep rate of the timebase is shown 5 ms LS or ns per division Menu Traces 3 3 6 Trigger This section of the display shows the selected lt lt STATUS MENU gt gt L3 trigger options The choices of source are CH1 CH2 Refresh 1 03 Ext and Line The available couplings are AC DC and Off high
8. Triggered the instrument has received or generated a valid trigger acquisition has begun S Stored acquisition is complete 2 3 Display Modes The following three display modes are directly selectable using the Mode button 31 Refreshed The instrument will imitate the style of a conventional realtime scope the display is plotted from left to right as it is acquired Roll This mode 15 like a chart recorder the display scrolls from right to left until a trace has been acquired The scrolling effect is most noticeable on the slower timebase ranges The rolling display is frozen by the trigger in S Shot mode and 15 unaffected by trigger in Run X V This mode allows the CH1 socket input to control the X horizontal component of the trace and the CH2 400 Series Operators Manual socket input to control the Y vertical component It provides an X Y display of the data captured by the time base and trigger systems The timebase should be set slow enough to capture the whole of the signal of interest This mode is not available with magnified traces Mag 2 4 Cursor Measurements The instrument allows you to take direct measurements from the screen display automatically using inbuilt datum lines and cursor losf STORAGE DATUM Figure 2 4 The Cursor and Datum Line Controls 2 4 1 Cursor and Datum Selection The cursor and datum lines are switched on or off using the Select Trace button 4 Select Trace
9. trace memories and the plotter Traces lt lt POST STORAGE MASTER MENU gt gt 0 o SAVE TRACE ea 1 73 RECALL MEMORY m PLOT OPTIONS E 3 CURSOR MEASUREMENTS 4 oo TRACE MANIPULATION 5 TRACE ARITHMETIC 6 I PERSISTENCE LIMITS TESTING T CJ Post Store BU Control Q 3 Figure 3 9 Post Storage Master Menu Lines 4 to 7 only appear on a 420 or 450 instrument and are the waveform processing functions Their operation is fully described in section 5 400 Series Operators Manual 3 10 Save Trace Menu This menu allows you to store up to three traces including the reference trace to the battery backed memories Menu 5 lt lt SAVE TRACE MENU gt gt A estos 1 CY Save Trace 2 2 Save Trace E J 4 5 SAVE TRACE 2 TO Memory 1 5 2 6 Memory3 7 I Post Store 8 CI Control Figure 3 10 Save Trace Menu Because these memories are battery backed the traces stored in them will not be lost even when the instrument is powered down SAVE TRACE Using the 1 2 or 3 keys selects either Trace 1 Trace 2 or the Reference Trace respectively to be saved Once the trace has been selected a fresh option will appear described below SAVE TRACE TO MEMORY Any of the three battery backed memories may be selected The Menus 3 10 3 11 3 11 Recall Memory Menu Traces previously saved using the Save Trace menu can
10. 20mV X MAG ON Y MAG x1 438 AFTS RESTORE 1 CH1 0 2V TB 0 5us LIMIT TEST PASS RISE FALL 10 90 123 4us Max 2 87V MIN 2 6V 12 0KHz 83 00us 48 2 DEL 12 80 5 Figure 5 1 Example of Calculations on Trace If all the cursor measurements are set to off the cursor data line on the display will show the message TRI CURSOR MEASUREMENTS OFF and if the data is invalid for the measurement selected the cursor line will display the message TRI INVALID DATA The trace number in both the above messages will change according to the selected trace 5 1 1 Voltage and Time The display shows the voltage between the voltage datum line and the point where the cursor line crosses the trace and the time between the time datum line and the cursor line Figure 5 1 1 Voltage and time Measurement Waveform Processing 5 1 2 5 1 4 5 1 2 Peak Peak The display will show the peak to peak voltage difference between the most positive and negative points of the trace between the cursor and the time datum 400 Series Operators Manual 5 1 4 Risetime falltime Position the cursor and the time datum at the 0 and 100 points of the waveform The software will calculate the rise or fall time between the low and high percentage points of the Trace measured between Time Datum and Cursor Figure 5 1 2 Peak to Peak Measurement 5 1 3 Max Min The display shows the voltages of the maximum and minimum points of the waveform b
11. 3 Live Parts The instrument should not be operated with covers removed The covers protect the user from live parts and 400 Series Operators Manual they should be removed only by suitably qualified personnel for maintenance and repair purposes WARNING Removing the covers may expose voltages in excess of 8000V at the side of the display tube these may be present for up to one minute after the instrument has been disconnected from the power source 1 1 4 Ventilation and Dust The instrument relies on forced air cooling via a fan and ventilation slots Adequate ventilation can usually be achieved by leaving a 75mm 3 gap around the instrument The instrument should not be operated in dusty environments If the CRT filter requires cleaning it can be easily removed by pressing in its right hand edge as shown by the moulded arrow 1 1 5 Operating Temperatures The instrument is designed to be operated in an environment having an ambient temperature of between 0 and 50 degrees 0 to 45 degrees if the battery unit 1s fitted and to operate with full accuracy between 15 and 35 degrees C Note Direct sunlight radiators and other heat sources should be taken into account when assessing the ambient temperature The instrument may occasionally be subjected to temperatures between and 10 C without degradation of its safety 1 1 6 Power and Frequency Requirements The instrument uses less than 85V A 200V A if battery un
12. 5 Paper Loading 2 5 6 Internal Plotting When a plot is initiated the Hold lamp lights and the message PLOTTING PRESS PLOT TO ABORT appears on the screen After about 9 seconds the hold lamp goes out indicating that the data has been transferred to the plot buffer and that the instrument can be used again The plotting message will remain on the screen until the plot 15 complete when it will disappear In Auto Plot Mode the instrument is re armed after the plot data has been transferred to the plot buffer but the front panel controls will remain in active during plots 400 Series Operators Manual If the plot button is pressed while the plot is in progress the plot will be aborted Any changes to the instrument status during a plot will have no effect on the plot as the data has already been transferred and stored in the plot buffer 2 5 7 External plots A plot of the display can be sent to an external plotter by pressing the plot button Q The parameters for the plotter and the plot format can be set as described in section 3 7 and 3 12 The display is held while a plot is in progress Plots can be aborted by a second press of the plot button If the plot is aborted the pen will be left in a random position and the external plotter may need to be reset to restore the pen to its start position 2 5 8 Plot positioning and scaling The output plot from the 400 has the relative positions shown in figure 2 5 8
13. Datum Line Controls The Cursor and Datum Lines Paper Loading Relative Plot Positions Plot Dimensions Menu Overview Numeric Buttons Control Master Menu A Status Menu A Display and Trigger Menu Display Intensity Menu Reference Trace Menu An RS423 Interface Menu 400to Gould 6120 or HP7475 Connections 400 to IBM PC XT Connections 400 to IBM PC AT Connections Special Functions Menu Post Storage Master Menu Save Trace Menu Recall Trace Menu Plot Menu Cursor Measurements Menu Example of Calculations on trace Voltage and Time Measurement Peak to Peak Measurement Max Min Measurement Risetime Measurement Overshoot Measurement Pulse Width Measurement Freq Period and Duty Cycle Measurement Area Measurement Trace Manipulation Menu Persistence Limits Testing Menu Battery Unit Interconnections Battery Unit Front Panel Indicators 400 Series Dimensions DC Power Connections Rear View RS423 Connections F Tul a ee 400 Operators Manual Introduction The Gould 400 series instruments are Digital Storage Oscilloscopes DSOs They include all the features expected of advanced modern oscilloscopes designed for the professional engineer whilst retaining the user friendliness essential for those learning to use such instruments for the first time The 400 range consists of three basic models the 400 the 420 and the 450 AII versions can be fitted with a battery unit which provides the instrument with a fully autom
14. The aim of this section 15 to allow the user of a 400 oscillos cope to verify the major analogue performance parameters Should any of these fail to be within specification then it is recommended that the instrument be re calibrated A skilled technician with the aid of the service manual should be able to perform this task alternatively return the instrument to your Gould distributor 4 1 Risetime Equipment required Fast edge pulse generator lt Ins Bradley oscilloscope calibrator type 192 or Tektronix PGS06 or similar 50 Ohm precision coaxial cable 50 Ohm precision terminator Connect the pulse generator to a channel input through the coax cable and the terminator which should be at the 400 end of the cable l Select 100mY per division on the input channel and set the timebase to Suss per division 2 Set the generator to give 600mY peak to peak at a repetition rate of 1 MHz and adjust the trigger level to give a stable trace 3 Select the cursor and change the time base to 500ns per division 4 Apply x10 trace magnification using the Mag button to give 50ns per division and adjust the horizontal Position buttons to centre the fast edge 5 Position the cursor and datum lines on the edge such that the cursor is 60m Y below the high level and the datum lines cross 60m Y above the low level The rise time can now be read from the cursor line on the bottom row of text This figure should not be greater than 18ns
15. an incoming AC supply In order for them to start working they first have to detect the loss of the AC supply which can take a few seconds Any applications which require continuous operation of a DSO regardless of AC supply fluctuations or drop outs as well as those requiring a remote power source will benefit from the versatility of the 400 series DC power feature Some examples of these applications are uninterruptible power supply development and troubleshooting and troubleshooting of supply interference caused by large electric maCH Ines The DC operation power dissipation of the 400 15 about 60W and of the 420 and 450 about 62W 67W when printing This dissipation is a constant power load to the source This means that less current is drawn at higher voltages and conversely more current at lower voltages The user should ensure that there is sufficient source voltage to overcome cable and connector voltage losses that may occur because of the relatively high current involved See table A3 1 Figure A3 2 below shows the 400 s internal arrangement of the power connections It can be seen that current will be drawn from the AC supply as long as the external DC input voltage is lower than the AC input voltage minus the two diode voltage drops in the bridge rectifier This simple diode O Ring of the two power sources means that switCH 1ng from one source to another is very quick there is no interruption in the operation of the instrum
16. and Alphanumerics VERTICAL SYSTEM Two identical channels and CH2 Inputs via BNC connectors Sensitivity 2mV div to 5V div in 1 2 5 sequence Accuracy 2 5 of reading 1 digitising level 1 30 of a division Variable Sensitivity gt 2 5 1 range allowing continuous adjustment of sensitivity between ranges Input Impedance 28 Input Coupling DC GND AC Bandwidth 400and420 DC 0 20MHz 3dB AC 4Hz 20MHz 3dB DC 0 450 50MHz 3dB AC 4Hz SO0MHz 3dB Input protection 400V DC or peak AC at 10kHz or less Expansion Post storage x 0 062 to x 4 00 HORIZONTAL SYSTEM Timebase Sweep rate 400 and 420 27 ranges in 1 2 5 sequence 450 28 ranges in 1 2 5 sequence Transient capture 500ns div to 50s div Repetitive sampling 400 and 420 200 and 100ns div 450 200 100 and 50ns div Sample rate accuracy 0 01 of sample time Expansion x 10 with linear dot interpolation TRIGGER DELAY Trigger delay range 20ns to 5000s Trigger delay accuracy 0 01 1 ns Pre trigger 0 to 100 of sweep in 0 4 steps Resolution 2 of time div 20ns min TRIGGER SYSTEM Variable level control with Auto Normal facility resolution of less than 0 1 div 400 Series Operators Manual Auto Normal Mode Auto the timebase free runs when insufficient signal 20Hz 20M Hz 15 present or when the selected level is outside the range of the input signal Source CH1 CH2 External
17. be recalled using this menu lt lt RECALL MEMORY MENU gt gt 0 293 Recall Memory 1 1 1 LJ Recall Memory 2 2I Recall Memory 3 4 LJ ECALL MEMORY 3 TO ES Trace 1 5 Ca Trace2 6 CJ RefTrace 7 PES Post Store 8 Ca Control 9 C Figure 3 11 Hecall Memory Menu RECALL MEMORY One of the three memories may be recalled by pressing the button 1 2 or 3 Having chosen a memory you will be asked into which display trace you would like to place it RECALL MEMORY TO TRACE Pressing button 5 6 or 7 will cause the trace data from the previously selected memory to be displayed on trace 1 trace 2 or the reference trace NOTE Unless the selected trace 1s held or acquisition is not armed the selected memory data could be over written soon after it is displayed Menus 3 12 3 12 Plot menu This menu allows the user to set the format of the plot sent to the internal colour plotter or to the external plotter via the RS423 interface Refer to Section 3 7 for RS423 connections Menu t P Traces lt lt PLOT MENU gt gt o IPLOT MODE Single Auto L3 PLOT WITH GRATICULE Off On 2 LINE TYPE Solid Broken l3 r3 i Off PLOT WITH CURSORS O n 4 C3 IPLorourPUT s423 5 i Internal 5 c3 ADVANCE PAPER 6 Co 7 Co Post Store 8 Control 9E Figure 3 12 Plot Menu PLOT MODE This can be set to either Single or Auto with successive presses of th
18. can be removed by selecting AC coupling Any vertical shift applied to the trace is not inverted The trigger point remains at the same point on the waveform regardless of inversion 1 5 1 TIME DIVISION TIME DIV 33 These buttons control the sweep rate of the trace The timebase can be varied from 100ns div to 50s div in a I 2 5 sequence of values The button marked ns decreases the time div the button marked sec increases the time div With a timebase of say 200 Ls each horizontal screen division represents 200 Ls worth of signal The timebase is shown near the top of the display e g TB 200 Ls Assuming 2kHz signal is applied as mentioned earlier when the timebase is set to 500ms div an interesting phenomenon may appear an alias Getting Started 1 5 2 1 6 3 1 5 2 Aliases An alias is a false image The instrument is a digital oscilloscope and so takes frequent samples of the input signal in order to update the trace Thus if the signal frequency is higher than the sample frequency one sample will be taken from a particular point on the waveform and the next sample may be taken from a point slightly further along on a subsequent cycle It will then display the wave as being much slower than it really is See Figure 1 5 2 This effect is only likely to occur if there are more than 100 cycles of waveform across the screen signal illusory image Figure 1 5 2 Alias Generation There is a M
19. chassis POWER INPUT FUSE 12 33V 5A 12V 2 33 RS 423 OUTPUT ieu 400 Series Operators Manual Appendix 4 Front amp Back Pictures 00 CS 09 QU dic M Post Store 8 Q F C ntrol 0000900201 OO Fig 4 Front Panel Control Service Facilities Service Facilities Gould and its distributors and agents maintain comprehensive after sales facilities and whether or not it is still under guarantee the instrument should be returned to the local Gould service centre or distributor through whom it was supplied for servicing if this 18 necessary The type and serial number of the instrument should always be quoted together with full details of any fault and service required PRINCIPAL GOULD SERVICE OFFICES AUSTRIA Gould Electronics GmbH Niederlassung Wien Mauerbachstrasse 24 A 1140 Wien Telephone 222 972506 Telex 01 31380 Fax 222 97250638 FRANCE Gould Electronique 57 Rue Saint Sauveur Ballainvilliers 91160 Longjumeau Telephone 6 934 1067 Telex 600824 GOULD Fax 6 934 2073 Adresse postale B P 115 91162 Longjumeau Cedex GERMANY Gould Instruments Waldstrasse 66 6057 Dietzenbach Telephone 06074 4908 0 Fax 06074 4908 48 WL490 400 Operators Manual Equipment returned for servicing must be adequately packed preferably in the box in which the product was supplied and shipped with transportation charges prepaid We acc
20. frequency reject These are discussed in Section CH1 CH2 2L 2 2 2V 1 x1 3 C TIMEBASE 0 2ms X MAG x1 4 LJ TRIGGER e va oe 5 C The trigger level is shown in terms of the number of seni oi ODIV 6 3 screen divisions above the bottom of the graticule The SLOPE ve trigger slope is shown as either ve rising edge or ve DELAY 11 120ns 7 falling edge Control E Following this is the trigger delay setting given in s ms ope 418 or ns as appropriate For pre trigger operation the figure is given as a percentage 0 places the trigger Figure 3 3 A Status Menu point at the left hand edge of the screen and 100 on the right hand edge 3 3 1 Mode There are three possible display modes Refresh Roll and X Y They are described in Section 2 3 3 2 Max Min The glitch detector 15 selected using the Display and Trigger Menu See Section 3 4 3 3 3 V Div The input sensitivity of the channels 15 shown in volts per division The range is 2mV to 5V per division If Add mode is selected a sign is shown between the channels Along with the input sensitivity of the channels other information is also shown The symbols used are as follows Trace inverted gt Uncalibrated AC coupled Calibrated Trace off top of display gt Trace off bottom of display Menus 3 4 400 Series Operators Manual 3 4 Display and Trigger Menu This menu controls probe ratios detection inte
21. or Line Coupling DC AC high frequency reject filter Slope ve or ve Sensitivity 400 and 420 Internal DC Coupled lt 0 3 div DC to 2M Hz lt 1 5 div DC to 20MHz AC Coupled lt 0 3 div 10Hz to 2 MHz lt 1 5 div 4Hz to 20MHz External DC Coupled lt 150mV DC to 2MHz 600mV DC to 20MHz AC Coupled 150mV 10Hz to 2MHz 600m V 4Hz to 20MHz Sensitivity 450 Internal DC Coupled 0 3 div DC to 2MHz lt 1 5 div DC to 50MHz AC Coupled 0 3 div 10Hz to 2MHz lt 1 5 div 4Hz to 50M Hz External DC Coupled 150m V DC to 2MHz 600mV DC to 50MHz AC Coupled 150mV 10Hz to 2MHz 600mV to 50M Hz Range Internal 10 divisions External 3V External input impedance 100K 1 10pF External input protection 250V DC or peak AC Trigger jitter 50s Div to 0 5fLs Div 2 of time Div unexpanded 2ns 0 2fLS Div and 0 1fLs Div 2ns DISPLAY MODES Refreshed Stored data and display updated by triggered sweep Roll Stored data and display updated continuously for timebases 50ms div to 50sec div Trigger stops the updating process Refresh and roll operate as repetitive single shot for timebase ranges faster than 50ms div Dot join Dots are joined by vertical raster lines Linear dot interpolation is provided when the trace is X expanded X Y X Y display is 8 X 8 divisions Stored data and display are updated by triggered sweep There is no dot joining X 10 expansion or cursor in this mode 15
22. rej AC DC 18 Trace Hold on Release Trace Hold 25 Timebase on very slow acquisition Adjust TIME DIV 33 1 8 4 Problem Trace is unstable even when triggered Alias Check for alias using Max Min glitch detection and select a faster timebase range Noisy input Select hf rej trigger coupling 18 Adjust trigger Level 22 Trigger on Auto With low frequency inputs below 20 2 Auto trigger will initiate triggers overriding the input triggers Select Norm trigger 20 1 8 5 Problem Trace has a very flat top or bottom Trace captured when off screen vertically and Pos n shift has been used Use less sensitive V DIV range when acquiring trace 11 Re position trace prior to capture Advanced Features 2 1 2 1 5 2 Advanced Features 2 1 Trigger Control Trigger facilities discussed here are controllable directly from the front panel For the more advanced menu controlled facilities see Section 3 4 The power down trigger setting will be retained on future power up hf rej AC OC CHI CH2 Ext Line Figure 2 1 Trigger Controls 2 1 1 Selecting Source and Coupling The lowest button in the TRIGGER section of the front panel selects the source of the trigger CH1 CH2 Ext line 17 Steps through the possible sources of trigger signals When Ext is selected the source is the EXT TRIG socket 16 in the lower right corner of the front panel Selecting line is meaningful only if the in
23. vollages present XXXXZXERE For use by qualified laboray Pour par le parse Swich off power before connecting or disconnecting interfaces Battery Unit Operation 6 1 The battery unit is electrically connected to the DSO by two rear panel cables one for the AC supply and one for the DC supply CAUTION Before use ensure that the connections between the battery unit and the DSO are correct see figure 6 0 6 1 AC Supply Operation To operate either the DSO or the battery unit the master on off switch 3 7 on the front of the battery unit must be turned on If the instrument has been unused for a period of a month or more at 20 C or for a week or more at 50 C individual cells within the batteries may have lost different amounts of charge 24 hours operation on charge is required prior to discharge With an AC supply applied to the battery unit and the master power switch 3 7 turned on the batteries are on charge See section 6 3 When the DSO power is also switched on the DSO operates from the AC supply Normal operation of the oscilloscope 15 possible and the batteries remain on charge eu Bow Fuse UL CSA 45 440Hz 5 CAUTION Negative DC terminal To Independent Ground See Section 1 1 2 Master AC Input and Fuse Ut Velaoe Nom Range 44 1 i IEC UL CSA 45 440Hz 120W 180VA CAUTION Set both Voltage Selectors F
24. which may be between 10Hz and 20MHz AC DC Gnd 14 Controls the type of coupling between the instrument and the input signal AC 15 used to remove DC components from signals of between 2 and 20MHz DC couples the input signal directly to the instrument so all frequency components of the signal up to 20MHz will be displayed Gnd internally disconnects the inputs from the instrument reference signal is displayed instead Add 10 Displays the sum or difference if one channel 1s inverted of the channels The original traces disappear and the resultant trace is displayed as a new Channel 2 trace Arm d 29 Illuminates after S Shot is pressed it will stay lit until either valid trigger has been received or the Run button has been pressed AUTO SETUP 24 Will attempt to arrange the display so that two to five complete cycles appear with the amplitude set so that the height of the trace is between two and five screen divisions Also it selects Auto trigger to ensure that the screen is frequently updated and a trace will be visible If the frequency of the input signal is less than 20Hz this function may not operate correctly Auto Norm 20 Selects the trigger mode Norm means that valid triggers must be received to initiate captures Auto triggering is the same as Norm except that if no valid trigger has been received for some time an artificial trigger will be generated the instrument will generate its own trigger
25. 1 1 Numeric Buttons 1 5 Horizontal Adjustments 3 1 2 Menu Traces 1 5 1 TIME DIVISION 3 1 3 Control 1 5 2 Aliases 3 1 4 Post Store 1 5 3 Position 1 5 4 Magnification 3 2 Control Master Menu 3 3 Status Menu 1 6 Vertical Adjustments 3 3 1 Mode 1 6 1 VOLTS DIVISION 3 3 2 1 6 2 Position 3 3 3 V Div 1 6 3 Variable Uncalibrated 3 3 4 Probe set 1 6 4 Add 3 35 Timebase 3 3 6 Trigger 1 7 Manually Obtaining a Trace 1 8 Operating Hints 3 4 Display and Trigger Menu 1 8 1 Intensities too low 3 4 1 Probe ratio 1 8 2 Trace off the top or bottom 3 4 2 of screen 3 4 3 Dot Join 1 8 3 Trace not being acquired 3 4 4 Averaging 1 8 4 Trace unstable 3 4 5 Trig Pos n 1 8 5 Trace has flat top or bottom 3 5 Display Intensity 25 Advanced Features 3 6 Reference Trace 2 1 Trigger Control 3 7 RS423 Interface Menu 2 1 1 Selecting Source and Coupling 3 7 4 RS423 Plot Connections 2 1 2 Level 3 7 2 5423 Data Connections 2 1 3 Trigger Point 2 1 4 Slope 3 8 Special Functions Menu 2 1 5 Trigger Mode Norm Auto 3 9 Post Store Master Menu 2 1 6 Trigger Delay 3 10 Save Trace Menu 3 11 Recall Memory Menu 2 2 Capture Facilities 3 12 Plot Menu 2 2 1 Trace Hold 2 2 2 S Shot and Run 4 Performance checking 2 2 3 Acquisition Status AFTS 4 1 Risetime 4 2 Bandwidth 2 3 Display Modes 4 3 Trigger sensitivity 2 4 Cursor Measurements 4 4 Trigger bandwidth 2 4 1 Cursor and Datum Selection 4 5 Timebase calibration 2 4 2 The Cursor amp
26. 1mHz 25 2 78Hz 1 14Hz 532mHz 258mHz 126mHz 62 7mHz Is 5056Hz 2 21 7 1 06Hz 515mHz 253mHz 125mHz 500ms 11 1Hz 4055Hz 2 13Hz 1 03Hz 505mHz 251mHz 200ms 27 8Hz 1104Hz 5032Hz 2058Hz 1 26Hz 627mHz 100ms 55 6Hz 22 7Hz 10 6Hz 5 15Hz 2053Hz 1 25Hz 50ms 111Hz 45 5Hz 2103Hz 1003Hz 5 05Hz 2 51Hz 20ms 278Hz 114Hz 53 2Hz 25 8Hz 12 6Hz 6 27Hz 10ms 556Hz 227Hz 106Hz 5105Hz 2503 Hz 12 5Hz 5ms 1 I1KHz 455Hz 213Hz 103Hz 50 5Hz 25 1Hz 2ms 2 78KHz 1 14KHz 532Hz 258Hz 126Hz 62 7Hz lms 5 56KHz 2 27KHz 1 06KHz 515Hz 253Hz 125Hz 200 15 11 1KHz 4 55KHz 2 13 KHz L 03KHz 505Hz 251Hz 2000 15 27 8KHz 1104K Hz 5032KHz 2 58KHz 1 26KHz 627Hz 100J Ls 55 6KHz 22 7K Hz 10 6KHz 5 15KHz 2 53KHz 1 25KHz 507 18 111KHz 45 5KHz 2103KHz 1003 KHz 5 05KHz 2051 KHz 204 16 278KHz 114K Hz 53 2KHz 25 8KHz 12 6KHz 6 27KHz 10J Ls 556KHz 227KHz 106KHz 5105KHz 2503 KHz 12 5KHz 97 Ls IIIMHz 455KHz 213KHz 103KHz 5005KHz 25 1KHz 27 15 2 78MHz 1 14MHz 532KHz 258KHz 126KHz 62 7KHz 10 18 5 56MHz 2 27MHz 1 06MHz 515KHz 253KHz 125KHz 500ns 11 1MHz 4 55MHz 2 13MHz 1 03MHz 505KHz 25 KHz 200ns 27 8MHz 1104MHz 5 32MHz 2 58MHz 1 26MHz 627K Hz 100ns 55 6MHz 22 7MHz 10 6MHz 5 15MHz 2 53MHz 1 25MHz 450 only 50ns 111MHz 45 5MHz 21 3MHz 10 3MHz 5 05MHz 2 51MHz Table 5 2 1 Filter Frequencies 5 2 5 Integrate Current Trace When button 5 is pressed the display will show the integrated waveform of the selected trace The voltage datum is taken as zero for integration and the cursor reads out the value in Vs
27. 4 Successive presses of this button places the cursor and datum lines on to the displayed traces in turn 1 e channel channel 2 reference off channel etc If any of the traces are not in use the lines skip to the next valid selection 2 4 2 The Cursor and Datum Lines There are three lines as indicated in Figure 2 4 2 Movement of them 15 aCHleved using DATUM and CURSOR buttons as described below Time Datum Cursor Voltage Datum Menu Traces o L J Bh es is AN LAN Y IN TIN BEES Y PEN V ei Post Store 18 Co Control 9L Figure 2 4 2 The Cursor and Datum lines 400 Series Operators Manual Dat Selecting this option on the Dat Pos Mag button 3 allows the position of the datum lines to be controlled using the DATUM buttons 2 DATUM 2 Used for moving the two datum lines CURSOR 5 Moves the cursor to the right and left along the trace Pos Mag These selections on the Dat pos mag button 3 allow the DATUM buttons to control post storage position and magnitude They can only be used with stored waveforms Pressing menu button 1 opposite the restore message will cancel the effect of pos and mag on the selected trace 1 the one with the cursor on it Pos This option on the Dat Pos Mag button 3 allows both X and Y shift to be applied to the trace on which the cursor is placed using the POST STORAGE DATUM keys 2 Mag The vertical magnitude of the sele
28. 400 series DSOs provides the instruments with a fully automatic built Nickel Cadmium battery and charger which allows uninterrupted operation of the DSOs in the event of an AC supply failure and complete operation independent of an AC supply The battery is fully protected against damage from overcharge or over discharge and automatically receives a fast recharge followed by a continuous trickle charge when AC power is restored or re applied to the unit A DSO with the battery option operates as an integral unit All the normal functions of the DSO with the exception of line trigger are available and function according to the main operators manual Full operation of the DSO is also available while the battery is recharging In the following text battery unit refers to the option and DSO refers to the main oscilloscope The circled numbers in this section refer to the numbered controls in figure 6 2 An AC supply is applied to the battery unit This charges the batteries and is linked through the battery unit to power the DSO The battery unit then also provides a DC supply to the DSO for use in the absence of an AC supply Battery Uni Alarm Lamp Conlnucusa Battery luas Or Over tpmperature trip Flash DSO AC supply fault SAFETY must be grounded earth via ground conductor ol p cord supply or via saloty gro E minal Battery or external DC gm Do Hot Remove Covers Dangerous
29. CH2 Gould 400 Series Digital Storage Oscilloscopes Operators Manual GOULD 100Ms sec Oscilloscope 050 Ar Os Mode S iShot Run ce 2 CH2 EXT TRIG Gould 400 Series Digital Storage Oscilloscopes Operators Manual Copyright 2 1990 Gould Inc Instruments Division Gould Electronics Ltd 400 Operators Manual Contents Introduction Getting Started 1d Advanced Features 2 The Menus 3 Performance Checking 4 Waveform Processing 5 Battery Unit Operation GS Alphabetical Summary Fa Appendix 1 Error Messages A 1 Appendix 2 Specification A 22 Appendix 3 Remote Operation A3 Appendix 4 Front amp Back Pictures Service Facilities Contents 400 Operators Manual Introduction 2 5 Plot 2 5 1 Internal Colour Plotter 1 Getting Started 2 5 2 Pens 1 1 Safety and Power Requirements 2 5 3 Pen Changing 1 1 1 International Safety Warning 2 5 4 Paper Selection 1 1 2 Grounding 2 5 5 Paper Loading 1 1 3 Live Parts 2 5 6 Internal plotting 1 1 4 Ventilation and Dust 2 5 7 External plots 1 1 5 Operating Temperatures 2 5 8 Plot positioning and scaling 1 1 6 Power amp Frequency Requirements 2 66 Data Transfer 1 1 7 Fuse Requirements 2 6 1 Syntax 2 6 2 Receiving Data 1 2 Using the Buttons 2 6 3 Error Status 1 3 Start Up Display 1 4 Obtaining a Trace 2 7 Real Time Clock 1 4 4 AUTO SETUP 1 4 2 Channel Selection Off On Inv 3 The Menus 1 4 3 Coupling AC DC Gnd 3 1 Additional Buttons 3
30. Datum Lines 4 6 Vertical Calibration 2 4 3 Making Measurements 4 7 Max Min Alias Detector 400 Series Operators Manual 5 Waveform Processing Functions 5 1 Cursor Measurements 5 1 1 Voltage and Time 5 1 2 5 1 3 5 1 4 Risetime falltime 5 1 5 Overshoot preshoot 5 1 6 Pulse Width 5 1 7 Frequency Period Duty Cycle 5 1 8 RMS 5 1 9 Area 5 2 Trace Manipulation 5 2 1 Filter Frequency 5 2 2 Filter Current Trace 5 2 8 Invert Current Trace 5 2 4 Integrate Signal 5 2 5 Integrate Current Trace 5 3 Trace arithmetic 5 4 Persistence Limits Testing 5 4 1 Limits 5 4 2 Persistence 6 Battery Unit Operation 7 Alphabetical Summary of controls Appendix 1 Error Messages Appendix 2 Specification Appendix 3 Remote DC operation of the DSO Appendix 4 Front and Back Pictures Service Facilities Contents Figure List 2 2 2C 3 4 4 1 5 5 2 1 6 2 1 2 1 6 2 2 2 4 2 4 2 2 5 5 2 5 8a 2 5 8b 3 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 7 1 3 7 2a 3 7 2b 3 8 3 9 3 10 3 11 3 12 5 1a 5 1b 5 1 1 5 1 2 5 1 3 5 1 4 5 1 5 5 1 6 5 1 7 5 1 9 2 5 4 i i i 6 2 A2 2 A4a A4b Single Function Buttons The Toggles Pressure Sensitive Buttons Start Up Display Obtaining a trace An AUTO SETUP Display Horizontal Controls Alias Generation Vertical Controls Trigger Controls Trace Capture with Delay Capture Controls The Cursor and
31. Delay The input impedance is I M ohm in parallel with a capacitance of b 28pF m This is used to remove any DC component from input O signals Suitable input signals i e the bandwidth are from Posna WDY to 20MHz ax Auta Gnd The input signal is internally disconnected from the inputs and T the amplifier grounded A OV reference signal is displayed bi AC cl CM Ext Line E DC The input signal is directly coupled to the instrument so all frequency components of the input signal will be displayed The bandwidth will be from DC to 20MHz 1 5 Horizontal Adjustments Menu Traces 5 Refr Roll X Y ArmiC Stord ALL 1 3 Plot Mode S Shot Run a C HORIZONTAL 4 TIME DIV Mag Position 5 E 6 Cl Post Store 8 C Control Figure 1 4 1 An AUTO SETUP Display Figure 1 5 Horizontal Controls 1 4 2 Channel Selection 13 A channel may be switched on or off with its Off On Inv button If the channel is on its trace can be displayed in either normal or inverted mode Off The channel is deactivated On The trace is a true representation of the input signal Inv The input signal is inverted before being displayed If there is any DC component in the signal this will also be inverted and could cause the trace to disappear from the screen Such an unwanted DC component
32. a These may be shifted and scaled to position the plot exactly over a pre defined grid using the following procedure with reference to figure 2 5 8b The sides of the pre defined grid are X and Y the exact positions of PI and P2 are found by calculating the dimensions A B C and D Measure the vertical dimension of the required grid note this as Y Measure the horizontal dimension of the required grid note this as X U sing these values of X and Y A B C and D can be calculated as follows B 196 X 240 222 800 _ 703X D 310 T TB 90 Measure and mark the exact positions of and 2 from the grid edges using figure 2 5 8b and the values obtained above The PI and P2 points can now be set on the plotter refer to the plotter manual for details 400 Series Operators Manual Advanced Features P2 696 290 2 500 255 lt lt 500 248 Graticule ove Maximum Plot Area 7 20 Figure 2 5 8 Relative Plot Positions Figure 2 5 86 Plot Dimensions Advanced Features 2 6 2 7 2 6 Data Transfer Trace data for either 2 or the reference trace be transferred to and from the 400 oscilloscope and a computer There are four I O commands which are used for the data transfer they are ST1 STI ST3 and ST The first three commands are used to transfer data and the fourth one to interrogate the 400 for its error status 2 6 1 Synt
33. abelled Trace Hold Trace Hold 25 Freezes the relevant trace or traces the moment they are pressed second press releases the trace 6 2 2 2 Single Shot and Run These buttons are used to set the instrument into either a capture and freeze mode S Shot or a free running continuous capture and re capture mode Run S Shot 30 Arms the instrument for a single shot triggered acquisition The Arm d light will be illuminated to show that the button has been pressed Arm d 29 Illuminates after the S Shot button has been pressed it will stay lit until either a valid trigger has been received or until the Run button is pressed Stor d 28 Illuminates on completion of single shot acquisition This is after the instrument has been Arm d triggered and a complete trace acquired The light will stay on until the instrument is re armed by pressing S Shot again or Run is pressed Run 27 This button puts the instrument in continuous capture mode the instrument will automatically rearm itself after each capture is completed so that the display will be updated with each triggered sweep 2 2 3 Acquisition Status AFTS These characters appear on the screen and can be used with the Arm d and Stor d lights to determine the status of the acquisition in progress A Stands for Armed F Indicates that the acquisition store has been filled with enough pre trigger information to be ready for a fresh acquisition T Stands for
34. al safety under extreme fault conditions the DC fuse 1s a high rupture current HRC type This fuse should have a 1500A break capacity 1 2 Using the Buttons see appendix 3 There are three types of buttons The first type usually have only one function when pressed that one function will be activated e g AUTO SETUP 24 See Figure 1 2a The second type are toggles each press of the button either switches something on or off e g Add 10 or selects the next item in a sequence e g Off On Inv 13 See Figure 2b The third type are Pressure Sensitive the effect caused depends upon how hard the button is pressed For example a gentle press of a Pos n 8 button will move the trace slowly If the button is pressed harder the trace will move more quickly See Figure 1 2c 400 Series Operators Manual 1 3 Start Up Display When switched on with the POWER button l the instrument will go through its automatic self calibration sequence and then display information similar to that shown in Figure 1 3 Menu Traces 0 D Post Store C Control 9 CJ Figure 1 3 Start Up Display The trace is visible across the centre of the screen At the top will be the sensitivity of the two input channels and the timebase speed It any input is inactive information for that channel will not be displayed Users with no previous experience of a DSO will find that the 400 responds like a conventional Real Time Oscilloscope w
35. al the 400 will cease receiving as soon as a CR or LF is received and then only transfer the data received to the required store 400 Series Operators Manual For binary transfer the 400 will cease receiving when the amount of data indicated by the length field has been received Unless the selected trace for received data is held or acquisition is not armed the selected memory data could be overwritten almost immediately by a fresh acquisition Note The number base for received data 15 set by the 7X field of the incoming string and not by the menu selection See section 3 7 The strings for the horizontal and vertical ranges must be exactly as follows anything else will result in error status 102 being generated as will sending 50ns to a 400 or 420 50s 20s 10s 5s 2s Is 0 5s 0 28 0 15 50ms 20ms10ms 5ms 2ms lms 0 5ms 0 2ms 0 1115 5005 2005 10us Sus 205 lus O 5ps 0 2us 0 16 50ns 5V 2V IV O SY 0 2V 50mV 20mV 10 5mV 2mV 2 6 3 Error Status If the 400 receives ST it will respond with a decimal error status string as follows 0 No error 96 Invalid command 102 Syntax error 103 Number out of range 104 Length error Binary transfer only 105 Checksum error Binary transfer only If an error condition is detected the 400 will not make the transfer of data between its internal memory the destination 2 7 Real Time Clock 420 and 450 only A real time clock is fitted to the 420 and 450 instrument
36. atic built in Nickel Cadmium battery and charger which allows uninterrupted operation of the DSO in the event of an supply failure and complete operation independent of an AC supply Obtaining a trace is especially simple just connect the signal and press the Auto Setup button the 400 does the rest Having obtained a trace readily accessible datum lines and a cursor make it easy to take automatic timing and voltage measurements directly from the display On the 420 and 450 models the waveform processing function increases the power of the cursor measurements in terms of both capture and post storage analysis and measurement functions The innovative use of ergonomically designed pressure sensitive push button controls provides a combination of precision and flexibility for ease of operation Introduction More advanced features of the 400 series include a com prehensive range of menu controlled functions For example the Display and Trigger menu operates features such as the trigger delay and pre trigger display functions The pre trigger display function allows the signal prior to the trigger point to be captured and displayed Three complete traces can be stored for future use and recalled to the display via the Save Trace and Recall Trace menus respectively With the built in battery back up facility these will be retained even when the instrument is switched off In addition to the above features the 420 and 450
37. ax To receive the data for trace one the computer sends STI The 400 then responds with STI 220m 10us HdataCRLF Where 15 for hexadecimal number base 0 for octal number base for binary number base or nothing for decimal number base Data 1s the trace information as described below CRLF is carriage return line feed If the 400 receives ST3 and the reference trace 1s unused the 400 will respond with ST3 UNUSED Note When data is being sent to the 400 D may be used for decimal number base For decimal octal and hexadecimal the data field consists of 501 data points separated by commas For binary transfer the data field 1s as follows ddddcc Where II is a 2 byte count of the data that follows including the 2 byte checksum This will have the value 01 7 hex or 503 decimal dddd dddd is 501 bytes of trace data cc is a 2 byte checksum of the preceding data including the 2 byte length The most significant byte is sent first for both the length and checksum fields Note that there are no comma separators between data bytes during binary transfer 2 6 2 Receiving Data The computer may send strings to the 400 at any time in the same syntax as above The 400 converts the data into a binary form in an internal memory and when all the data has been collected transfers the entire memory to the destination trace store For decimal octal and hexadecim
38. ax Min glitch detection feature which can be used to detect aliases With dot join on this usually results in a filled in wave envelope being seen on the screen indicating a high frequency See Section 3 A 1 5 3 Position Position 26 These buttons move all traces to the right or left The position of the cursor Section 2 4 is fixed in relation to the trace so it will move with the applied shift With x magnified traces Section 1 5 4 the cursor can be off the part of the trace displayed on the screen To bring it back into view use the CURSOR lt gt buttons 5 1 5 4 Magnification Mag 32 Switches horizontal magnification on or off When switched on a 10 expansion is applied to any displayed trace which will expand around the centre of screen The timebase setting is adjusted to reflect the expansion The instrument displays 50 dots samples per screen division each plotted dot value being obtained from the 512 byte acquisition memory At an expansion of x 10 there are five dots per division 1 6 Vertical Adjustments Each channel has its own set of vertical controls See Figure 1 6 1 6 1 VOL TS DIVISION V DIV 11 Adjusts the sensitivity of the instrument over discrete calibrated ranges from 2m V to 5V per screen division in 1 2 5 steps With a x10 probe the ranges 400 Series Operators Manual are 20mV to 50V per division at the probe tip See Section 3 4 1 If the Uncal light is on then these buttons var
39. ay be used or recharged at temperatures down to O C but repeated recharge below 15 C may adversely affect the battery life The batteries will not be damaged by storage in the discharged state however it is recommended that they are fully charged before being unused for long periods 24 hours operation on charge is recommended before use after the unit has been unused for more than a month at 20 C or a week at 50 C 400 Series Operators Manual 6 6 Independent Operation of DSO In any circumstances 1f the battery facility 15 not required the AC supply link from the battery unit to the DSO can be disconnected and an AC supply fed directly into the DSO In this mode the master power switch 3 7 must be off or the DC cable disconnected from the DSO This mode of operation allows the use of the DSO on an AC supply above the 45 C limit for battery operation but below the 50 C limit for the DSO alone Similarly if the DC cable from the battery unit 15 removed from the DSO an external DC supply can be used to power the DSO For example a high capacity battery could operate the DSO remote from an AC supply for long periods The batteries cannot be re charged from an external DC supply Battery Unit Operation 6 6 Alphabetical Summary 7 Alphabetical Summary of Controls AC As part of AC DC Gnd AC removes DC components from signals of between 4Hz and 20MHz As part of hf rej AC DC it sets AC coupling for the trigger signal
40. be set Menu Traces lt lt RS423 INTERFACE MENU gt gt SPEED 9600 dak i 1 HANDSHAKE rss 2 2c NUMBER BASE HEX OCT BIN BLOCK LENGTH 0 FIXED FORMAT 8 DATA NO PARITY 1 START BIT 1 NO STOP BIT Figure 3 7 An RS423 Interface Menu Data is always output with no parity one start bit eight data bits and one stop bit The data that is output is the complete waveforms including the reference trace plus information about the timebase and volts per division The data is output in a form suitable for HPGL plotters such as the Gould 6120 See section 3 12 SPEED This is selected with button 1 The data rate may be 75 150 300 600 1200 2400 4800 or 9600 baud HANDSHAKE Key 2 is used to select from handshaking Off XON XOFF or CTS RTS NUMBER BASE Button 3 sequentially selects from decimal hexadecimal octal and binary as the number base to be used in any data transmission from the 400 See section 2 6 The value range for the data points for each number base is as follows Decimal Each data point is sent as a signed decimal number 128 represents the bottom of the screen 0 represents the middle of the screen and 128 represents the top of the screen The maximum number of characters per trace transfer is 2522 Octal Each data point is sent as three unsigned octal digits 000 represents the bottom of the screen 200 represents the
41. ce 4 When the has been changed press the left hand button the paper advance button and the carriage will move back to the left hand side ready for the next plot 2 5 4 Paper selection Only use Gould paper Part number 04101165 for a pack of 8 rolls Other paper types may damage the mechanism 2 5 5 Paper Loading CAUTION When loading paper extreme care should be taken not to force any of the plotter mechanism NEVER pull paper through by hand always use the paper advance button to prevent damage to the plotter mechanism 1 With scissors cut the end of the paper square 2 Open the plotter cover by depressing the catch and lifting the cover until it is fully open 3 Remove the shaft from the paper cradle and if the plotter has been used previously remove the plastic or cardboard tube from the shaft Advanced Features 2 5 6 2 5 8 4 Insert shaft through the paper roll and fit the roll into the paper cradle 5 Feed the paper from the top of the roll as shown in figure 2 5 5 below and push it through the slot in the rear of the printer mechanism 6 Press the paper advance button the left hand blue button at the front of the printer assembly until the paper reappears at the front d Feed enough paper through to pass through the top cover ensure that it is running around the mechanism smoothly and that it is straight 7 Close the plotter cover and ensure that it latches shut Figure 2 5
42. ched on the instrument will go through its power up sequence checking the internal calibration 2 Decide to which channel you are going to apply the signal or CH2 3 sure the chosen channel is active by setting the Off On Inv 13 for that channel to On 4 Set the AC DC Gnd button 14 for the chosen chan nel to Gnd 5 If necessary turn that channel s Uncal light out by pressing Var once 15 6 Make sure that horizontal mag is not selected 32 7 Adjust the TIME DIV setting 33 to give a timebase of Sus Set the display Mode 31 to Refr 9 Set the TRIGGER Norm Auto button 20 to Auto 10 Use the CHI CH2 Ext Line button 17 to choose the source for trigger signals 11 Set the trigger coupling with the hf rej AC DC button 18 12 necessary adjust the position of the trace using the Position and Pos n buttons 26 amp 8 13 Ensure that Trace Hold 25 is not selected 14 Select Run 27 15 Apply the signal through a BNC connector to the chosen CH input socket 9 or 12 16 Set the AC DC Gnd button 14 for the channel to either DC or AC as appropriate 17 Adjust the gain of the chosen channel using the V DIV buttons 11 For intermediate settings set Uncal on by pressing the Var button once 15 18 Adjust the timebase setting using the TIME DIV but tons 33 19 If the display is unstable adjust the trigger Level 22 1 8 Operating Hints The followin
43. cted trace can be varied from X4 to XO 062 using the POST STOR AGE DATUM keys 2 The magnification factor is displayed near the top centre of the CRT No horizontal magnification is available using this control but x10 magnification may be applied to all stored traces using the horizontal mag button See Section 1 5 4 2 4 3 Making Measurements The instrument displays at the bottom of the screen the time and voltage difference between the intersection of the horizontal and vertical datum lines and the cursor The choice of points between which to make the measurements can influence the accuracy while the measurements made will always be within the design limits placement of the cursor at the desired position is easier at those points where the slope of the waveform 15 at its steepest For example on a standard sine wave the most accurate measurements of wavelength are likely to be made if they are taken between two OV crossing points 2 5 Plot 2 5 1 Internal Colour Plotter Operation When the internal colour plotter is fitted to the 400 OSO plots of the instrument s display can be sent to it by selecting internal on the Plot Menu see section 3 12 The internal plotter is automatically selected on power up if it is fitted If required the plot output can be directed via the RS423 port to an external plotter by selecting RS423 on the Plot Menu see section 3 12 2 5 2 Pens Only use Gould pens part number 04101175 f
44. d turn the instrument on using the Power button The instrument will then start up in its reset condition This can be confirmed by noting that on power up the instrument performs a complete calibration Amendment to 400 series Operators Manual Part Number 457403 Page 1 of 1 Part No 460150
45. e Master Menu changes the display to the Cursor Measurements Menu figure 5 1 The cursor is used to determine the trace of interest and the cursor and time datum lines define the portion of the trace to be measured Most trace measurements are with respect to the voltage datum line lt lt CURSOR MEASUREMENTS MENU gt gt CALCULATION 1 Freq Period amp Duty cycle CALCULATION 2 Pulse width CALCULATION 3 Voltage amp Time REFERENCE Pulse Width Left Figure 5 1a Cursor Measurements Menu Three calculations are possible using buttons 2 3 and 4 Each calculation is selected from a roll around list containing the following options Voltage and Time Peak Peak Risetime falltime Overshoot preshoot Pulse Width Frequency Period Duty Cycle RMS Area and off A calculation can only be selected once e g if calculation 1 is set to its default of Voltage and time then Voltage and time will not appear in the possible selections for calculations 2 or 3 Waveform Processing 5 1 5 1 1 If any of the calculations are set to either Pulse Width or Risetime lines 5 6 and 7 are displayed The calculation results are displayed in the three lines at the bottom of the trace display figure 5 1b shows an example Cursor measurements on timebase speeds of 200 and 100ns div i e when ETS equivalent time sampling is in operation are only valid on traces that the cursor is on and that are triggered CH2
46. e new operating conditions If the operating conditions are not changed a recalibration 15 initiated at 15 minute intervals alternating between channels 1 and 2 Each calibration takes about one second If the occasional interruption of the normal function of the instrument is unacceptable to the user the Auto cal facility can be disabled as described above Recalibration is then recommended 30 minutes after switch on from cold and additionally if there 1s a significant change in the ambient operating temperature CALIBRATE CURRENT SETUP Pressing button 2 forces the instrument to recalibrate for the vertical range and mode and the timebase range that it is currently set at The actual calibration occurs approximately 2 seconds are pressing the button This feature does not operate when the instrument is in Roll mode FULL CALIBRATION Button 3 forces the instrument to perform a complete internal recalibration ignoring existing information All internal memories are cleared including the instrument status data and any stored traces To obtain the best results from this calibration the instrument must have been operating for a minimum of 1 hour This calibration should only be required if there have been repairs to the signal processing sections of the unit or if the internal battery maintaining the status memories has been totally discharged or disconnected Menus 3 9 REAL TIME CLOCK 420 and 450 only real time cloc
47. e number 1 button In Single plot mode one press of the Plot button will produce one plot output In Auto mode a press of the plot button will initiate a plot The sequence thereafter continues automatically At the end of the plot the trigger circuit is rearmed for the next acquisition and at the end of an acquisition the plot is started An external plotter must have an auto feed facility to function correctly in this mode If it does not then the feed command from the 400 may confuse the plotter PLOT WITH GRATICULE The user has the option of including the screen grid in the plots with On or excluding it with GRAT LINE TYPE A solid or broken graticule can be selected for the plot by successive presses of button 3 PLOT WITH CURSORS If On is selected then any plots made will include the cursor and datum lines Otherwise they will be omitted PLOT OUTPUT This line only appears if the instrument is fitted with an internal colour plotter The internal plotter is automatically selected on power up if it is fitted If required the plot output can be directed via the RS423 port to an external plotter by selecting RS423 with button 5 ADVANCE PAPER Pressing button 6 when the internal plotter is selected causes the paper to be advanced approximately 15mm per press This line only appears if the internal plotter is selected on line 5 400 Series Operators Manual 400 Series Operators Manual 4 Performance Checking
48. e trigger visible can be set with the front panel PreTrig Delay buttons 23 Pre trigger can be set anywhere between 0 and 100 of screen width in steps as small as 0 4 Trig Delay With this set the oscilloscope will acquire a trace following both the specified trigger and a specified delay The amount of delay is shown beside the 7 key Delay is controlled by the PreTrig Delay keys 23 The size of the steps by which the delay can be incremented or decremented is controlled by the TIME DIV keys 1 step size is 0 04 x the time div setting This can be demonstrated by varying both the timebase and delay settings while observing the last two lines of the Display and Trigger Menu See section 3 4 Once set the delay time remains the same regardless of the selected timebase range 65 pre trig Trigger point Trig Delay 22ms Figure 3 4a Trace Capture with Delay Advanced Features 2 1 6 2 2 1 2 2 Capture Facilities The capture facilities allow the traces to be frozen Armd Stord ALL CH1 CN2 AUTO Trace Hold SETUP Figure 2 2 The Capture Controls 2 2 1 Trace Hold There are two ways to freeze the display a single shot capture whereby a full trace is acquired then frozen Section Pre Trigger Displayed trace No Trig Delay Delayed LESTIE 0 1 Advanced Features 2 2 2 2 4 2 2 2 2 or by pressing one of the buttons l
49. ed Both positive or negative pulses can be measured The first pulse between the time datum and the cursor is measured and if the leading edge of the pulse is noisy the noise may be taken as a pulse and be measured rather than the pulse of interest Trace between Time Datum and Cursor scanned for peak to peak value Figure 5 1 6 Pulse Width Measurement Waveform processing 5 1 5 5 1 8 The default percentage points are 50 and 50 Using buttons 5 6 and 7 these values can be changed Button 5 selects the point to be changed either Pulse Width Left or Pulse Width Right When the appropriate point is selected it can be changed by pressing button 6 or 7 as required Both of them can be set from 5 to 95 in 1 steps Percentages set are retained even on power down but are reset to their default vales 1f a full calibration is performed If Risetime 15 also selected as one of the calculations pressing button 5 steps around 4 entries Pulse Width Left Pulse Width Right Risetime Low and Risetime High 5 1 7 Frequency Period Duty Cycle The three parameters frequency period and duty cycle of a waveform are displayed with this selection The voltage datum defines the zero crossing voltage The cursor and time datum must enclose at least three zero crossings If the voltage datum does not cross the trace the mean of the waveform will be taken as the zero crossing line The frequency is the inverse of the period calcula
50. ence trace control RS423 interface and special functions Menu traces Alternately switches between trace display and the last menu selection Post storage master menu Selects menus for fast access to save recall trace and plot output parameters AUTO SET UP Automatically sets the front panel controls to display any applied repetitive input signal for frequencies greater than 20Hz Trigger and timebase priority is CH2 and Line RS423 INTERFACE serial interface port for bi directional waveform data and associated range parameter transfer Baud rate 75 150 300 600 1200 2400 4800 9600 Data bits 8 Parity None Start stop Fixed one start bit one stop bit DIGITAL PLOTTER OUTPUT The instrument can directly output to suitable HPGL format plotters via the RS423 interface port Plot mode Manual or auto selection to output a stored trace Annotation Range and scaling annotation graticule cursors and cursor readout can all be included in the plot output Colors Color pens automatically selected when available Appendix 2 Specification Internal Color Plotter 420 and 450 only Paper type Gould part No 04101165 8 roll pack Paper length 55 metres equivalent to approximately 300 plots Pen type Gould part No 04101175 4 color pack Pen life Minimum of250 metres line length approximately 175 plots WAVEFORM PROCESSING FUNCTIONS 420 and 450 only Cursor Measurements Voltage and Time The cu
51. ent while one source takes over from the other Appendix 3 Remote Operation The diode in series with the external DC source protects the instrument against reverse polarity voltages and allows both the AC and DC supplies to be connected at the same with the source supplying the higher voltage being the one from which current is drawn Table of Annealed Copper wire sizes vs length for O 5V drop at 5 Amp current Diameter Cross Sectional Area Length mm mm M 0 8 0 5 2 9 0 98 0 75 4 35 1 26 1 25 7 25 1 78 2 9 14 5 2 26 4 0 232 2 76 6 0 34 8 3 19 8 0 46 4 3 57 10 0 58 0 TableA3 1 AC from internal External DC transformer from battery unit option or separate DC source FigureA3 2 Appendix 4 Front amp Back Pictures WARNING Switch off power before connecting disconnecting interfaces SAFETY Instrument must be Grounded earthed via protective ground conductor of power cord AC supply or via DC input DC supply Do not remove covers Dangerous voltages present See manual For use by qualified laboratory personnel Pour emploi par le personnel de laboratoire Fig A4a Rear View Fig A4b RS423 Connections 25 24 23 22 21 20 19 18 17 16 15 14 400 Series Operators Manual Siow Blow AC Voltage Fuse Rating Nom Range EC UL CSA 30 osnon 190 26 Frequency 45 70Hz Power 7OW B5VA 1867737 p CAUTION Negative DC terminal is connected to
52. ept no responsibility for instruments arriving damaged Our Sales and Service Department and those of approved distributors and agents are ready to assist you at all times The Gould Service Department and those of approved dis tributors and agents can provide maintenance and repair information by telephone or letter if required UNITED KINGDOM Gould Electronics Ltd Instrument Systems Roebuck Road Hainault liford Essex IG6 3UE Telephone 081 5001000 Telex 263785 Fax 081 5010116 U S A Gould Inc Recording System Division 3631 Perkins Avenue Cleveland Ohio 44114 Telephone 216 361 3315 Telex 1961123 GLD RS UT Fax 216 881 4256 And other Gould Agents and Distributors worldwide Manual Part Number 457400 Notes s GOULD Electronics 400 Operators Manual Amendment Sheet November 1990 400 System Reset Should the system memory become corrupted the instrument could lock out the front panel operation or begin to behave erratically Since the internal system variables are held in non volatile memory turning the set off an on again may not clear them In this unlikely event a system reset may be necessary A system reset should only be used as a last resort as all the internal memories will be cleared erasing all reference traces calibration details and set up details To perform a system reset switch the instrument off Press and hold the Hold All and the Plot buttons Keep these buttons pressed an
53. es 1 3 2 CA 4 5 C 6 5 7 Post Store 8 Control 9 Figure 3 5 Display Intensity Menu ALPHA The brightness of all the alphanumerics will be adjusted The number 3 key increases the intensity and the number 4 key decreases it GRAT The brightness of the graticule or grid will be adjusted The number 5 key increases the intensity and the number 6 key decreases it The Menus 3 5 3 6 3 6 Reference Trace The menu provides the option of temporarily storing a trace for comparison with the two Channels It will be lost when it is replaced with an alternative trace Menu lt lt REFERENCE gt gt 0E REFTRACE 8 On 1 COPY TRACE 1 TOREFTRACE 2 COPYTRACE 2 TOREFTRACE 3 4 5 E 6 Co 7 Ll Post Store e C Control 9 Co Figure 3 6 Reference Trace Menu To copy a currently displayed and held trace into the reference trace simply press either button 2 or button 3 depending on whether the held trace is in Channel or Channel 2 respectively A copy of the trace will then be automatically taken If the trace is not held prior to pressing the button a fresh acquisition will be made before the copy is taken To display a previously stored reference trace use the button to toggle the selection to On Menus 3 3 7 RS423 Interface Menu This menu allows the parameters of the RS423 output to the remote plotter or other data handling device to
54. etween the cursor and time datum measured with respect to the voltage datum Trace measured between Time Datum and Cursor oa gt Figure 5 1 3 Measurement waveform Datum defines 096 Cursor Defines Figure 5 1 4 Risetime Measurement The default percentage points are 10 and 90 Using buttons 5 6 and 7 these values can be changed Button 5 selects the point to be changed either Risetime High or Risetime Low When the appropriate point is selected it can be changed by pressing button 6 or 7 as required Low can be set from 0 to 49 in 1 steps and high from 51 to 100 also in 1 steps Percentages set are retained even on power down but are reset to their default vales if a full calibration is performed If Pulse Width 15 also selected as one of the calculations pressing button 5 steps around 4 entries Risetime Low Risetime high Pulse Width Left and Pulse Width Right 400 Series Operators Manual 5 1 5 Overshoot preshoot Position the cursor and the time datum at the 0 and 100 points of the waveform The software calculates the overshoot as a percentage of the voltage difference between the 0 and 100 points Time Datum Defines 0 Overshoot Figure 5 1 5 Overshoot Measurement 5 1 6 Pulse Width The software measures the time between the 50 points of a pulse The time datum and cursor should be positioned on either side of the pulse to be measur
55. g list gives some of the more commonly met problems in operating digital oscilloscopes how to correct them and a brief explanation of what was wrong Getting Started 1 6 4 1 8 5 Y ou may need to consult later sections of the manual as not all of the operating features have been discussed so far 1 8 1 Problem Traces and Alphanumerics very dim or completely disappeared Intensities too low Press the control button 7 to get the control master menu then press numeric button 3 to select the intensity menu Further presses of numeric button 3 will increase the brightness of the alphanumerics on the display The traces can now be intensified using numeric button I Note display not become visible until the numeric button 3 has been pressed several times 1 8 2 Problem Trace off the top or bottom of the screen Too much vertical shift correct with that channel s Pos n buttons 8 Input has large DC offset AC couple input signal Correct with Pos n buttons 8 Usea less sensitive range 1 8 3 Problem Trace not being acquired Instrument in single capture mode Press Run 27 Trigger level incorrect Select Auto and DC trigger then adjust the level control until the trigger level indicator bars are lined up with the centre of the trace Trigger source on the wrong input Change trigger source CH1 CH2 Ext Line 17 Trigger coupling on an unsuitable setting Change trigger coupling hf
56. ge considerably with small changes in input frequency 4 Carefully adjust the frequency of the signal generator to produce a sine wave of approximately 2 to 5 cycles This is an alias Select Max Min function from the Display Trigger Menu If s functioning correctly and dot join is off then two roughly horizontal lines will be displayed These will be at the peak levels of the input signal 400 Series Operators Manual 5 WAVEFORM PROCESSING FUNCTIONS 420 and 450 only All the waveform processing functions are accessed through the Post Storage Master Menu Selections 1 2 and 3 on this menu perform as described in section 3 9 to 3 12 Selections 4 to 7 provide the waveform processing functions When performing any waveform processing that modifies a displayed trace the new data could be overwritten almost immediately by a fresh acquisition unless the selected trace is held or further acquisitions are prevented e g the instrument is in single shot mode and the trace stored or no triggers are provided 5 1 Cursor Measurements The 400 DSO has 3 user controlled lines for use with this section of facilities Their operation is fully described in section 2 4 The cursor is moved along the selected trace using the lt P cursor buttons 5 the two datum lines are moved using the datum buttons 2 the time datum line with and the voltage datum with A and Pressing button 4 on the Post Storag
57. gle shot for the set number of acquisitions weighted average Peak detection Minimum pulse width Zus 100 probability of capture Operates on timebase range 100p s div or slower MEMORY Waveform memory 3 reference memories are selectable for waveform data storage These memories are Nonvolatile Set Up The control set up is retained on memory during power down Retention time The memory support is trickle charged and will retain information for 1 month after power down ON SCREEN MEASUREMENTS and ALPHANUMERIC DISPLAY Datum Lines Horizontal and vertical full screen amplitude time and voltage datums Appendix 2 Specification Cursor The measurement cursor can be assigned to a trace and measurements made in time and voltage with respect to the datums Cursor measurement display 6 Voltage and 6 Time displayed on screen Accuracy Voltage 2 5 of reading 1 digitising level 1 30 of a division Time 0 01 of reading 1 digit Resolution Voltage 0 4 of F S D Time 0 2 of F S D Trigger Indication On screen trigger level and trigger point indication Alphanumerics Display on screen to indicate vertical sen sitivity and input coupling for each channel timebase speed and pre trigger or trigger delay Arrow for off screen indication of trigger point and traces MENU SELECTION Control master menu Selects menus for prime functions Status display and trigger facilities display intensity refer
58. he following messages will be displayed as appropriate NO LIMITS DISPLAY IN XY NO XY WHEN LIMITS DISPLAYED NO LIMITS DISPLAY IN X MAG NO LIMITS TESTING WITH X MAG NO X MAG WHEN LIMITS DISPLAYED NO X MAG WITH LIMITS TESTING Also Display Limits cannot be turned on if persistence is on Trying to select this mode results in the message NOT WHEN PERSISTENCE ON A record of all failing traces can be automatically plotted by setting the limits testing mode to stop on fail and selecting Auto Plot from the plotter menu Any acquired trace that then falls outside the limits will be plotted If the plot button is not pressed to initiate a continuous sequence only the first failing trace will be acquired and plotted 5 4 2 Persistence The 400 is not capable of variable persistence but either the number of acquisitions accumulated before the display is cleared or the absolute time between display clearances can be set from the Persistence Limits Menu The choice of Persistence for time or number of acquisitions 15 made using button 5 with the actual time of number of cycles set by button 6 or 7 as appropriate When using the persistence mode the trigger level and position markers are not displayed If Display Limits is on then persistence cannot be selected and the message NOT WHEN LIMITS DISPLAYED is shown if button 5 is pressed 400 Series Operators Manual 6 0 Battery Unit Operation The 400 107 battery unit option for the
59. hile it is repetitively triggered but in the absence of further valid triggers it retains the last trace for continuous display 1 4 Obtaining a Trace See Figure 1 4 1 4 1 AUTO SETUP o display an input signal connect it via either the CHI socket 9 or the CH2 socket 12 and press AUTO SETUP 24 Assuming you ve applied a regular signal say 2kHz sine wave with an amplitude of perhaps 5V peak to peak it will almost immediately be represented on the display An example is shown in Figure 1 4 1 It the display is very dim or has completely disappeared see section 1 8 1 AUTO SETUP will attempt to arrange the display so that two to five complete cycles appear with the amplitude set so that the height of the trace is between two and five screen divisions Also it selects Auto trigger to ensure that the screen is frequently updated and a trace will be visible If signals are connected to both channels the highest amplitude takes priority 400 Series Operators Manual Getting Started 1 4 2 1 5 1 4 1 4 3 Coupling AC DC Gnd 14 400Ms sec Oscilloscope DSO 400 E These buttons control the type of coupling between the input signal fell X Y Armi O ALL CHI AUTO i Mode S Shot Run Trace Hold SETUP and the instrument DC is the most generally applicable and EIC AUTO SETUP will normally set this control to DC where HORIZONTAL TRIGGER possible Mag FOSUDn Pre Trig
60. impaired if for example the instrument shows visible damage or fails to perform the intended measurements correctly 1 1 2 Grounding THE INSTRUMENT MUST BE GROUNDED AC The instrument must be operated with a protective ground connected via the yellow green conductor of the supply cable This is connected to the instrument before the line and neutral connections when the supply plug is inserted into the socket on the back of the instrument If the final connection to the supply is made elsewhere ensure that the ground connection is made before line and neutral DC If the unit is disconnected from the AC supply and powered from an isolated DC source or the internal battery unit the unit will not be grounded Independent provision must be made to maintain the case at a safe potential by grounding the safety ground terminal on the DSO rear panel The safety ground terminal is connected to the instrument case to the ground of the input signals outer of the BNC connectors and also internally to the negative side of the DC supply WARNING Any interruption of the protective ground conductor inside or outside the instrument is likely to make the instrument dangerous Intentional interruption is prohibited Signal connections to the instrument should be connected after the ground connection is made and disconnected before the ground connection is removed i e the supply lead must be connected whenever signal leads are connected 1 1
61. instru ments have a built in 4 colour plotter and a battery backed Real Time Clock This provides a simple and convenient method of obtaining permanent hard copy plots of the screen display The plots will contain the date and time of acquisition together with the date and time of plotting The 450 has all the features of the 420 and has a signal bandwidth of 50MHz and an extra timebase range of 5Ons div Numbers circled in the text refer to the controls shown on the front panel picture in Appendix 3 Getting Started 1 1 1 1 6 1 1 Safety and Power Requirements 1 1 1 International Safety Warning as required for 348 Cat I This instrument has been designed and tested in accordance with IEC publication 348 and has been supplied in a safe condition This manual contains information and warnings which must be observed to keep the instrument in a safe condition The instrument should not be switched on if it is damaged and it should not be used under wet conditions For the correct and safe use of this instrument it 1s essential that both operating and service personnel follow generally accepted safety procedures in addition to the safety precautions specified in this manual Whenever it is likely that safety protection has been impaired the instrument must be made inoperative and be secured against any unintended operation Qualified maintenance or repair personnel should be informed Safety protection is likely to be
62. it fitted and operates from line voltages of 90V to 130V and 190 to 265V at 45 to 400Hz Under the extreme conditions of 90V and 45Hz the instrument will still operate correctly even if there is a half cycle dropout in the line supply The instrument may be powered from a direct current supply in the range 12V to 33V The unit cannot be damaged by applying power to both inputs simultaneously Before connecting the instrument to the supply ensure that the rear panel AC supply voltage selectors are set to the appropriate voltage Access to the voltage selector can only be made if the AC supply connector is removed and is by hinging open the panel connector from its top edge The selector barrel can then be moved to the required setting This same operation provides access to the AC supply fuse which must be changed to suit the supply voltage as shown in table 1 1 7 The AC power connection is via a standard IEC CEE 22 connector and the DC power input is via the supplied 0 25 spade connector Gould part No 457839 See appendix 4 for polarity details 400 Operators Manual Getting Started 100Ms sec Oscilloscope DSO 400 Helt ALL EN AUTO Mode SETUP SiShot Run 24 ta o o E TIME DIV Co oo T g Post Store 42 Control 9417 MENUS CH2 EXT TRIG 280 400v ph sf Mode setup oo
63. it Data 4 CTS Clear to send 5 5 Request to send 7 OV Signal Ground 9 OV Ground Table 3 7 1 Standard RS423 Pin Connections 400 6120 HP7475 2 Figure 3 7 1 400 to Gould 6120 or HP7475 Cofdctions 3 7 2 RS423 Data Connections To connect the 400 to a computer use the connections shown in figure 3 7 2a or figure 3 7 2b A prewired cable for each of these arrangements is available part number 0410 9248 for the PC XT and part number 0410 1247 for the AT 400 Series Operators Manual 400 O1 C n Figure 3 7 2 400 to Connections 400 N OA J o CO Figure 3 7 2b 400 to IBM A T Connections The Menus 3 8 3 8 Special Functions This menu controls the selection of auto calibration and can force the instrument to perform a full calibration Menu lt lt SPECIAL FUNCTIONS MENU gt gt o c AUTO CAL Disable ico CALIBRATE CURRENT SETUP 2 C FULL CALIBRATION 3 3 B 4 ca 0189 10 20 31 5 Co DEC 6 Co SET DATE amp TIME 17 Post Store 8 Co Control 9 55 Figure 3 8 Special Functions Menu AUTO CAL successive presses of button I enables and disables the instrument s automatic re calibration procedure When Auto cal is enabled the change of any vertical or timebase range will after a 2 second pause initiate a calibration of th
64. iv to 50s div in a 1 2 5 sequence of values Alphabetical Summary Trace Hold 25 Freezes the relevant trace or traces until pressed again Trig d 2 1 This lights up when the instrument is receiving valid triggers Uncal Controlled by the Var button When lit the coarse setting of the attenuator remains unchanged but a variable gain is applied to the input signal This control applies attenuation in the range of 1 to 0 4 Thus with an initial setting of 1 V the actual sensitivity of the channel may be set anywhere between 1 V and 2 5V per division The V DIV buttons are used to vary the sensitivity Var 1 5 Toggles between Uncal amp Cal V DIV 1 1 Adjusts the sensitivity of the instrument over discrete calibrated ranges from 2mV div to 5V div in 1 2 5 steps With a x10 probe the ranges are 20m V div to 50V div at the probe tip Input voltages must not exceed 400 peak If the Uncal light is on then these buttons control the sensitivity over an uncalibrated continuous range of values X V mode takes the CH1 X input as the x horizontal component and the CH2 Y input as the y vertical component 1 9 Selects triggering on positive or negative slopes Appendix 1 Error Messages Appendix 1 Error Messages When something is wrong an error message will be displayed in inverse text near the bottom of the display Also in some cases a message appears to confirm that an action has occurred Brief explanati
65. k 1s set using buttons Menu The entire date and time is displayed with one section highlighted The highlighted element is selected using button 5 and can then be increased or decreased using button 4 or 6 as appropriate Once the correct date and time has been set pressing button 7 enters the data This makes it easy to set a time that is a few seconds in advance of real time and then press button 7 at a time signal If the menu is exited without pressing button 7 then the date and time will remain unchanged The clock is kept running even with the power discon nected for at least ten years by its own internal battery back up Note No channel calibrations will be performed if the instrument is armed in a data capture cycle continuous roll mode or if Auto cal is disabled they will simply be postponed until these conditions end Full calibration is always available If the unit is unable to complete any of the above self calib rations an error message will appear See appendix 1 These messages should only occur if there is a major fault requiring the unit to be serviced When performing a full calibration connect a SON termination to the Ext Trig input This ensures that the trigger input 1s correctly calibrated for a SON source signal 400 Series Operators Manual 3 9 Post Storage Master Menu The Post Storage Master Menu provides access to three further menus which control the operation of the three battery backed
66. middle of the screen and 377 represents the top of the screen The maximum number of characters per trace transfer 15 2023 Hexadecimal Each data point is sent as two unsigned hex digits 00 represents the bottom of the screen 80 represents the middle of the screen and 400 Series Operators Manual FF represents the top of the screen The maximum number of characters per trace transfer is 1522 Binary Each data point is sent as a single byte 00000000 represents the bottom of the screen 10000000 represents the middle of the screen and 11111111 represents the top of the screen The maximum number of characters per trace transfer is 525 BLOCK LENGTH Successive press of button 4 changes the block length from 0 to 80 in steps of 10 i e the sequence 0 10 20 30 40 50 60 70 80 0 A block length of 0 selects infinite length blocks During data output from the 400 if the next value to be sent would exceed the block length then a CRLF is sent instead of the comma Block length has no effect on binary transfers all bytes of data are always sent 3 7 1 RS423 Plot Connections The RS423 port is configured at the factory as shown in table 3 7 1 The instrument can be connected to a Gould colorwriter 6120 or a HP7475 plotter using the Gould plotter cable part number 0409 1232 The connections of this cable are shown in figure 3 7 1 Pin No Description 1 OV Protective Ground 2 RXD Receive Data 3 TXD Transm
67. n Plot 3 4 Produces plot of the current display suitable plotter If a plot is in progress pressing this button will abort it Pos Part of Dat Pos Mag 3 this allows the trace on which the cursor is placed to be shifted using the POST STORAGEIDATUM keys Pos n 8 Moves that channel s trace vertically Position 26 Moves all traces horizontally Post Store 6 Selects the post storage master menu POWER 1 Used to switch the instrument on or off 400 Series Operators Manual Pre Trigger 23 Used in conjunction with the menus to control the degree of pre trigger Refr Refreshed mode is the normal oscilloscope mode whereby the trace is plotted from left to right Roll This display mode operates like a chart recorder the display scrolls from right to left as the trace 15 acquired Run 27 Puts the instrument in continuous capture mode the instrument automatically re arms itself after each acquisition Sec 3 3 Increases the horizontal TIME DIV Select Trace 4 Places the cursor onto a displayed trace S Shot 3 0 Arms the instrument for a single shot triggered acquisition sweep capture The Arm d light will be illuminated to show that this button has been pressed Stor d 28 Illuminates completion of a single shot acquisition It will stay lit until the instrument is re armed or until Run is pressed TIME DIV 33 Controls the sweep rate of the trace The timebase can be varied from 100ns d
68. n of DSO from fully charged battery 1 5 hours minimum 90 recharge time from full discharge 5 hours maximum Battery life to 70 capacity 200 complete discharge cycles at 209 100050 discharge cycles at 20 AC supply range 90 to 130V or 180 to 265V 45 to 400Hz Indication provided for Battery in use discharging Battery on fast charge Battery on standby charge Alarm conditions 400 Series Operators Manual ENVIRONMENTAL Temperature Full Specification 15 C to 35 C Operating 0 C to 50 C 09 to 45 C with battery unit Storage 10 C to 70 C 100 to 50 C with battery unit Humidity Operating IEC 68 2 Ca at 45 C with 95 RH Non operating IEC 68 2 Db cycling 25 C to 45 C with 95 RH 6 cycles 144 hours Vibration MIL spec 8100 Random frequency vibrations of 5 500Hz at 1g rms for 15 minutes IEC 68 2 6 Test 15 cycles of I minute duration 10 to 55Hz at 0 6mm peak to peak displacement in each of the three major axis 4g at 55Hz Safety Designed for IEC 348 Cat standard EMC EMI to BS6527 VDE 0871 Class A ESD 10kV to IEC 801 2 BS6667 2 MISCELLANEOUS Calibrator 1V peak to peak 1 frequency approx 1 KHz calibration signal on front panel Ground Front panel ground reference POWER REQUIREMENTS AC Voltage 90 to 130V or 190 to 265V Frequency 45 to70 Hz 400Hz operation is available as an option DC Voltage 12 to 33V Power 85V A170W approx Appendix 2 S
69. nerated when the selected source signal passes through the chosen trigger level This transition may be either on a rising or a falling edge The rising edge is considered to be a positive slope and the falling edge a negative slope 19 This button selects positive or negative slope triggers 2 1 5 Trigger Mode Norm Auto The trigger system operates in either Normal or Auto mode In Normal mode display captures can only occur when a valid trigger input has been received In Auto mode if no valid trigger has been received for some time the instrument will generate its own trigger and initiate a capture This ensures that the screen is constantly updated irrespective of the input signal However if valid input triggers are received at a rate of 20Hz or more the instrument will start all captures with these triggers and not generate its own Auto Norm 20 This button selects which trigger mode the instrument is operating in Trig d 21 This LED lights up when the instrument is receiving valid trigger signals 400 Series Operators Manual 2 1 6 Trigger Delay The amount of data which is acquired for display before or after the trigger is determined by the pre or post trigger delay selected see figure 2 1 6 The value of this delay is shown in the bottom right hand of the trace display Pretrig This allows a section of the trace that occurred before the trigger point to be included in the display The amount of pr
70. nit reverts to standby charge mode This replenishes approximately 5 of the total battery capacity per hour and is maintained continuously to hold the batteries in the fully charged state The batteries will be charged by the AC supply whether or not the DSO itself is turned on When AC is applied either indicator 3 9 or indicator 40 will be illuminated to show the charge mode Indicator 3 9 shows that the battery is on fast charge and indicator 40 shows that the battery 15 on standby charge No harm can be caused to the batteries by leaving them on standby charge for indefinite periods although if they have been left in this mode for a long time one cycle of full dis charge and fast recharge may be required to obtain maximum capacity 400 Series Operators Manual Limited battery capacity is available to operate the DSO if the AC supply is removed for any reason during fast charge After full discharge the battery capacity will be approximately half the elapsed recharge period If the unit is used outside the temperature range of 15 C to 35 C the normal operation may be limited as discussed in section 6 5 6 4 Alarm Conditions The alarm lamp 3 8 will flash if the DSO attempts to draw power from the batteries while an AC supply is present 1 when the DSO should operate from the AC supply This condition only occurs if the interconnecting AC cable is not connected or the DSO s AC supply fuse 15 open
71. on Filter 6 selectable stages of low pass filter for each timebase range Invert Inverts the trace about the voltage datum Integrate Calculates the indefinite integral and displays the resultant waveform A scaling factor of xl x0 5 x0 2 or x0 1 can be applied to the integrated waveform Trace Arithmetic Add Adds any two traces and displays the result in a selected trace Subtract Subtracts any two traces and displays the result in a selected trace Multiply Multiplies any two traces and displays the result in a selected trace A scaling factor of xl x0 5 x0 2 or x0 1 can be applied to the multiplied waveform Limits testing Tests a waveform with respect to two definable limit waveforms and will display a TEST FAILED message if the acquired signal fall outside the limits Acquisition can be continuous or stop on fail Persistence Either the time or number of acquisitions between screen clearances can be set to give a persisted trace display Times of 0 5 2 5 15 30 or 90 seconds or multiple acquisitions of 10 20 50 100 200 or 500 traces can be selected Both options can be set to infinity to give a permanent persistence display REAL TIME CLOCK 420 and 450 only 24 hour time and date set via a menu Printed out on plots to give a permanent record of acquisition time The time and date is maintained for approximately ten years with the instrument s power disconnected BATTERY UNIT 400 107 Operatio
72. ons of when these messages occur are given below in alphabetical order 1 CALIBRATION DISABLED If Calibrate channel or 2 is pressed when Auto cal is disabled LEVEL FIXED WHEN SOURCE LINE If the trigger level controls are touched when line trigger is selected NO ADD IN XY MODE If trying to select ADD when in X Y mode NO ADD WHEN HELD If the add button is pressed when either or both CH1 or CH2 are held NO BINARY WITH X ON X OFF If X ON X OFF is selected and binary number base is also selected NO CURSORS IN XY If either the Datum or Cursor position keys or the select trace button is pressed when in X Y mode NO HORIZONTAL MAG If the post storage lt I or I keys are pressed when the cursor and X MAG are on NO LIMITS DISPLAY IN XY If limit display is turned on while the instrument is in X Y mode NO LIMITS DISPLAY IN X MAG If limit display 15 turned on while the instrument is in X MAG mode 10 NO LIMITS TESTING ON REF TRACE If limit testing is turned on while the cursor 15 on the reference trace 11 NO LIMITS TESTING WITH X MAG If limit testing is turned on while the instrument is in X MAG mode 12 NO POST STORAGE IN XY If the cursor 15 selected and then the unit is switched to X Y mode and then a post storage key is pressed 13 NO TRACE SELECTED If the cursor is off and either the restore cursor position or post storage movement keys are pressed 14 NO X MAG IN ACTIVE ROLL a If the key i
73. or a pack of 4 1 of each colour Advanced Features 2 4 3 2 5 5 The normal pen sequence is Pen No Colour 1 Black 2 Blue 3 Green 4 Red The pen holder is colour coded with this colour sequence When pens are fitted in this order trace 1 the border and all the alphanumerics are plotted in black trace 2 in blue the reference trace in green and the graticule in red The cursor and datum lines and their measurements are plotted in the same colour as the trace to which they relate The cursor colour also applies to the HPGL output on both the 420 and 450 2 5 3 Pen Changing Underneath the plotter lid at the front of the plotter there are two small blue buttons The right hand button when viewed from the front of the OSO 16 the Pen change button and the left hand one is the paper advance button CAUTION When changing a pen extreme care should be taken not to damage any of the plotter mechanism NEVER move the pen carriage by hand To change a pen ensure that the instrument is switched on and then proceed as follows l Press the pen change button once This rotates the pen carriage and moves the carriage to the right hand side of the plotter 2 Gently press the white grooved eject lever towards the front of the instrument The top pen will be ejected from the pen carriage and can be removed from the plotter Insert the tip of new into carriage guide hole Gently snap the other end of the pen into pla
74. pecification WEIGHT 400 5 5Kg 121b approx 420 450 6 5Kg 14 216 approx 400 with battery unit 11 7Kg 25 716 approx 400 and 450 with battery unit 12 7Kg 27 9Ib approx DIMENSIONS See Figure A2 ACCESSORIES SUPPLIED Operating manual Line cord DC power connector OPTIONAL ACCESSORIES Rack mounting kit Carrying case soft padded Carrying case hard foam lined Front facia cover Accessory Pouch Service manual Probe DC to 100MHz switched x 1 and x 10 Probe DC to 250MHz 1200V x 100 Probe DC to 7MHz 15kV x 1000 External TV Trigger Unit PN 04090490 PN 04101221 PN 04101222 PN 04101220 PN 04101223 PN 04101224 PBD PBI7 PB27 Appendix 2 Specification 400 Series Operators Manual eo Colour Plotter If Fitte 135 Battery Unit If Fitted OOOO SSS SSS SHSSSSSSSSSSSSSSSHSSESSSSESSSSSESESEGESEZESSESESESES Figure 2 400 Family Dimensions 400 Series Operators Manual Appendix 3 Remote DC Operation of the 400 series DSOs As well as the possibility of having an internal battery unit option 107 see section 6 the 400 series DSOs can be operated from external DC voltages between 11 5 and 33V measured at the DSO This has the advantage of uninterruptible operation which an oscilloscope powered from an inverter type of DC supply does not have Inverter type DC supplies are powered by and generate power the absence of
75. point is indicative of a major system fault and the instrument should be ser viced immediately 4 6 Vertical Calibration Equipment required Oscilloscope calibrator Bradley type 192 or similar Coaxial cable Connect the vertical calibration output of the oscilloscope calibrator to the 400 through the coax cable l Set the timebase to 500lLs per division and select 5m V per division for the input channel 2 Set the calibrator to give 25mV peak to peak 1 e 5 screen divisions Adjust the trigger level to give a stable picture 4 Switch the cursor on 400 Series Operators Manual The peak to peak measurement should be 25m V to within 3 and the trace should be 5 divisions high to 0 1 divisions These measurements should be repeated on all the attenuator ranges each time setting the calibrator to 5 screen divisions for the selected range 4 7 Max Min Alias Detector Equipment required Signal generator Tektronix SG503 or similar 50 Ohm coaxial cable 50 Ohm terminator Connect the signal generator to an input channel through the coax and the terminator which should be at the 400 end of the cable 1 Set the timebase to 500ns per division and select 100m V per division on the input channel 2 Set the generator to give approximately 5 divisions at 1 MHz and adjust the trigger level to give a stable trace 3 Select 20115 per division on the timebase You should notice that the screen picture will chan
76. r 4 men polation and the trigger delay function lt DISPLAY AND TRIGGER gt gt CH1 x100 1 3 4 1 Probe Ratio An independent probe attenuation ratio j can be set for each of the two input channels with aM 2 2 successive presses of buttons 1 and 2 The ratios IMAX MIN om easel or 3 available are xl x10 and x100 Thereafter probes of the DOT JOIN Off 4E chosen ratios may be attached to the appropriate inputs the new sensitivities at the probe tip will be displayed SE correctly 6 j u TEP 8us SET E DI 3 4 2 MaxiMin Using number 3 key the or glitch Ue SET BY TIMED 2 A Post Store detection function can be switched on or off 8 Control The Max Min function is designed to detect narrow 9 E glitches which may occur between samples It operates Figure 3 4 Display and Trigger Menu with on the signal before it is placed in the acquisition store Trigger Delay Selected and can detect very narrow glitches down to 2fLs wide Any glitches detected will at least be displayed as a spike They will be detected whether they are positive max or negative min The function works in the timebase ranges of 100 microseconds per division down to 50s per division 3 4 3 Dot Join Button 4 selects the dot joining function On some X magnified or high speed traces gaps can be visible between the sample points if Off is selected
77. return the display to the original stored waveform lt lt TRACE MANIPULATION MENU gt gt FILTER FREQUENCY 556Hz FILTER CURRENT TRACE INVERT CURRENT TRACE INTEGRATE SCALING KOS 0 02 x04 INTEGRATE CURRENT TRACE RESTORE 7 Figure 5 2 Trace Manipulation Menu 5 2 1 Filter Frequency The trace can be filtered by a single low pass filter and the 3dB point displayed on the trace display The frequency of the filter applied to the waveform when button 2 is pressed is selected using button 1 One of six filter stages can be chosen from the roll around list The actual frequencies available depend on the current timebase as shown in table 5 2 1 5 2 2 Filter Current Trace Pressing button 2 causes the software to perform the filtering 5 2 3 Invert Current Trace If button 3 is pressed the selected trace will be inverted about the voltage datum The original trace can be Restored using button 1 5 2 4 Integrate Scaling To allow an integrated waveform to fit on the screen a scaling factor can be applied to the integrate function Pressing button 4 steps around the factors xl xO 5 xO 2 and xO 1 The selected factor is highlighted 400 Series Operators Manual Waveform Processing 5 2 5 5 3 Timebase F1 F2 F3 F4 F5 F6 50s 111mHz 4504mHz 21 3mHz 10 3mHz 5 05mHz 2 51mHz 20s 278m Hz 114mHz 53 2mHz 25 8mHz 12 6mHz 6 27mHz 10s 556mHz 227mHz 106m Hz 51 5mHz 25 3mHz 12 5mHz 5s 1 11Hz 455mHz 213mHz 103mHz 50 5mHz 25
78. rom AC Supply Figure 6 Battery Unit Interconnections Battery Unit Operation 6 2 6 5 6 2 DSO Battery Operation MASTER Battery Unit 400 107 POWER SAFETY arging Using EC JEL On Alarm fast srdby batery ien See rear panel Figure 6 2 Battery Unit Front panel indicators If no AC supply is available the DSO can be powered from the battery unit simply by turning both the Master power switch 3 7 and the DSO power switch 1 on If the DSO is in use on an AC supply that is interrupted the operation of the DSO is uninterrupted as it changes to DC operation Whenever the batteries are supplying power to the DSO the Using battery lamp 4 1 is illuminated When the batteries approach full discharge their output is automatically cut off to prevent damage due to deep discharge In this state no lamps on the battery unit will be illuminated similarly there will be no lamps illuminated if there 15 no AC supply and the DSO 15 switched off whether or not the battery unit 1s switched on 6 3 Battery Recharge To recharge the batteries the master on off switch 3 7 on the front of the battery unit must be on and AC power supplied to the rear socket After any period of battery operation the battery unit will power up in fast charge mode when the AC supply is restored or re applied After a time period dependant on the discharge time which allows at least 80 of the charge withdrawn to be replaced the u
79. rsor measures the voltage and time relative to the voltage and time datum lines respectively Peak Peak Calculates peak to peak voltage of the waveform bracketed between the time datum and cursor Max Min Displays maximum and minimum voltage excursions of a waveform relative to the voltage datum position The cursor and datum bracket the waveform of interest Risetime falltime Calculates the rise or fall time between the 10 and 90 points of a signal The 0 and 100 points are set by the cursor and time datum Overshoot preshoot Calculates the over or pre shoot of a signal as a percent of the 100 point The 0 and 100 points are set by the cursor and time datum Pulse Width Calculates the time between 50 points of a pulse with the pulse being bracketed between the time datum and the cursor Frequency Period Duty Cycle Calculates the average frequency period and duty cycle of a waveform Uses either the voltage datum as the zero crossing point or the mean of the waveform The cursor and time datum set the limits of the area of interest RMS Calculates the root mean square RMS voltage of a waveform bracketed between the cursor and time datum The voltages are calculated with respect to both the voltage datum DC RMS and the mean of the waveform AC RMS Area Calculates the area under a waveform bracketed bet ween the cursor and the voltage and time datum lines 400 Series Operators Manual Trace Manipulati
80. s This enables the current date and time together with the date and time of acquisition to appear on any screen plot and to be transferred to and from a computer if the data transfer facility is used See section 2 6 When trace data is transferred to the DSO the date and time are checked to ensure that they are valid and syntax error 102 is returned if they are invalid The clock will be kept running for at least ten years even with the power disconnected by its own internal battery back up The date and time are set via the special functions menu See section 3 8 400 Series Operators Manual 3 The Menus The menu structure is summarised in Figure 3 The numbers 1 to 9 refer to the numeric buttons used to select the particular menus and menu items Section 3 1 1 All front panel controls remain live when menus are displayed allowing the control status to be changed at any time 9 Control Master Menu 1 2 5 Status Display and Display Reference RS423 Special Trigger Intensity Interface Functions 8 Post Storage Master Menu 1 2 3 7 Persistence Recall Plot Trace Trace Save T ss ers Options Manipulation Arithmetic Limits Memory The Menus 3 Testing RR cm Re
81. s if no valid trigger has been received for 0 05s 1 e 20Hz 1s the lower limit CH1 CH2 Ext Line 1 7 Steps through trigger sources CH1 X 9 One of two channel signal input sockets this one being for the connection of signals up to 400Y peak to Channel It is used for the X component of an X Y mode trace It can also be a trigger source if selected using CHI CH2 Ext Line 2 12 As but CH2 is used for the Y component of an X Y trace where CHI is the X component CURSOR 7 These two buttons control the movement of the cursor Control 2 Selects the control master menu Dat Part of Dat Pos Mag 3 Allows the POST STOR AGE DATUM and CURSOR keys to be used to con trol the movement of the cursor and datum lines DC As part of AC DC GND DC couples the input signal directly to the instrument so that all frequency com ponents from DC to 20MHz are displayed As part of hf rej AC DC it couples triggers from DC to 20M Hz to the instrument 400 Series Operators Manual Ext External trigger source connected via EXT TRIG socket EXT TRIG Socket 1 6 for the connection of external triggers of up to 250Y peak Gnd Part of AC DC Gnd Gnd disconnects the input signal from the instrument and displays a OV reference signal instead hf rej AC DC 1 8 Selects trigger coupling The hf high frequency reject option is a 15kHz low pass filter Any coupling may be used with any trigger source excep
82. s pressed while the instrument 15 in ROLL mode on timebase ranges slower than 20ms div with the traces not stored or either channel not held b If in ROLL mode on timebase ranges faster than 50ms div with continuous acquisitions and and then the timebase range is changed to be 50ms div or slower 400 Series Operators Manual 15 NO IN XY MODE 16 17 18 19 20 21 22 25 24 29 26 27 28 29 30 31 32 If X MAG is pressed when X Y mode NO X MAG WHEN LIMITS DISPLAYED If X MAG is pressed while display limits is on NO X MAG WITH LIMITS TESTING If X MAG is pressed while the instrument is in limits testing mode NO XY WHEN LIMITS DISPLAYED If XY is pressed while display limits is on NO XY WHEN CHANNELS ADDED If trying to select X Y mode when channel ADD 15 on NO XY WITH X MAG If trying to select X Y mode when 15 on NOT WHEN LIMITS DISPLAYED If persistence 1s turned on while display limits 15 on NOT WHEN PERSISTENCE ON If display limits is turned on while the instrument is in persistence mode PLOTTING PRESS PLOT AGAIN TO ABORT Appears whilst plot is in progress TRI CURSOR MEASUREMENTS OFF If all three cursor measurement options are set to off this message appears TRI INVALID DATA If the data is invalid for the measurement selected TRACE COPIED To confirm that a trace has been copied to the reference trace Note also tha
83. strument 1s powered from the mains Triggering is then from an internal pulse having a fixed phase relation to the mains voltage waveform To change this phase relationship use the trigger delay buttons See Section 2 1 6 hf rejjAC DC 18 Steps through the available trigger cou pling options hf rej is a 15kHz low pass filter high frequency reject All the couplings can be used with any source except Line with which the input coupling is not selectable 400 Series Operators Manual Table 2 1 1 Useful Frequency Ranges of Coupling Types Coupling Input hfrej 10Hz to 15kHz AC 4Hz to 20M Hz DC DCt020MHz 2 1 2 Level The trigger level 15 the threshold at which the instrument will respond to potential triggers the trace actually has to pass through the level indicated for a trigger to be valid See Section 2 1 3 The level is indicated on the display by two bars one on each side of the screen and is adjusted by the level buttons 22 For an internal trigger the range 15 approximately 10 divisions and on external approximately 3V If the trigger signal is AC coupled the level bars will be offset from the actual trigger position on the screen by any DC offset present 2 1 3 Trigger Point T The trigger point is indicated on the display by a near the bottom of the screen underneath the trigger An arrow next to the T indicates that the trigger point is off the screen 2 1 4 Slope A trigger is ge
84. t Line where the coupling is not selectable Part of Off On Inv this option is used to invert the display of a channel s trace i e to negate it so that it is displayed upside down Level 22 Adjusts the trigger level which is indicated by two trigger bars on the display Line Mains frequency triggers Input coupling may not be selected with this option Mag 3 2 Used to control the horizontal magnification of the traces when selected a xl0 expansion around the centre of the screen is applied to the traces The timebase setting is altered to reflect the expansion Mag part of Dat Pos Mag 3 this allows the vertical mag nitude of a stored waveform to be varied using the POST STORAGE DATUM keys Menu Traces 3 5 Swaps the display between the last used menu and the trace display Mode 3 1 Selects one of three display modes Refreshed mode is the normal oscilloscope mode whereby the trace is plotted from left to right Roll mode is like a chart recorder the display scrolls from right to left as the trace is acquired X Y mode takes the X input as the x horizontal component and the CH2 Y input as the y vertical component Norm Part of Auto Norm The instrument will only initiate captures when a valid trigger is received when in Norm mode ns 3 3 Decreases the horizontal TIME DIV Off On Inv 1 3 Switches the channel On or Off If the channel 15 on its trace can be displayed Inverted upside dow
85. t if a trace is copied to the reference trace the reference trace is automatically turned on as well TRACE MEMORY UNUSED a If trying to turn the reference trace on when it has not been previously copied saved b If an attempt is made to recall a backup memory when that memory has not been previously saved TRACE NOT YET STORED If the cursor is selected and a post storage key pressed but the trace is not stored or held TRACE RECALLED To confirm that a trace has been recalled TRACE SAVED To confirm that a trace has been saved USE CH1 POS N KEYS IN XY If either horizontal position key is pressed when in X Y mode WAITING FOR TRIGGER If S SHOT has been selected but no trigger has been detected within 2s 400 Series Operators Manual Appendix 1 Error Messages 33 RESTORED WHEN STORED HELD 34 O IILS TO IOOILS DIV NO MAX MIN If the traces are stored or held in ROLL mode Then if If max min 1 selected when timebase 1 faster than X MAG is selected and either S SHOT or RUN is 100us DIV pressed or either channel unheld 1 6 X Mag has been turned off while the display is in active roll mode but it will be restored when the display is once again stored or held Appendix 2 Specification Appendix 2 Specification DISPLAY CRT 5 inch diagonal screen Raster scan vertically scanned Graticule Electronically generated 8 x 10 divisions with 0 2 sub divisions Intensity Separate controls for Traces Graticule
86. ted above The duty cycle is the ratio of the mark or space at the time datum to whole pulse period expressed as a percentage 1 Frequency Sco Period Ve ve lt Duty Cycle Figure 5 1 7 Freq Period Duty Cycle Measurement 5 1 8 RMS This selection calculates and displays both the RMS voltage with respect to the voltage datum and the 5 voltage with respect to the mean of the trace Both voltages are cal culated on the waveform bounded by the cursor and time datum Waveform Processing 5 1 9 5 2 4 5 1 9 Area This selection calculates the area bounded by the trace and the cursor and datum lines Figure 5 1 9 Area Measurement The result is given in volt seconds or similar units If the trace falls below the voltage datum then the area will be negative Positive and negative areas are added algebraically to obtain the displayed result 400 Series Operators Manual 5 2 Trace Manipulation Pressing button 5 on the Post Storage Master Menu changes the display to the Trace Manipulation Menu figure 5 2 The trace to be manipulated is selected with the cursor and the required function with button 2 3 or 5 If no trace has the cursor on it when button 2 3 or 5 is pressed the warning message NO TRACE SELECTED will be displayed Trace manipulations are with respect to the voltage datum line After any trace manipulation has been performed pressing button 7 labelled Restore will
87. the points alone will be displayed Selecting On causes the data to be automatically joined by straight lines 3 4 4 Averaging It is possible to improve the signal to noise ratio of repetitive signals by averaging them This function which converts the display into a weighted average of previous acquisitions is toggled On and Off by button 5 Button 6 is used to determine the averaging factor to be used in the algorithm a f 1 d A Where n data point 1 to 501 A New value at n an Old value atn f averaging factor 2 to 256 d Latest value atn e g continuous mode if 8 acquisitions are selected any single acquisition that deviates from an otherwise consistent level contributes 1 8 of its deviation to the display In S Shot only the selected number of acquisitions contribute to the resultant held display 3 4 5 Trig Pos n This displays the current value of either the pretrigger percentage or the post trigger delay time The value can be altered as described in section 2 1 6 Figure 2 1 6 shows the display relative to the trigger position for both pre and delay trigger values 400 Series Operators Manual 3 5 Display Intensity This menu allows independent control over the brightness of various display features TRACES CURSOR The brightness of the cursor datum lines and all traces will be adjusted The number key increases the intensity and the number 2 key decreases it Menu Trac
88. uccessfully set the message LIMIT SET is displayed Limit traces may be sent to or read from the 400 with an external computer using the mnemonics STU for the upper limit and STL for the lower limit using the data transfer facility described in section 2 6 The band between the upper and lower limits will be cross hatched and the limits testing will be performed on all the data points of both the upper and lower limit traces within the area bounded by the cursor and time datum lines Limit testing may be turned On or Off or set to Stop on fail by pressing button 3 When turned On each successive acquisition is tested and a warning message displayed when a trace is outside the limits This warning and trace will be overwritten by the next acquisition If the limits mode is set to Stop on fail acquisitions are halted when a trace that is outside the limits is captured 400 Series Operators Manual allowing it to be examined This screen picture can be plotted and with the internal colour plotter the upper and lower limits will be in the same colour as the reference trace to distinguish them from the failed trace During limits testing the trigger level and position markers are not displayed Test Limits and Display Limits cannot be turned on if the DSO is in X Y mode or if X Mag is turned on Similarly XMag or X Y mode cannot be selected if either Test Limits or Display Limits is on If any of these situations occur one of t
89. used as the X 8 bit resolution 25 steps div and CH2 as the Y 7 bit resolution 15 levels div deflection Single trace or 2 Dual trace and 2 400 Series Operators Manual Add CH1 and CH2 can be added to give the algebraic sum of the two channels Addition is post storage Invert Both channels may be independently inverted Single Shot Freezes store at the end of a single triggered sweep Display trace hold all Freezes the display immediately Channel 1 Trace hold Freezes channel display immediately Channel 2 Trace hold Freezes channel 2 display immediately Reference trace One reference trace can be displayed in addition to the two input channels This can display a waveform memory of a trace copied from or CH2 ACQUISITION SYSTEM Maximum sample rate 100 megasamples sec simultane ously on each channel Vertical resolution 8 Bits 1 256 30 levels per division Record length 501 points per channel ACQUISITION MODES Normal mode Transient and repetitive signal capture Repetitive capture is only on timebase ranges 100 or 200ns div which gives an equivalent sample rate of 2ns sample on the 100ns div range X Y Mode Bandwidth 20MHz 3dB 50MHz on 450 Phase difference lt 4 20MHz Acquisition rate dependent on the timebase range Averaging Averages can be set from 2 to 256 in binary sequence selected from the menu system Averaging operates continuously or using sin
90. y the sensitivity continuously See Section 1 6 3 Figure 1 6 Vertical Controls 1 6 2 Position Pos n 5 These move their respective traces up and down the display If Trace Hold is on Section 2 2 or a S Shot capture has been made any part of the trace which was captured off screen vertically will be shown by a horizontal line 1 6 3 Variable Uncalibrated Var 15 When this is set to Uncal the coarse setting of the attenuator remains unchanged but a variable attenuation is applied to the input signal in the range of 1 to 004 Thus with an initial setting of IV the actual sensitivity of the channel could be set by this control to anywhere between I V and 2 5V per division The V DIV buttons are used to vary the uncalibrated sensitivity Example screen display 25V Channel is set to a sensitivity of 5 Volts per screen division CH2 gt 20mV Channel 2 is uncalibrated and the attenuator is set to a sensitivity greater than 20m V per screen division 400 Series Operators Manual 1 6 4 Add Add 10 Displays the sum or if one channel is inverted the difference of the input signals The original traces disappear and the resultant trace is displayed as a Channel 2 trace 1 7 Manually Obtaining a Trace This subsection describes how to obtain a trace without using AUTO SETUP You may need to consult later sections of the manual as not all of the operating features have been discussed so far I When swit

Digital Storage Oscilloscopes Operators Manual Gould 400 Series

Contents

Download Pdf Manuals

Related Search

Related Contents