Home

TG4001 Instruction Manual - English - Iss 3

1. SWPSTOPFRQ lt nrf gt SWPSYNC lt cpd gt SWPTIME lt nrf gt SWPTYPE lt cpd gt SYNCOUT lt cpd gt TONEEND lt nrf gt TONEFREQ lt nrf1 gt lt nrf2 gt lt nrf3 gt 66 Set the arbitrary sample clock period to lt nrf gt sec Set the dc offset to lt nrf gt Volts Query and clear execution error number register Set the output filter to lt AUTO gt lt ELIP gt lt BESS gt or lt NONE gt Force a trigger to the selected channel Returns the instrument to local operation and unlocks the keyboard Will not function if LLO is in force Install data for a previous LRN command Set the modulation source to lt OFF gt or lt EXT gt Set the mode to lt CONTs gt lt GATE gt lt TRIG gt lt SWEEP gt or lt TONE gt Set the modulation type to lt AM gt or lt SCM gt Set the main output lt ON gt lt OFF gt lt NORMAL gt or lt INVERT gt Set the slave generator phase to lt nrf gt degrees Set the pulse delay to lt nrf gt sec Set the pulse period to lt nrf gt sec Set the pulse width to lt nrf gt sec Set the pulse train base line to lt nrf gt Volts Set the delay of pulse train pulse number lt nrf1 gt to lt nrf2 gt sec Set the number of pulses in the pulse train to lt nrf gt Set the level of pulse train pulse number lt nrf1 gt to lt nrf2 gt Volts Makes the pulse train and runs it similar to the WAVE PULSTRN command Set the pulse train period to lt nrf gt
2. THURLBY THANDAR INSTRUMENTS TG4001 40MHz DDS FUNCTION ARBITRARY GENERATOR INSTRUCTION MANUAL Introduction Specification Safety EMC Installation Connections Front Panel Connections Rear Panel Connections General Initial Operation Principles of Editing Principles of Operation Function Generator Operation Setting Generator Parameters Warnings and Error Messages SYNC Output Sweep Operation General Setting Sweep Parameters Triggered Burst and Gate General Triggered Burst Gated Mode Sync Out in Triggered Burst and Gated Mode Tone Mode Arbitrary Waveform Generation Introduction Selecting and Outputting Arbitrary Waveforms Frequency and Amplitude Control with Arbitrary Waveforms Sync Out Settings with Arbitrary Waveforms Output Filter Setting Pulse and Pulse trains Pulse Set up Pulse train Setup Modulation Table of Contents 11 12 14 14 15 17 17 18 19 21 21 23 24 26 26 26 30 30 31 32 33 34 36 36 36 37 37 37 39 39 40 43 Sum Synchronising Two Generators System Operations from the Utility Menu Calibration Equipment Required Calibration Procedure Calibration Routine Remote Calibration Remote Operation Power on Settings Remote Commands Frequency and Period Amplitude and DC Offset Waveform Selection Arbitrary Waveform Define Arbitrary Waveform Interrogation Mode Commands Input Output control Modulation Commands Synchronising Commands Status Commands Miscellaneous Commands Rem
3. 5mV Adjust for OV 5mV Adjust for 10V 10mV Adjust for 1V 1mV Adjust for 0 1V 1mV Adjust for 2 236V AC 10mV CAL 13 CH1 Not used CAL 14 CH1 Not used CAL 15 CH1 Not used CAL 16 Level 0 1 MHz Note reading CAL 17 Level 33MHz Check reading CAL 18 Level 1MHz Adjust for same reading CAL 19 Level 2MHz Adjust for same reading CAL 20 Level 4MHz Adjust for same reading CAL 21 Level 5MHz Adjust for same reading CAL 22 Level 10MHz Adjust for same reading CAL 23 Level 15MHz Adjust for same reading CAL 24 Level 20MHz Adjust for same reading 50 CAL 25 Level 25MHz Adjust for same reading CAL 26 Level 30MHz Adjust for same reading CAL 27 Level 32 5MHz Adjust for same reading CAL 28 Level 35MHz Adjust for same reading CAL 29 Level 37 5MHz Adjust for same reading CAL 30 Level 40MHz Adjust for same reading CAL 31 Clock calibrate Adjust for 10 00000 MHz at SYNC OUT Remote Calibration Calibration of the instrument may be performed over the RS232 or GPIB interface To completely automate the process the multimeter and frequency meter will also need to be remote controlled and the controller will need to run a calibration program unique to this instrument The remote calibration commands allow a simplified version of manual calibration to be performed by issuing commands from the controller The controller must send the CALADJ command repeatedly and read the dmm or frequency meter until the required result for the selected cali
4. Alternatively with the src selected double headed arrow the rotary control or cursor keys can be used to step backwards and forwards through the choices The source selection of the SYNC OUT waveform can be made automatic auto or user defined manual with alternate presses of the mode _ soft key In automatic mode the SYNC OUT waveform most appropriate for the current main waveform is selected For example waveform sync is automatically selected for all continuous waveforms but trigger is selected in trigger or gated waveform modes The automatic selection will be mentioned in each of the appropriate main waveform mode sections and a full table is given in Appendix 2 The automatic selection can still be changed manually by the src _ soft key even when auto mode has been selected but the selection will immediately revert to the automatic choice as soon as any relevant parameter e g main waveform frequency or amplitude is adjusted Manual must be selected by the mode soft key for a source other than the automatic choice to remain set The auto selection will generally set the most frequently used signal e g waveform sync for all continuous main waveforms but manual will need to be used for special requirements 25 Sweep Operation General Principles of Sweep Operation All standard and arbitrary waveforms can be swept with the exception of pulse and pulse train During Sweep all waveforms are generated in DDS mode because
5. Instead of using a counter to generate sequential RAM addresses a phase accumulator is used to increment the phase 44 Bit 12 Bit 20 Bit RAM ADDRESS 8 Top Bits PHASE 44 Bit CLOCK sets to 0000 INCREMENT REGISTER PHASE ACCUMULATOR On each clock cycle the phase increment which has been loaded into the phase increment register by the CPU is added to the current result in the phase accumulator the 12 most significant bits of the phase accumulator drive the lower 12 RAM address lines the upper 4 RAM address lines are held low The output waveform frequency is now determined by the size of the phase increment at each clock If each increment is the same size then the output frequency is constant if it changes the output frequency changes as in sweep mode The generator uses a 44 bit accumulator and a 100 MHz clock frequency the frequency setting resolution is 0 1 mHz Only the 12 most significant bits of the phase accumulator are used to address the RAM Ata waveform frequency of FcLk 4096 24 4kHz the natural frequency the RAM address increments at every clock At all frequencies below this i e at smaller phase increments one or more addresses are output for more than one clock period because the phase increment is not big enough to step the address at every clock Similarly at frequencies above the natural frequency the larger phase increment causes some addresses to be skipped giving the effect of the stored waveform
6. User s external filter defines bandwidth and response OPERATING MODES Triggered Burst Each active edge of the trigger signal will produce one burst of the waveform Carrier Waveforms Maximum Carrier Frequency Number of Cycles Trigger Repetition Rate Trigger Signal Source Trigger Start Stop Phase All standard and arbitrary The smaller of 2 5MHz or the maximum for the selected waveform 100Msamples s for ARB 1 to 1 048 575 0 005Hz to 100kHz internal dc to 1MHz external Internal from keyboard or trigger generator External from TRIG IN or remote interface 360 settable with 0 1 resolution subject to waveform frequency and type Gated Waveform will run while the Gate signal is true and stop while false Carrier Waveforms Maximum Carrier Frequency Trigger Repetition Rate Gate Signal Source Gate Start Stop Phase Sweep All standard and arbitrary The smaller of 2 5MHz or the maximum for the selected waveform 100Msamples s for ARB 0 005Hz to 100kHZz internal dc to 1MHz external Internal from keyboard or trigger generator External from TRIG IN or remote interface 360 settable with 0 1 resolution subject to waveform frequency and type Frequency sweep capability is provided for both standard and arbitrary waveforms Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to perform the sweep Carrier Waveforms Sweep Mode
7. 10 EC Declaration of Conformity We Thurlby Thandar Instruments Lid Glebe Road Huntingdon Cambridgeshire PE29 7DR England declare that the TG4001 40MHz DDS Function Arbitrary Generator meets the intent of the EMC Directive 2004 108 EC and the Low Voltage Directive 2006 95 EC Compliance was demonstrated by conformance to the following specifications which have been listed in the Official Journal of the European Communities EMC Emissions a EN61326 1998 Radiated Class A b EN61326 1998 Conducted Class B c EN61326 1998 Harmonics referring to EN61000 3 2 2000 Immunity EN61326 1998 Immunity Table 1 Performance B referring to a EN61000 4 2 1995 Electrostatic Discharge EN61000 4 3 1997 Electromagnetic Field EN61000 4 11 1994 Voltage Interrupt EN61000 4 4 1995 Fast Transient EN61000 4 5 1995 Surge EN61000 4 6 1996 Conducted RF a o o gt Oo Safety EN61010 1 2001 Installation Category II Pollution Degree 2 Cki tarp CHRIS WILDING TECHNICAL DIRECTOR 1 February 2007 EMC This instrument has been designed to meet the requirements of the EMC Directive 2004 108 EC Compliance was demonstrated by meeting the test limits of the following standards Emissions EN61326 1998 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test limits used were a Radiated Class A b Conducted Class B c Harmonics EN61000 3 2 2000 Clas
8. Amplitude AMPLITUDE 20 0 Vpp Vpp Vrms 0 dBm load hiZ o Pressing the AMPL key gives the AMPLITUDE screen The waveform amplitude can be set in terms of peak to peak Volts Vpp r m s Volts Vrms or dBm referenced to a 50Q or 6009 load For Vpp and Vrms the level can be set assuming that the output is open circuit Load hiZ or terminated load 50Q or load 6002 when dBm is selected termination is always assumed and the load hiZ __ setting is automatically changed to load 50Q Note that the actual generator output impedance is always 50Q the displayed amplitude values for 600Q termination take this into account With the appropriate form of the amplitude selected indicated by the filled diamond the amplitude can be entered directly from the keyboard in integer floating point exponential or direct units format e g 250mV can be entered as 250 or 250 exp 3 etc However the display will always show the entry in the most appropriate engineering units in this case 250mV Turning the rotary control will increment or decrement the numeric value in steps determined by the position of the edit cursor flashing underline the cursor is moved with the left and right arrowed cursor keys Alternate presses of the key will invert the MAIN OUT output if DC OFFSET is non zero the signal is inverted about the same offset The exception to this is if the amplitude is specified in dBm since low level signals are specified in d
9. If sync is setto off the output operates exactly as described above if sync is setto on the frequency actual goes to zero at the start and begins each new sweep at the first point of the waveform For triggered sweeps a trigger signal may be provided by any of the possible trigger sources i e internal external manual or remote The generator does not provide a ramp output for use with X Y displays or recorders Sweep Spacing Pressing the spacing soft key onthe SWEEP SETUP screen calls the SWEEP SPACING screen SWEEP SPACING logarithmic Olinear With linear selected the sweep changes the frequency at a linear rate with Logarithmic selected the sweep spends an equal time in each frequency decade 28 Sweep Marker A sweep marker pulse is also available from the SYNC OUT socket when sweep sync the default condition is selected The marker pulse is differentiated from the sweep sync pulse by being approximately half the amplitude of the sync pulse this permits the trigger level of the display oscilloscope to be adjusted for the sweep sync pulse without additionally triggering on the marker pulse The marker pulse frequency is set from the SWEEP MARKER FREQ menu called by pressing the marker soft key onthe SWEEP SETUP screen SWEEP MARKER FREQ progrm 5 000 MHz actual 4 977 MHz done gt Anew marker frequency can be programmed directly from the keyboard or by using the rotary control and cursor keys
10. NEW PASSWORD STORED for two seconds and then revert to the UTILITY menu If any keys other than 0 9 are pressed while entering the password the message ILLEGAL PASSWORD will be shown Using the Password to Access Calibration or Change the Password With the password set pressing calibration onthe UTILITY screen will now show ENTER PASSWORD 49 When the correct password has been entered from the keyboard the display changes to the opening screen of the calibration routine and calibration can proceed as described in the Calibration Routine section If an incorrect password is entered the message INCORRECT PASSWORD is shown for two seconds before the display reverts to the UTILITY menu With the opening screen of the calibration routine displayed after correctly entering the password the password can be changed by pressing password soft key and following the procedure described in Setting the Password If the password is set to 0000 again password protection is removed The password is held in EEPROM and will not be lost when the memory battery back up is lost In the event of the password being forgotten contact the manufacturer for help in resetting the instrument Calibration Routine The calibration procedure proper is entered by pressing continue on the opening Calibration screen pressing exit returns the display tothe UTILITY menu Pressing tests calls a menu of basic hardware checks used at production test these ar
11. No internal connection 2 TXD Transmitted data from instrument 3 RXD Received data to instrument 4 No internal connection 5 GND Signal ground 6 No internal connection 7 RXD2 Secondary received data addressable RS232 only 8 TXD2 Secondary transmitted data addressable RS232 only 9 GND Signal ground addressable RS232 only Single Instrument RS232 Connections For single instrument remote control only pins 2 3 and 5 are connected to the PC However for correct operation links must be made in the connector at the PC end between pins 1 4 and 6 and between pins 7 and 8 see diagram Pins 7 and 8 of the instrument must not be connected to the PC i e do not use a fully wired 9 way cable PC 9 WAY D INSTRUMENT 9WAYD FEMALE MALE DCD i 1 O1 RX 2 2 a RX TX 3 3 m TX DTR 4 O4 GND 5C 5 GND DSR 6C O6 RTS 7 07 CTS ai 8 O8 LINKS TO Ri 90 NULL OUT PC O9 Baud Rate is set as described above in Address and Baud Rate Selection the other parameters are fixed as follows Start Bits 1 Parity None Data Bits 8 Stop Bits 1 Addressable RS232 Connections For addressable RS232 operation pins 7 8 and 9 of the instrument connector are also used Using a simple cable assembly a daisy chain connection system between any number of instruments up to the maximum of 32 can be made as shown below CONTROLLER INSTRUMENT INSTRUMENT INSTRUMENT 4 2 3 TO_NEXT ss INSTRUME
12. Note that the marker frequency can only be one of the values in the sweep frequency table any value in the sweep range can be entered but the actual value will be the nearest frequency in the table When sweep is turned on the actual marker frequency is shown in the non editable field below the programmed frequency For the default sweep setting of 100kHz to 10MHz in 50ms the actual frequency of a 5MHz marker is 4 998 MHz The marker duration is Sweep time 2000 i e the dwell time at a single frequency step To avoid displaying a sweep marker the marker frequency is simply set to a value outside the current sweep frequency range 29 Triggered Burst and Gate General Triggered Burst and Gated modes are selected from the MODE screen called by the MODE key as alternatives to the default continuous mode MODE continuous gated setup otriggered setup In Triggered Burst mode a defined number of cycles are generated following each trigger event This mode is edge triggered In gated mode the generator runs whenever the gating signal is true This mode is level sensitive Triggered Burst mode can be controlled by either the Internal Trigger Generator an external trigger input by the front panel MAN TRIG key or by remote control Gated mode can be controlled by the Internal Trigger Generator or on external trigger input In both modes the start phase i e the starting point on the waveform cycle can be specified
13. ODH Carriage Return CR formatting code otherwise ignored 11H Restart transmission XON 12H Listen Address must be followed by an address belonging to the required instrument 13H Stop transmission XOFF 14H Talk Address must be followed by an address belonging to the required instrument 18H Universal Device Clear 55 USB Interface The USB interface allows the instrument to be controlled via a PC s USB port The instrument is supplied with a CD containing drivers for various versions of Windows including Win98 and 2000 Any driver updates are available via the TTi website www tti test com The CD also contains a pdf file with information and details of the software installation procedure Installation of the driver is achieved by connecting the instrument to a PC via a standard USB cable The Windows plug and play functions should automatically recognise the addition of new hardware attached to the USB interface and if this is the first time the connection has been made prompt for the location of a suitable driver Provided that the standard Windows prompts are followed correctly Windows will install the appropriate driver The driver will remain installed on the PC and should be called automatically each time the instrument is connected to the PC via USB in the future The waveform design software supplied with this generator has been enhanced to permit downloads to the instrument using USB For users wishing to wri
14. Pressing the FREQuency key with an arbitrary waveform selected calls the ARB FREQUENCY screen ARB FREQUENCY 1000 00000 MHz sample waveform freq periodo Arbitrary mode uses Clock Synthesis generation see Principles of Operation section which has a setting resolution of 8 digits Frequency can be set in terms of frequency or period as for standard waveforms by pressing the freq or period soft key respectively Additionally for arbitrary waveforms frequency period can be set in terms of the sample clock frequency by pressing the sample soft key or in terms of the waveform frequency by pressing the waveform soft key The relationship between them is waveform frequency sample frequency waveform size Frequency period entries are made direct from the keyboard or by using the rotary control in the usual way Amplitude Pressing the AMPLitude key with an arbitrary waveform selected calls the AMPLITUDE screen AMPLITUDE 20 0 Vpp Vpp load hiZ0 This differs from the AMPLITUDE screen for standard waveforms in that amplitude can now only be entered in volts peak to peak Note that the peak to peak amplitude set will only actually be output if the arbitrary waveform has addresses with values which reach 2048 and 2047 if the maximum value range is 1024 to 1023 for example then the maximum peak to peak voltage will only be 10Vpp for the instrument set to 20Vpp Sync Out Settings with Arbitrary Waveforms The defau
15. Refer to the System Operations section for how to change the power up settings to either those at power down or to any one of the stored settings Recall the status screen at any time with the STATUS key a second press returns the display to the previous screen Change the basic generator parameters as described in the Standard Waveform Operation section and switch the output on with the MAIN OUT key the ON lamp will light to show that the output is on Display Contrast All parameter settings are displayed on the 20 character x 4 row backlit liquid crystal display LCD The contrast may vary a little with changes of ambient temperature or viewing angle but can be optimised for a particular environment by using the front panel contrast control Insert a small screwdriver or trimmer tool through the adjustment aperture marked LCD and rotate the control for optimum contrast Keyboard Pressing the front panel keys displays screens which list parameters or choices relative to the key pressed Selections are then made using the display soft keys and numeric values are changed using the numeric keys or rotary control see the Principles of Editing section The keys are grouped as follows e FUNCTION FREQuency AMPLitude OFFSET and MODE keys display screens which permit their respective parameters to be edited either from the numeric keypad or using the rotary control cursor keys e Numeric keys permit direct entry of a value for the parameter
16. Sweep Direction Sweep Range Sweep Time Marker Sweep Trigger Source Tone Switching All standard and arbitrary except pulse and pulse train Linear or logarithmic triggered or continuous Up down up down or down up From 1mHz to 40MHz in one range Phase continuous Independent setting of the start and stop frequency 1ms to 999s 3 digit resolution Variable during sweep The sweep may be free run or triggered from the following sources Manually from keyboard Externally from TRIG IN input or remote interface Capability provided for both standard and arbitrary waveforms Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to allow instantaneous frequency switching Carrier Waveforms Frequency List Trigger Repetition Rate Source Tone Switching Modes All waveforms except pulse and pulse train Up to 16 frequencies from 1mHz to 40MHz 0 005Hz to 100kHZz internal dc to 1MHz external Usable repetition rate and waveform frequency depend on the tone switching mode Internal from keyboard or trigger generator External from TRIG IN or remote interface Gated The tone is output while the trigger signal is true and stopped at the end of the current waveform cycle while the trigger signal is false The next tone is output when the trigger signal is true again Triggered The tone is output when the trigger signal goes true and the next tone is output at the
17. an error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 1 to be placed in the Query Error Register and the response formatter to be reset thus clearing the output queue The parser will then start parsing the next lt PROGRAM MESSAGE UNIT gt from the input queue See the Status Reporting section for further information The IEEE 488 2 DEADLOCK error is handled as follows If the response formatter is waiting to send a response message and the input queue becomes full then the instrument enters the DEADLOCK state and an error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 2 to be placed in the Query Error Register and the response formatter to be reset thus clearing the output queue The parser will then start parsing the next lt PROGRAM MESSAGE UNIT gt from the input queue See the Status Reporting section for further information GPIB Parallel Poll Complete parallel poll capabilities are offered on this generator The Parallel Poll Enable Register is set to specify which bits in the Status Byte Register are to be used to form the ist local message The Parallel Poll Enable Register is set by the PRE lt nrf gt command and read by the PRE command The value in the Parallel Poll Enable Register is ANDed with the Status Byte Register if the result is zero then the value of ist is 0 otherwise the value of ist is 1 The ins
18. being sampled different points will be sampled on successive cycles of the waveform Function Generator Operation This section deals with the use of the instrument as a function generator i e generating sine square triangle dc ramp haversine cosine havercosine and sinx x waveforms All but squarewave are generated by DDS which gives 10 digit frequency resolution squarewave is generated by Clock Synthesis which results in 8 digit frequency resolution Refer to Principles of Operation in the previous section for a fuller explanation of the differences involved The WAVEFORM FUNCTIONS screen lists all the waveforms that the instrument can produce including pulse pulse train and arbitrary which are described in detail in their appropriate sections Much of the following descriptions of amplitude and offset control as well as of Mode Sweep etc in following sections apply to arbitrary waveforms as well as standard function generator waveforms for clarity any differences of operation with arbitrary pulse and pulse train are described only in those sections Setting Generator Parameters Waveform Selection WAVEFORM FUNCTIONS sine square triangle Pressing the FUNCTION key gives the WAVEFORM FUNCTIONS screen which lists all the waveforms available the rotary control or cursor keys can be used to scroll the full list back and forward through the display The currently selected waveform sine with the factory defaults
19. frequencies For DDS operation all waveforms must be 4096 points in length this is the natural length for standard waveforms but all arbitrary waveforms are expanded or condensed in software to 4096 points when the Tone list is built This does not affect the original data Because DDS mode is used the frequency range for all waveforms is 1mHz to 10MHz in Tone mode including triangle ramp and squarewave which have different limits in continuous operation Tone Frequency Press the tone setup soft key on the MODE screen called by pressing the MODE key to getthe TONE setup screen TONE type trig 02 000000 kHz 2 3 000000 kHz delo Yend of list 4 Each frequency in the list can be changed by pressing the appropriate soft key and entering the new value from the keyboard The selected frequency can be deleted from the list by pressing the del delete soft key Additional frequencies can be added to the end of the list by selecting end of list withthe appropriate soft key and entering the new frequency from the keyboard The whole list can be scrolled back and forward through the display using the rotary control Tone Type 34 The type soft key onthe TONE setup screen permits three types of tone switching to be specified With type setto trig the frequency changes after each occurrence of the signal edge specified inthe source and slope fields onthe TRIGGER IN screen but only after completing the last cycle of the current fr
20. i e it does not dwell at the stop frequency for the full step interval and then starts the next sweep from the first point of the waveform synchronised to the internally generated trigger signal This is useful because the sweep always starts from the same point in the waveform but the waveform discontinuity can be undesirable in some circumstances e g filter evaluation With sync setto off the frequency steps directly and phase continuously from the stop frequency to the start frequency after dwelling at the Stop frequency for the full step interval but is not synchronised to the software generated trigger signal In triggered mode the generator holds the output at the start frequency until it recognises a trigger When triggered the frequency sweeps to the stop frequency resets as follows and awaits the next trigger If sync if set to on the frequency resets to zero frequency i e no waveform and starts a new sweep at the first point of the waveform when the next trigger is recognised If syne is setto off the waveform resets to the start frequency and runs at that frequency until the next trigger initiates a new sweep In trig d hold reset mode the generator holds the output at the start frequency until it recognises a trigger when triggered the frequency sweeps to the stop frequency and holds At the next trigger the output is reset to the start frequency where it is held until the next sweep is initiated by a further trigger
21. is edge sensitive the selected edge of each external trigger initiates the specified burst In Gated mode the input is level sensitive the output of the main generator is on whilst the gate signal is true The minimum pulse width that can be used with TRIG IN in Triggered Burst and Gated mode is 50ns and the maximum repetition rate is 1MHz The maximum signal level that can be applied without damage is 10V When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to trigger which is always a positive edged version of the external trigger or gate signal when external triggering or gating is specified Triggered Burst Triggered Burst mode is turned on withthe triggered soft key on the MODE screen The setup soft key on this screen accesses the TRIGGER GATE SETUP screen on which the burst count and start phase are set The other trigger parameters are set on the TRIGGER IN setup screen called by pressing the TRIG IN key source int force slope positive level 1 4 V period 1 00ms Trigger Source The trigger source can be selected with the source soft key on the TRIGGER IN setup screen tobe int ext or man With int selected the internal trigger generator is used to initiate a burst this generator is set up as described in the previous section With ext selected the specified edge of the signal at TRIG IN is used to initiate a burst With man selected as the source only pressing the MAN TRIG ke
22. length The values are separated by a comma character and the data ends with lt pmi gt Define an arbitrary waveform with name lt cpd gt and length lt nrf gt and load with the data in lt bin data block gt The name must be one of ARB1 ARB2 ARB3 or ARB4 The data will overwrite that currently stored for the specified arbitrary waveform and the waveform will be given the new length The data consists of two bytes per point with no characters between bytes or points The point data is sent high byte first The data block has a header which consists of the character followed by several ascii coded numeric characters The first if these defines the number of ascii characters to follow and these following characters define the length of the binary data in bytes Due to the binary data block this command cannot be used over the RS232 interface Arbitrary Waveform Interrogation ARBDATACSV lt cpd gt ARBDATA lt cpd gt ARBLEN lt cpd gt Mode Commands MODE lt cpd gt BSTCNT lt nrf gt PHASE lt nrf gt TONEEND lt nrf gt TONEFREQ lt nrf1 gt lt nrf2 gt lt nri3 gt SWPSTARTFRQ lt nrf gt SWPSTOPFRQ lt nrf gt SWPCENTFRQ lt nrf gt SWPSPAN lt nrf gt SWPTIME lt nrf gt 62 Returns the data from an existing arbitrary waveform lt cpd gt must be one of ARB1 ARB2 ARB3 or ARB4 The data consists of ascii coded values as specified for the ARBDEFCSV command Returns the data from an existing arbitrary
23. message This setup can be changed on the error menu error beep ON error message ON warn beep ON warn message ON Each feature can be turned ON or OFF with alternate presses of the appropriate soft key The last two error messages can be viewed by pressing the last error soft key Each message has a number and the full list appears in Appendix 1 See also Warnings and Error Messages in the Standard Waveform Operation section Remote Interface Setup Pressing remote calls the REMOTE setup screen which permits RS232 GPIB USB choice and selection of address and Baud rate Full details are given in the Remote Operation section Reference Clock In Out Setting The function of the rear panel REF CLOCK IN OUT socket is set on the REF CLOCK screen called by pressing the ref clock soft key 47 REF CLOCK ref clk input The default setting is for the socket to be set to input i e an input for an external 10MHz reference clock When set to input the system is automatically switched over to the external reference when an adequate signal level TTL CMOS threshold is detected at REF CLOCK IN OUT but will continue to run from the internal clock in the absence of such a signal With the clock set to output a buffered version of the internal 10MHz clock is made available at the socket Select master or slave when used for synchronising phase locking multiple generators See Synchronising Generators section f
24. period 107 Pulse width cannot be less than 10ns 108 Maximum output level exceeded 109 Minimum output level exceeded 110 Minimum dc offset value exceeded 111 Maximum dc offset value exceeded 112 The value entered is out of range 119 Arb waveform length cannot be less than four points 125 No GPIB available 127 System ram error battery fault or firmware updated 135 Trigger generator maximum period is 200s 136 Trigger generator minimum period is 10us 137 Waveform is not available with ext clock 138 Burst count value exceeds the maximum of 1048575 139 Burst count value cannot be less than 1 140 Trig Gate freq too high Max 2 5MHz Continuous mode set 141 Selected function is illegal in tone mode TONE MODE CANCELLED 144 Selected combination of function and mode is illegal 145 Locked master slave is available with continuous mode only 69 148 Trig gate mode and seq step value cause a trigger conflict 150 Number of pulses in train must be between 1 and 10 151 Pulse train base level must be gt 5 0V and lt 5 0V 152 Pulse level must be gt 5 0V and lt 5 0V 153 Pulse number must be between 1 and 10 154 Sweep frequency values must be 1mHz to 40MHz 155 Sweep start freq must be less than stop freq 156 Sweep stop freq must be greater than start freq 157 Sweep time value is out of range 0 001s lt n lt 999s 158 Sweep marker value is out of range 0 001Hz lt n lt 40MHz 160 Notlocked This error indicates that a phas
25. program delay The delay value that can be entered must be in the range pulse period 1 point positive values delay the pulse output with respect to waveform sync from SYNC OUT negative values cause the pulse to be output before the waveform sync Pressing the done soft key on this screen returns the display to the WAVEFORM FUNCTIONS screen The means by which pulse period is set up in the hardware requires an understanding because it affects the setting resolution of both pulse width and delay Pulse is actually a particular form of arbitrary waveform made up of between 4 and 100 000 points each point has a minimum time of 10 00ns corresponding to the fastest clock frequency of 100MHz 39 At short pulse periods i e only a few points in the waveform the period setting resolution is however much better than 10 00ns because the time per point is adjusted as well as the number of points since the pulse width and delay are also defined in terms of the same point time varying the time per point affects their resolution For example if the period is set to 200ns the minimum pulse width when set to 10 00ns will actually be 10 00ns 20 points at 10 00ns each exactly define the 200ns period However if the period is set to 199 Ons 20 points at the minimum point time of 10 00ns will be too long so 19 points are used and the point time is adjusted to 10 473684ns 199 0 19 10 473684ns is now the increment size used when changing
26. repair Any adjustment maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and if inevitable shall be carried out only by a skilled person who is aware of the hazard involved If the instrument is clearly defective has been subject to mechanical damage excessive moisture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair Make sure that only fuses with the required rated current and of the specified type are used for replacement The use of makeshift fuses and the short circuiting of fuse holders is prohibited This instrument uses a Lithium button cell for non volatile memory battery back up typical life is 5 years In the event of replacement becoming necessary replace only with a cell of the correct type i e 3V Li MnO 20mm button cell type 2032 Exhausted cells must be disposed of carefully in accordance with local regulations do not cut open incinerate expose to temperatures above 60 C or attempt to recharge Do not wet the instrument when cleaning it and in particular use only a soft dry cloth to clean the LCD window The following symbols are used on the instrument and in this manual Caution refer to the accompanying documentation incorrect operation may damage the instrument terminal connected to chassis ground mains supply OFF mains supply ON oHe alternating current
27. sec Set the width of pulse train pulse number lt nrf1 gt to lt nrf2 gt sec Query and clear query error number register Set the ref clock bnc to lt IN gt lt OUT gt lt MASTER gt or lt SLAVE gt Set the sum source to lt OFF gt or lt EXT gt Set the sweep centre frequency to lt nrf gt Hz Set the sweep direction to lt UP gt lt DOWN gt lt DNUP gt or lt UPDN gt Set the sweep marker to lt nrf gt Hz Set the sweep spacing to lt LIN gt or lt LOG gt Set the sweep frequency span to lt nrf gt Hz Set the sweep start frequency to lt nrf gt Hz Set the sweep stop frequency to lt nrf gt Hz Set the sweep sync lt ON gt or lt OFF gt Set the sweep time to lt nrf gt sec Set the sweep type to lt CONT gt lt TRIG gt or lt THLDRST gt Set the sync output lt ON gt lt OFF gt lt AUTO gt lt WFMSYNCs lt POSNMKR3 gt lt BSTDONE gt lt SEQSYNC gt lt TRIGGER3 gt lt SWPSYNC gt or lt PHASLOC gt Delete tone frequency number lt nrf gt thus defining the end of the list Set tone frequency number lt nrf1 gt to lt nrf2 gt Hz The third parameter sets the tone type 1 will give Trig 2 will give FSK any other value gives Gate type TRIGIN lt cpd gt TRIGLEV lt nrf gt TRIGPER lt nrf gt USBID WAVE lt cpd gt WAVFREQ lt nrf gt WAVPER lt nrf gt WFMCLKSRC lt cpd gt ZLOAD lt cpd gt Set the trig input to lt INT gt lt EXT gt lt MAN gt lt PR
28. setting is indicated by the filled diamond the selection is changed by pressing the soft key beside the required waveform Frequency SINE FREQUENCY 10 00000000 kHz freq periodo Pressing the FREQ key gives the SINE FREQUENCY screen With freq selected as shown above the frequency can be entered directly from the keyboard in integer floating point exponential or direct units format e g 12 34 kHz can be entered as 12340 12340 00 1 234 exp 4 or 12 34 kHz etc However the display will always show the entry in the most appropriate engineering units in this case 12 34000000 kHz With period selected instead of freq the frequency can be set in terms of a period e g 123 4us can be entered as 0001234 or 123 4e 6 again the display will always show the entry in the most appropriate engineering units Squarewave generated by Clock Synthesis has 8 digit resolution for both frequency and period entry but the editing method is the same as for DDS generated waveforms Turning the rotary control will increment or decrement the numeric value in steps determined by the position of the edit cursor flashing underline the cursor is moved with the left and right arrowed cursor keys Note that the upper frequency limits vary for the different waveform types refer to the Specifications section for details Frequency setting for arbitrary pulse and pulse train is explained in the relevant sections all use Clock Synthesis mode 21
29. the cursor in the most significant digit the rotary control will decrement the offset in 100mV steps as follows program 205 mVdc program 105 mVdc program 5 00 mVdc program 95 0 mVdc program 195 mVdc The actual DC offset at the MAIN OUT socket is attenuated by the fixed step output attenuator when this is in use Since it is not obvious when the signal is being attenuated the actual offset is shown in brackets as a non editable field below the programmed value For example if the amplitude is set to 2 5Vpp the output is not attenuated by the fixed attenuator and the actual DC offset in brackets is the same as that set The DC OFFSET display shows DC OFFSET program 1 50 Vdc actual 1 50 Vdc load hizo If the amplitude is now reduced to 250mVpp which introduces the attenuator the actual DC offset changes by the appropriate factor DC OFFSET program 1 50 Vdc actual 151 mVdc load hizo The above display shows that the set DC offset is 1 50V but the actual offset is 151mV Note that the actual offset value also takes into account the true attenuation provided by the fixed attenuator using the values determined during the calibration procedure In the example displayed the output signal is 250mVpp exactly and takes account of the small error in the fixed attenuator the offset is 151 mV exactly taking account of the effect of the known attenuation slightly less than the nominal on the
30. this offers the significant advantage of phase continuous sweeps over a very wide frequency range up to 10 However it must be remembered that the frequency is actually stepped not truly linearly swept and thought needs to be given as to what the instrument is actually doing when using extreme combinations of sweep range and time For DDS operation during Sweep all waveforms must be 4096 points in length this is the natural length for standard waveforms but all arbitrary waveforms are expanded or condensed in software to 4096 points when Sweep is turned on This does not affect the original data Sweep mode is turned on and off either by the on or off soft key onthe SWEEP SETUP screen accessed by pressing the SWEEP front panel key or by the sweep soft key on the MODE screen When sweep is turned on the software creates a table of 2000 frequencies between and including the specified start and stop values Because any frequency used in sweep mode must be one of the tabled values the centre frequency displayed see Sweep Range may not be the exact mid point and markers see Sweep Marker may not be exactly at the programmed frequency The frequency resolution of the steps will be particularly coarse with wide sweeps Connections for Sweep Operation Sync Out and Trig In Sweeps are generally used with an oscilloscope or hard copy device to investigate the frequency response of a circuit The MAIN OUT is connected to the circuit input a
31. use on the addressable RS232 bus use the following set of interface control codes Codes between 00H and 1FH which are not listed here as having a particular meaning are reserved for future use and will be ignored Mixing interface control codes inside instrument commands is not allowed except as stated below for CR and LF codes and XON and XOFF codes When an instrument is first powered on it will automatically enter the Non Addressable mode In this mode the instrument is not addressable and will not respond to any address commands This allows the instrument to function as a normal RS232 controllable device This mode may be locked by sending the Lock Non Addressable mode control code 04H The controller and instrument can now freely use all 8 bit codes and binary blocks but all interface control codes are ignored To return to addressable mode the instrument must be powered off To enable addressable mode after an instrument has been powered on the Set Addressable Mode control code 02H must be sent This will then enable all instruments connected to the addressable RS232 bus to respond to all interface control codes To return to Non Addressable mode the Lock Non Addressable mode control code must be sent which will disable addressable mode until the instruments are powered off Before an instrument is sent a command it must be addressed to listen by sending the Listen Address control code 12H followed by a single character which has th
32. year Since the ageing rate decreases exponentially with time it is an advantage to recalibrate after the first 6 month s use Apart from this it is unlikely that any other parameters will need adjustment Calibration should be carried out only after the generator has been operating for at least 30 minutes in normal ambient conditions Equipment Required e 3 digit DVM with 0 25 DC accuracy and 0 5 AC accuracy at 1kHz e Frequency counter capable of measuring 10 O0000MHz The DVM is connected to the MAIN OUT and the counter to the SYNC OUT Frequency meter accuracy will determine the accuracy of the generator s clock setting and should ideally be 1ppm Calibration Procedure The calibration procedure is accessed by pressing the calibration soft key onthe UTILITY screen CALIBRATION SELECTED Are you sure password tests dexit continue The software provides for a 4 digit password in the range 0000 to 9999 to be used to access the calibration procedure If the password is left at the factory default of 0000 no messages are shown and calibration can proceed as described in the Calibration Routine section only if a non zero password has been set will the user be prompted to enter the password Setting the Password On opening the Calibration screen press the password soft key to show the password screen ENTER NEW PASSWORD Enter a 4 digit password from the keyboard the display will show the message
33. 00kHz Clock Synthesised waveforms lt 300ns lt 1 to 10kHz Synchronising Having made the connections and set up the generators as described in the preceding paragraphs synchronisation is achieved by pressing the MAN TRIG key of the slave Once synchronised any change to the setup will require resynchronisation with the MAN TRIG key again Other Phase Locking Considerations 46 The following further points should also be considered The waveform filters introduce a frequency dependent delay above 1MHz this will affect the accuracy of the phase between locked waveforms at different frequencies e g 500KHz and 5MHz Square waves which are 2 point Clock Synthesised waveforms will not reliably lock to other Clock Synthesised waveforms Pulse and Pulse train waveforms will lock to other Pulse and Pulse trains and each other but should be built with equal periods Arb waveforms should be the same length although this is not forced and does not create an error message To avoid excessive locking times when using DDS waveforms the actual frequency is offset by a small amount lt 1ppm to ensure that no frequency is an exact sub multiple of the 100MHz clock frequency This in turn ensures that the master instrument will always produce the required locking signal from the SYNC OUT socket This frequency offset is applied in three ranges 0 to 25kHz 25kHz to 1MHz and 1MHz to 40MHz It is not possible to lock frequencies fro
34. 32 and USB interfaces as standard which can be used for remote control of all of the instrument functions or for the down loading of arbitrary waveforms As well as operating in conventional RS232 mode the serial interface can also be used in addressable mode whereby up to 32 instruments can be linked to a single PC serial port There is also a GPIB option Specification Specifications apply at 18 28 C after 30 minutes warm up at maximum output into 50Q WAVEFORMS Standard Waveforms Sine square triangle DC positive ramp negative ramp sin x x pulse pulse train cosine haversine havercosine and 4 user defined Arbitrary waveforms Sine Cosine Haversine Havercosine Range Resolution Accuracy Temperature Stability Output Level Harmonic Distortion Non harmonic Spurii Square Range Resolution Accuracy Output Level Rise and Fall Times Triangle Range Resolution Accuracy Output Level Linearity Error Ramps and Sin x x Range Resolution Accuracy Output Level Linearity Error 0 1mHz to 40MHz 0 1mHz or 10 digits 10 ppm for 1 year Typically lt 1 ppm C 2 5mV to 10Vp p into 50Q lt 0 15 THD to 100kHz lt 60dBc to 20kHz lt 50dBc to 1MHz lt 40dBc to 10MHz lt 30dBc to 40MHz lt 60dBc to 1MHz lt 60dBc 6dB octave 1MHz to 40MHz 1mHz to 50MHz 1mHz 8 digits 10 ppm for 1 year 2 5mV to 10Vp p into 50Q lt 8ns 0 1mHz to 500kHz 0 1m
35. Bm OdBm 1mW into 509 224mVrms the sign is interpreted as part of a new amplitude entry and not as a command to invert the signal Note that for DC sinx x pulse pulse train and arbitrary amplitude can only be displayed and entered in the Vpp form further limitations on pulse pulse train and arbitrary amplitude are discussed in the appropriate sections DC Offset 22 DC OFFSET program 0 00 mVdc actual 0 00 mVdc load hiZ9 Pressing the OFFSET key gives the DC OFFSET screen The offset can be entered directly from the keyboard in integer floating point exponential or direct units format e g 100mV can be entered as 1 or 100 exp 3 etc However the display will always show the entry in the most appropriate engineering units in this case 100mV During a new offset entry the key can be used at any time to set the offset negative alternate presses toggle the sign between and Turning the rotary control will increment or decrement the numeric value in steps determined by the position of the edit cursor flashing underline the cursor is moved by the left and right arrowed cursor keys Because DC offset can have negative values the rotary control can take the value below zero although the display may autorange to a higher resolution if a step takes the value close to zero the increment size is maintained correctly as the offset is stepped negative For example if the display shows program 205 mVdc with
36. EV gt lt NEXT gt lt POS gt or lt NEG gt Set the trigger threshold level to lt nrf gt Volts Set the internal trigger generator period to lt nrf gt sec Returns the instruments address Select the output waveform as lt SINE gt lt SQUAREs gt lt TRIANGs gt lt DC gt lt POSRMP3 gt lt NEGRMP3 gt lt COSINE gt lt HAVSIN gt lt HAVCOSs gt lt SINC gt lt PULSE gt lt PULSTRN gt lt NOISE gt lt ARB1 gt lt ARB2 gt lt ARB3 gt or lt ARB4 gt Set the waveform frequency to lt nrf gt Hz Set the waveform period to lt nrf gt sec Set the playback clock source of the selected waveform to lt INT gt or lt EXT gt Set the output load which the generator is to assume for amplitude and dc offset entries to lt 50 gt 509 lt 600 gt 600Q or lt OPEN gt 67 Maintenance The Manufacturers or their agents overseas will provide a repair service for any unit developing a fault Where owners wish to undertake their own maintenance work this should only be done by skilled personnel in conjunction with the service manual which may be purchased directly from the Manufacturers or their agents overseas Cleaning If the instrument requires cleaning use a cloth that is only lightly dampened with water or a mild detergent WARNING TO AVOID ELECTRIC SHOCK OR DAMAGE TO THE INSTRUMENT NEVER ALLOW WATER TO GET INSIDE THE CASE TO AVOID DAMAGE TO THE CASE NEVER CLEAN WITH SOLVENTS 68 A
37. GISTER SRE lt NRF gt SET TO lt NRF gt SRE READ Status Model Power on Settings The following instrument status values are set at power on Status Byte Register 0 Service Request Enable Register t 0 Standard Event Status Register 128 pon bit set Standard Event Status Enable Register t 0 Execution Error Register 0 Query Error Register 0 Parallel Poll Enable Register t 0 t Registers marked thus are specific to the GPIB section of the instrument and are of limited use in an RS232 environment The instrument will be in local state with the keyboard active The instrument parameters at power on are determined on the POWER ON SETTING screen accessed from the UTILITY menu If restore last setup or recall store no nn has been set and a defined state is required by the controller at start up then the command RST should be used to load the system defaults If for any reason an error is detected at power up in the non volatile ram a warning will be issued and all settings will be returned to their default states as for a RST command 59 Remote Commands RS232 Remote Command Formats Serial input to the instrument is buffered in a 256 byte input queue which is filled under interrupt in a manner transparent to all other instrument operations The instrument will send XOFF when approximately 200 characters are in the queue XON will be sent when approximately 100 free spaces become available in the queue after
38. Hz or 10 digits 10 ppm for 1 year 2 5mV to 10Vp p into 509 lt 0 1 to 30 kHz 0 1mHz to 500kHz 0 1mHz 10 digits 10 ppm for 1 year 2 5mV to 10Vp p into 50Q lt 0 1 to 30 kHz Pulse and Pulse Train Output Level Rise and Fall Times Period Range Resolution Accuracy Delay Range Resolution Width Range Resolution 2 5mV to 10Vp p into 509 lt 8ns 40ns to 100s 8 digit 10 ppm for 1 year 99 99s to 99 99s 0 001 of period or 10ns whichever is greater 10ns to 99 99s 0 001 of period or 10ns whichever is greater Note that the pulse width and absolute value of the delay may not exceed the pulse period at any time Pulse trains of up to 10 pulses may be specified each pulse having independently defined width delay and level The baseline voltage is separately defined and the sequence repetition rate is set by the pulse train period Arbitrary Up to 4 user defined waveforms may be stored in non volatile memory Waveforms can be defined by downloading of waveform data via RS232 GPIB or USB Waveform Memory Size Vertical Resolution Sample Clock Range Resolution Accuracy Output Filter 4 waveforms maximum waveform size is 65536 points minimum waveform size is 4 points 12 bits 100mHz to 100MHz 8 digits 10 ppm for 1 year Selectable between 40MHz Elliptic 20MHz Bessel or none Noise Digital noise generated by a 35 bit linear feedback register clocked at 100MHz
39. Internal Trigger Generator The period of the Internal Trigger Generator is set with the period soft key onthe TRIGGER IN set up screen called by the TRIG IN key source int force slope positive Olevel 1 4 V period 1 00ms The Internal Trigger Generator divides down a crystal oscillator to produce a 1 1 square wave with a period from 0 01ms 100kHz to 200s 005Hz Generator period entries that cannot be exactly set are accepted and rounded up to the nearest available value e g 109ms is rounded to 11ms When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to trigger which is the output of the internal trigger generator when internal triggering or gating is specified In Triggered Burst mode the selected edge of each cycle of the trigger generator is used to initiate a burst the interval between bursts is therefore 0 01ms to 200s as set by the generator period In Gated mode the output of the main generator is gated on whilst the Internal Trigger Generator output is true the duration of the gate is therefore 005ms to 100s in step with trigger generator periods of 01ms to 200s External Trigger Input 30 External trigger or gate signals are applied to the front panel TRIG IN socket which has a variable threshold level set using the level soft key the level can be set from 5 0V to 5 0V by direct keyboard entry or by using the rotary control In Triggered Burst mode the input
40. LDRST gt Set the sweep direction to lt UP gt lt DOWN gt lt UPDN gt or lt DNUP gt Set the sweep sync lt ON gt or lt OFF gt Set the sweep spacing to lt LIN gt or lt LOG gt Set the sweep marker to lt nrf gt Hz Set the main output lt ON gt lt OFF gt lt NORMAL gt or lt INVERT gt Set the sync output lt ON gt lt OFF gt lt AUTO gt lt WFMSYNC gt lt POSNMKR3 gt lt BSTDONE gt lt SEQSYNC gt lt TRIGGER3 gt lt SWPSYNC gt or lt PHASLOC3 gt Set the trig input to lt INT gt lt EXT gt lt MAN gt lt PREV gt lt NEXT gt lt POS gt or lt NEG gt Set the trigger threshold level to lt nrf gt Volts Set the internal trigger generator period to lt nrf gt sec Force a trigger to the selected channel Will function with any trigger source except MANUAL specified Set the modulation source to lt OFF gt or lt EXT gt Set the modulation type to lt AM gt or lt SCM gt Set the sum source to lt OFF gt or lt EXT gt Synchronising Commands REFCLK lt cpd gt ABORT PHASE lt nrf gt Status Commands CLS ESE lt nrf gt ESE ESR DN ST OPC Set the ref clock bnc to lt IN gt lt OUT gt lt MASTER gt or lt SLAVE gt Aborts an external phase synchronising operation Set the generator phase to lt nrf gt degrees This parameter is used for setting the trigger gate mode start stop phase and the phase difference when synchronising inst
41. NE gt lt SQUAREs gt lt TRIANG gt lt DC gt lt POSRMP3 gt lt NEGRMP3 gt lt COSINE gt lt HAVSIN gt lt HAVCOSs gt lt SINC gt lt PULSE gt lt PULSTRN gt lt NOISE gt lt ARB1 gt lt ARB2 gt lt ARB3 gt or lt ARB4 gt Set the pulse period to lt nrf gt sec Set the pulse width to lt nrf gt sec Set the pulse delay to lt nrf gt sec Set the number of pulses in the pulse train to lt nrf gt 61 PULTRNPER lt nrf gt PULTRNBASE lt nrf gt PULTRNLEV lt nrf1 gt lt nrf2 gt PULTRNWID lt nrf1 gt lt nrf2 gt PULTRNDLY lt nrf1 gt lt nrf2 gt PULTRNMAKE Set the pulse train period to lt nrf gt sec Set the pulse train base line to lt nrf gt Volts Set the level of pulse train pulse number lt nrf1 gt to lt nrf2 gt Volts Set the width of pulse train pulse number lt nrf1 gt to lt nrf2 gt sec Set the delay of pulse train pulse number lt nrf1 gt to lt nrf2 gt sec Makes the pulse train and runs it similar to the WAVE PULSTRN command Arbitrary Waveform Define ARBDEFCSV lt cpd gt lt nrf gt lt csv ascii data gt ARBDEF lt cpd gt lt nrf gt lt bin data block gt Define an arbitrary waveform with name lt cpd gt and length lt nrf gt and load with the data in lt csv ascii data gt The name must be one of ARB1 ARB2 ARB3 or ARB4 The data will overwrite that currently stored for the specified arbitrary waveform and the waveform will be given the new
42. NT The daisy chain consists of the transmit data TXD receive date RXD and signal ground lines only There are no control handshake lines This makes XON XOFF protocol essential and allows the inter connection between instruments to contain just 3 wires The wiring of the adaptor cable is shown below 53 9 WAY D 9 WAY D FEMALE MALE DCD 4 O1 RX a 2 O2 a TX TX 30 3 me RX DTR m 4 O4 GND 5 5 GND DSR wi 6 O6 RTS t 7 O7 CTS 8 Os RI i 90 O9 LINKS TO CONTROLLER M ou ec CHAIN S lt OO 9 WAY D me 123456789 ME AN INSTRUMENT 1 ON THE CHAIN TX RX TXIN RXOUT All instruments on the interface must be set to the same baud rate and all must be powered on otherwise instruments further down the daisy chain will not receive any data or commands The other parameters are fixed as follows Start Bits 1 Parity None Data Bits 8 Stop Bits 1 RS232 Character Set Because of the need for XON XOFF handshake it is possible to send ASCII coded data only binary blocks are not allowed Bit 7 of ASCII codes is ignored i e assumed to be low No distinction is made between upper and lower case characters in command mnemonics and they may be freely mixed The ASCII codes below 20H space are reserved for addressable RS232 interface control In this manual 20H etc means 20 in hexadecimal Addressable RS232 Interface Control Codes 54 All instruments intended for
43. Only one response message will be sent each time the instrument is addressed to talk Talk mode will be cancelled by any of the following interface control codes being received 12H Listen Address for any instrument 14H Talk Address followed by an address not belonging to this instrument 03H Universal Unaddress control code 04H Lock Non Addressable mode control code 18H Universal Device Clear Talk mode will also be cancelled when the instrument has completed sending a response message or has nothing to say The interface code OAH LF is the universal command and response terminator it must be the last code sent in all commands and will be the last code sent in all responses The interface code ODH CR may be used as required to aid the formatting of commands it will be ignored by all instruments Most instruments will terminate responses with CR followed by LF The interface code 13H XOFF may be sent at any time by a listener instrument or controller to suspend the output of a talker The listener must send 11H XON before the talker will resume sending This is the only form of handshake control supported by the addressable RS232 mode Full List of Addressable RS232 Interface Control Codes 02H Set Addressable Mode 03H Universal Unaddress control code 04H Lock Non Addressable mode control code O6H Acknowledge that listen address received OAH Line Feed LF used as the universal command and response terminator
44. Q CLOCK OUT will withstand a short circuit As an input the threshold is TTL CMOS compatible Do not apply external voltages exceeding 5V or 1V to this signal connection Do not apply an external voltage exceeding 5V or 1V MAIN OUT This plugged panel position is provided for the user to fit a 50Q BNC as an alternative to the front panel MAIN OUT socket where rear panel connections are required in a rack mounted system The front panel MAIN OUT connection must be carefully disconnected from the pcb and the pcb then rewired using high quality 50Q coax to the new rear panel connector Do not apply an external voltage to this output RS232 9 pin D connector compatible with addressable RS232 use The pin connections are shown below Pin Name Description 1 No internal Connection 2 TXD Transmitted data from instrument 3 RXD Received data to instrument 4 No internal connection 5 GND Signal ground 6 No internal connection 7 RXD2 Secondary received data 8 TXD2 Secondary transmitted data 9 GND Signal ground Pin 2 3 and 5 may be used as a conventional RS232 interface with XON XOFF handshaking Pins 7 8 and 9 are additionally used when the instrument is used in addressable RS232 mode Signal grounds are connected to instrument ground The RS232 address is set from the remote menu onthe UTILITY screen see System Operations section 15 GPIB IEEE 488 OPTIONAL USB 16 The GPIB interface is not isolated the GPIB sign
45. RITICAL STOP Stack Underflow firmware error 207 CRITICAL STOP Illegal instruction firmware error 208 CRITICAL STOP Illegal NMI firmware error 209 CRITICAL STOP Heap overflow firmware error Appendix 2 SYNC OUT Automatic Settings The following automatic source sre settings are made when auto mode is selected on the SYNC OUT screen Waveform Burst Sweep Phase WAVEFORM Sync Done Trigger Trigger Lock Continuous al GateTrig au Ew d S O sweep a CC f fone J A Pv 71 Appendix 3 Factory System Defaults The factory system defaults are listed in full below They can be recalled by pressing RECALL followed by set defaults orby the remote command RST All channels will be receive the same setup All channels default to the same settings Main Parameters Std Wave Sine Frequency 10kHz Output 2 0Vpp Output Off DC Offset OV Zout HiZ Gate Trigger Parameters Source Internal Period ms Slope Positive Burst Count 1 Phase Odeg Modulation Parameters Source Off Type VCA Sum Off Sweep Parameters Begin Frequency 100kHz End Frequency 40MHz Marker Frequency 10MHz Direction Up Spacing Log Sweep Time 10ms Type Continuous Filter Auto Sync Out Auto Arbitrary All unaffected by reset or RST 72 Appendix 4 Waveform Manager Plus Arbitrary Waveform Creation and Management Software The Thurloy Thandar Waveform Manager Plus program allows construction editin
46. SAGE TERMINATOR gt A lt RESPONSE MESSAGE TERMINATOR is the new line character with the END message NL END Each query produces a specific lt RESPONSE MESSAGE gt which is listed along with the command in the remote commands list lt WHITE SPACE gt is ignored except in command identifiers e g C LS is not equivalent to CLS lt WHITE SPACE gt is defined as character codes OOH to 20H inclusive with the exception of the NL character OAH The high bit of all characters is ignored The commands are case insensitive Command List This section lists all commands and queries implemented in this instrument The commands are listed in alphabetical order within the function groups Note that there are no dependent parameters coupled parameters overlapping commands expression program data elements or compound command program headers each command is completely executed before the next command is started All commands are sequential and the operation complete message is generated immediately after execution in all cases The following nomenclature is used lt rmt gt lt RESPONSE MESSAGE TERMINATOR gt lt cpd gt lt CHARACTER PROGRAM DATA gt i e a short mnemonic or string such as ON or OFF lt nrf gt A number in any format e g 12 12 00 1 2 e 1 and 120 e 1 are all accepted as the number 12 Any number when received is converted to the required precision consistent with the use then rounded up to obtain the value o
47. XOFF was sent This queue contains raw un parsed data which is taken by the parser as required Commands and queries are executed in order and the parser will not start a new command until any previous command or query is complete In non addressable RS232 mode responses to commands or queries are sent immediately there is no output queue In addressable mode the response formatter will wait indefinitely if necessary until the instrument is addressed to talk and the complete response message has been sent before the parser is allowed to start the next command in the input queue Commands must be sent as specified in the commands list and must be terminated with the command terminator code OAH Line Feed LF Commands may be sent in groups with individual commands separated from each other by the code 3BH The group must be terminated with command terminator OAH Line Feed LF Responses from the instrument to the controller are sent as specified in the commands list Each response is terminated by ODH Carriage Return CR followed by OAH Line Feed LF lt WHITE SPACE gt is defined as character codes OOH to 20H inclusive with the exception of those which are specified as addressable RS232 control codes lt WHITE SPACE gt is ignored except in command identifiers e g C LS is not equivalent to CLS The high bit of all characters is ignored The commands are case insensitive GPIB Remote Command Formats 60 GPIB in
48. a master and TRIG IN on a slave to synchronise phase lock two separate generators 5V 1V Full remote control facilities are available through the RS232 USB or GPIB interfaces RS232 IEEE 488 USB GENERAL Display Data Entry Stored Settings Size Weight Power Operating Range Storage Range Environmental Options Safety EMC Variable Baud rate 38400 Baud maximum 9 pin D connector Optional Conforms with IEEE488 1 and IEEE488 2 1 1 20 character x 4 row alphanumeric LCD Keyboard selection of mode waveform etc value entry direct by numeric keys or by rotary control Up to 9 complete instrument set ups may be stored and recalled from non volatile memory 3U 130mm height 212mm Y2 rack width 335mm long 4 1kg 9lb 220 240V nominal 50 60Hz 110 120V or 100V nominal 50 60 400Hz nominal voltage adjustable internally operating range 10 of nominal 60VA max Installation Category II 5 C to 40 C 20 80 RH 20 C to 60 C Indoor use at altitudes up to 2000m Pollution Degree 2 19 inch rack mounting kit GPIB remote control interface Complies with EN61010 1 Complies with EN61326 Safety This generator is a Safety Class instrument according to IEC classification and has been designed to meet the requirements of EN61010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use It is an Installation Category II instrument inte
49. able Register will cause the ESB bit to be set in the Status Byte Register The Standard Event Status Register is read and cleared by the ESR command The Standard Event Status Enable register is set by the ESE lt nrf gt command and read by the ESE command Bit 7 Power On Set when power is first applied to the instrument Bit 6 Not used Bit 5 Command Error Set when a syntax type error is detected in a command from the bus The parser is reset and parsing continues at the next byte in the input stream 57 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Execution Error Set when an error is encountered while attempting to execute a completely parsed command The appropriate error number will be reported in the Execution Error Register Not used Query Error Set when a query error occurs The appropriate error number will be reported in the Query Error Register as listed below 1 Interrupted error 2 Deadlock error 3 Unterminated error Not used Operation Complete Set in response to the OPC command Status Byte Register and Service Request Enable Register 58 These two registers are implemented as required by the IEEE std 488 2 Any bits set in the Status Byte Register which correspond to bits set in the Service Request Enable Register will cause the RQS MSS bit to be set in the Status Byte Register thus generating a Service Request on the bus The Status Byte Register is read eithe
50. al grounds are connected to the instrument ground The implemented subsets are SH1 AH1 T6 TEO L4 LEO SR1 RL1 PP1 DC1 DT1 CO E2 The GPIB address is set from the remote menu onthe UTILITY screen see System Operations section The USB port is connected to instrument ground It accepts a standard USB cable If USB has been selected as the current interface the Windows plug and play function should automatically recognise that the instrument has been connected General Initial Operation This section is a general introduction to the organisation of the instrument and is intended to be read before using the generator for the first time Detailed operation is covered in later sections starting with Standard Waveform Operation In this manual front panel keys and sockets are shown in capitals e g OFFSET SYNC OUT all softkey labels entry fields and messages displayed on the LCD are shown in a different type font e g WAVEFORM FUNCTIONS sine Switching On The power switch is located at the bottom left of the front panel At power up the generator displays the installed software revision whilst loading its waveform RAM if an error is encountered the message system ram error battery fault or firmware updated will be displayed see the Warnings and Error Messages section Loading takes a few seconds after which the status screen is displayed showing the generator parameters set to their default values with the MAIN OUT output set off
51. ary waveforms is limited by the waveform length since the maximum resolution is 1 clock thus waveforms with a length gt 3600 points will have a resolution of 0 1 but below this number of points the maximum resolution becomes 360 number of points Square waves pulse and pulse trains have no start phase adjustment phase is fixed at 0 Refer to the table in the Triggered Burst section for a summary of start phase capabilities Sync Out in Triggered Burst and Gated Mode When Triggered Burst or Gated modes are selected the SYNC OUT source automatically defaults to trigger trigger is a positive edged signal synchronised to the actual trigger used whether internal from the Internal Trigger Generator or external of either polarity Alternatively SYNC OUT can be setto burst done onthe SYNC OUT setup screen sync out then provides a signal which is low while the waveform is running and high at all other times 33 Tone Mode General In Tone mode the output is stepped through a user defined list of up to 16 frequencies under the control of the signal set by the source soft key onthe TRIGGER IN setup screen This signal can be the Internal Trigger Generator an external trigger input the front panel MAN TRIG key or a remote command All standard and arbitrary waveforms can be used in Tone mode with the exception of pulse and pulse train During Tone all waveforms are generated in DDS mode for fast phase continuous switching between
52. beep ON Owarn message ON Each feature can be turned ON and OFF with alternate presses of the associated soft key the factory default is for all features to be ON SYNC Output 24 SYNC OUT is a multifunction CMOS TTL level output that can be automatically or manually set to be any of the following e waveform sync A square wave with 50 duty cycle at the main waveform frequency or a pulse coincident with the first few points of an arbitrary waveform Can be selected for all waveforms e burst done Produces a pulse coincident with the last cycle of the burst e trigger Selects the current trigger signal internal external or manual Useful for synchronising burst or gated signals e sweep sync Outputs the sweep trigger and sweep marker signals e phase lock Used to lock two or more generators Produces a positive edge at the 0 phase point The setting up of the signals themselves is discussed in the relevant sections later in this manual e g trigger is described in the Triggered Burst Gate section Pressing the SYNC OUT key calls the SYNC OUT setup screen SYNC OUT output on Omode auto a v src waveform sync SYNC OUT is turned on and off by alternate presses of the output soft key The selection of the signal to be output from the SYNC OUT socket is made using the sre source soft key repeated presses of src cycle the selection through all the choices waveform sync burst done etc listed above
53. bration step is achieved The CALSTEP command is then issued to accept the new value and move to the next step While in remote calibration mode very little error checking is performed and it is the controllers responsibility to ensure that everything progresses in an orderly way Only the following commands should be used during calibration WARNING Using any other commands while in calibration mode may give unpredictable results and could cause the instrument to lock up requiring the power to be cycled to regain control CALIBRATION lt cpd gt nrf The calibration control command lt cpd gt can be one of three sub commands START Enter calibration mode this command must be issued before any other calibration commands will be recognised SAVE Finish calibration save the new values and exit calibration mode ABORT Finish calibration do not save the new values and exit calibration mode lt nrf gt represents the calibration password The password is only required with CALIBRATION START and then only if a non zero password has been set from the instrument s keyboard The password will be ignored and will give no errors at all other times It is not possible to set or change the password using remote commands CALADJ lt nrf gt Adjust the selected calibration value by lt nrf gt The value must be in the range 100 to 100 Once an adjustment has been completed and the new value is as required the CALSTEP command must be i
54. by Clock Synthesis mode squarewave arbitrary pulse pulse train and sequence because of the relatively poor precision with which the frequency is actually derived in the hardware With these waveforms frequencies with an apparently rational relationship e g 3 1 may be individually synthesised such that the ratio is not close enough to e g 3 1 to maintain phase lock over a period of time the only relationships guaranteed to be realised precisely are 2 1 because the division stages in Clock Synthesis mode are binary A further complication arises with arb waveforms because waveform frequency depends on both waveform size and clock frequency waveform frequency clock frequency waveform size The important relationship with arbs is the ratio of clock frequencies and the above considerations on precision apply to them The most practical use of synchronisation will be to provide outputs at the same frequency or maybe harmonics but with phase differences Connections for Synchronisation The clock connection arrangement is for the rear panel REF CLOCK IN OUT of the master which will be set to master to be connected directly to the REF CLOCK IN OUT socket of the slave which will be set to slave Similarly the synchronising connection is from the SYNC OUT of the master which defaults to phase lock to the TRIG IN input of the slave Generator Set ups Each generator can have its main parameters set to any value with the exceptio
55. content Pulse and Pulse trains Pulse and pulse trains are both selected and set up from independent menus on the WAVEFORM FUNCTIONS screen called by pressing the FUNCTION key Pulse and pulse trains have similar timing set ups and considerations but pulses are only unipolar with a maximum amplitude of 10Vpp whereas pulse trains can be bipolar with a maximum peak to peak of 20Vpp Pulse Set up Pulse waveforms are turned on with the pulse soft key onthe WAVEFORM FUNCTIONS screen pressing the setup soft key beside pulse calls the first of the pulse set up screens Enter pulse period 100 00000 us 10000pts 10 000000ns exit next The pulse period can be set between 40 00ns and 100s with 8 digit resolution by direct entries from the keyboard or by using the rotary control Pressing the next soft key calls the pulse width screen Enter pulse width program 50 000000 us actual 50 000000 us exit next The width can be entered directly from the keyboard or by using the rotary control Any value in the range 10 00ns to 99 99s can be programmed but the actual value may differ because of the considerations discussed below for this reason the actual pulse width is shown below the program width Pressing the next soft key calls the pulse delay screen Enter pulse delay progrm 0 0000000 ns actual 0 0000000 ns exit done Q This is very similar to the pulse width screen and again the actual delay is shown below the
56. creen items are marked with a double headed arrow a split diamond when selected to indicate that the item s setting can be changed by further presses of the soft key by pressing either cursor key or by using the rotary control For example pressing FILTER brings up the screen shown below FILTER SETUP mode auto Otype 40MHz eliptic Repeated presses of the mode soft key will toggle the mode between its two possible settings of auto and manual Similarly when type is selected repeated presses of the type soft key or cursor keys or use of the rotary control will step the selection through all possible settings of the filter type In addition to their use in editing items identified by a double headed arrow as described above the CURSOR keys and ROTARY CONTROL operate in two other modes In screens with lists of items that can be selected i e items marked with a diamond the cursor keys and rotary control are used to scroll all items through the display if the list has more than three items look for example at the FUNCTION and UTILITY screens In screens where a parameter with a numeric value is displayed the cursor keys move the edit cursor a flashing underline through the numeric field and the rotary control will increment or decrement the value the step size is determined by the position of the edit cursor within the numeric field Thus for FREQUENCY set to 1 000000000 MHz rotating the control will change the freq
57. currently selected Values are accepted in four formats integer 20 floating point 20 0 exponential 2 EXP 1 and direct units selection 20Hz For example to set a new frequency of 50kHz press FREQ followed by 50000 ENTER or 5 EXP 4 ENTER or 50 kHz ENTER or an appropriate units key confirms the numeric entry and changes the generator setting to the new value CE Clear Entry undoes a numeric entry digit by digit ESCAPE returns a setting being edited to its last value e MODULATION SUM TRIG IN and SYNC OUT call screens from which the parameters of those input outputs can be set including whether the port is on or off e SWEEP similarly calls screens from which all the parameters can be set and the function run e The MAIN OUT key simply switches the main output on or off e MAN TRIG is used for manual triggering when TRIG IN is appropriately set and for synchronising two or more generators when suitably connected together 17 e UTILITY gives access to menus for a variety of functions such as remote control interface set up power up parameters error message settings and store recall waveforms to from non volatile memory e Eight soft keys around the display are used to directly set or select parameters from the currently displayed menu their operation is described in more detail in the next section e The STATUS key always returns the display to the default start up screen which gives an overview of the generators status Pres
58. d entry or by using the rotary control Sweep Type Pressing the type soft key calls the SWEEP TYPE screen SWEEP TYPE continuous direction up Osync on done This screen is used to set the sweep mode continuous triggered triggered hold and reset and sweep direction 27 Successive presses of the direction soft key select one of the following sweep directions up start frequency to stop frequency down stop frequency to start frequency up down start frequency to stop frequency and back to start frequency down up stop frequency to start frequency and back to stop frequency The total sweep time is always that seton the SWEEP TIME screen i e for up down and down up operation the sweep time in each direction is half the total Similarly the total number of steps is the same for all choices i e there will be half the number of steps in each direction for up down and down up operation In the sweep mode descriptions which follow the direction is assumed to be up but all modes can be used with all sweep directions In continuous mode the generator sweeps continuously between the start and stop frequencies triggered repetitively by an internal trigger generator whose frequency is determined by the sweep time setting At the stop frequency the generator resets to the start frequency and begins a new sweep If sync is setto on the default the generator actually steps immediately from the stop frequency to zero frequency
59. determined both by the arb clock and the total number of data points in the cycle In this instrument an arb waveform can have up to 65536 horizontal points The vertical range is 2048 to 2047 corresponding to a maximum peak peak output of 20 Volts Four waveforms can be specified and they are listed at the bottom of the WAVEFORM FUNCTIONS screen WAVEFORM FUNCTIONS Opulse train setup Yarb1 1000 points Yarb2 1000 points The four arbs have names arb1 arb2 arb3 and arb4 which cannot be changed As it is not possible to delete these arbs a new instrument has four default arbs installed each 1000 points long Each arb has its current length specifies on the WAVEFORM FUNCTIONS screen as shown above Arb waveforms can be created using the supplied waveform design software that enables the user to create waveforms from mathematical expressions from combinations of other waveforms or freehand on a pc see Appendix 4 These waveforms may then be downloaded to the instrument via one of the remote control interfaces Arb Waveform Terms The following terms are used in describing arb waveforms e Horizontal Size The number of horizontal points is the time component of the waveform The minimum size is 4 points and the maximum is 65536 points e Waveform Address Each horizontal point on an arb waveform has a unique address Addresses always start at 0000 thus the end address is always one less than the horizontal size e Arb Frequ
60. e frequency 50kHz maximum switching frequency 1MHz FSK Maximum tone frequency 1MHz maximum switching frequency 1MHz l l l l l GATE TRIG FSK TRIGGER WAVEFORM Tone Waveform Types Tone Switching Source The signal which controls the frequency switching is that set by the source soft key on the TRIGGER IN setup screen The slope field on the same screen sets the active polarity of that signal when setto positive the rising edge of the trigger signal is active or the high level of the gating signal is true and the reverse is true fora negative setting The signal that can be selected by the source _ soft key can be the Internal Trigger Generator an external trigger input the front panel MAN TRIG key or a remote command A full explanation for each of these can be found in the Triggered Burst and Gate chapter DTMF Testing with Two Generators An important use of Tone mode is DTMF Dual Tone Multiple Frequency testing in which 2 instruments are set up with equal length lists of different frequencies and are triggered from a common external signal The outputs are summed together using the external SUM capability see the Sum chapter DTMF testing generally uses sinewaves in the frequency range 600Hz to 1 6KHz 35 Arbitrary Waveform Generation Introduction Arbitrary Arb waveforms are generated by sequentially addressing the RAM containing the waveform data with the arbitrary clock The frequency of the arb waveform is
61. e frequency steps Produces a positive edge coincident with the start of the current waveform this is used for phase locking instruments This waveform may not appear coherent SYNC OUT logic levels are nominally OV and 5V from typically 509 SYNC OUT will withstand a short circuit Do not apply an external voltage to this output TRIG IN This is the external input for Trigger Gate Sweep and Sequence operations It is also the input used to synchronise the generator as a slave to another which is the master Do not apply an external voltage exceeding 10V 14 Rear Panel Connections MODULATION IN This is the input socket for external modulation Do not apply an external voltage exceeding 10V SUM IN This is the input socket for external signal summing Do not apply an external voltage exceeding 10V REF CLOCK IN OUT The function of the CLOCK IN OUT socket is set from the ref clock i o menu onthe UTILITY screen see System Operations section input This is the default setting The socket becomes an input for an external 10MHz reference clock The system automatically switches over from the internal clock when the external reference is applied output The internal 10MHz clock is made available at the socket phase lock When two or more generators are synchronised the slaves are set to phase lock slave andthe master is setto phase lock master As an output the logic levels are nominally 1V and 4V from typically 50
62. e largely self explanatory but details can be found in the Service Manual if required At each step the display changes to prompt the user to adjust the rotary control or cursor keys until the reading on the specified instrument is at the value given The cursor keys provide coarse adjustment and the rotary control fine adjustment Pressing next increments the procedure to the next step pressing CE decrements back to the previous step Alternatively pressing exit returns the display to the last CAL screen at which the user can choose to either save new values recall old values or calibrate again The first two displays CAL 00 and CAL 01 specify the connections and adjustment method The next display CAL 02 allows the starting channel to be chosen this allows quick access to any particular channel To calibrate the complete instrument choose the default setting of CH1 The subsequent displays CAL 03 to CAL 31 permit all adjustable parameters to be calibrated The full procedure is as follows CAL 03 CH1 CAL 04 CH1 CAL 05 CH1 CAL 06 CH1 CAL 07 CH1 CAL 08 CH1 CAL 09 CH1 CAL 10 CH1 CAL 11 CH1 CAL 12 CH1 DC offset zero DC offset at full scale DC offset at full scale Multiplier zero Multiplier offset Waveform offset Output level at full scale 20dB attenuator 40cB attenuator 10dB attenuator Adjust for OV 5mV Adjust for 10V 10mV Check for 10V 3 Adjust for minimum Volts AC Adjust for OV
63. e locking operation has failed 161 Illegal phase value 184 SUM or Modulation conflict 188 Maximum trigger level is 5 0V 189 Minimum trigger level is 5 0v Remote Warnings 72 Length is different to that in the ARBDEF CSV command Remote Errors Criti 70 120 Waveform limit value out of range 126 Illegal store number requested 162 Byte value outside the range 0 to 255 163 Specified arb name does not exist 164 Command illegal in sweep or tone mode 166 Cannot set sample frequency or period for std waveforms 167 dBm output units assume a 50 Ohm termination 168 Specified units illegal for the selected waveform 169 Command not available for RS232 170 Length value error in binary block 171 Illegal value in arbitrary data 173 Illegal tone number 177 Illegal remote calibration command 185 Command not available while sweeping cal Stop Errors These errors have no obvious recovery path and require user intervention Some can be bypassed by a key press some offer a choice of action Possible hardware failures may be firmware induced and recover by cycling the power Firmware errors all require a power cycle to recover Any of these errors may indicate an imminent system failure or a firmware bug 201 CRITICAL STOP Fault in clock circuit of channel lt chan gt possible hardware failure 202 CRITICAL STOP Fault in calibration flash memory block flash write fault 205 CRITICAL STOP Stack Overflow firmware error 206 C
64. e lower 5 bits corresponding to the unique address of the required instrument e g the codes A Z or a z give the addresses 1 26 inclusive while is address 0 and so on Once addressed to listen the instrument will read and act upon any commands sent until the listen mode is cancelled Because of the asynchronous nature of the interface it is necessary for the controller to be informed that an instrument has accepted the listen address sequence and is ready to receive commands The controller will therefore wait for Acknowledge code 06H before sending any commands The addressed instrument will provide this Acknowledge The controller should time out and try again if no Acknowledge is received within 5 seconds Listen mode will be cancelled by any of the following interface control codes being received 12H Listen Address followed by an address not belonging to this instrument 14H Talk Address for any instrument 03H Universal Unaddress control code 04H Lock Non Addressable mode control code 18H Universal Device Clear Before a response can be read from an instrument it must be addressed to talk by sending the Talk Address control code 14H followed by a single character which has the lower 5 bits corresponding to the unique address of the required instrument as for the listen address control code above Once addressed to talk the instrument will send the response message it has available if any and then exit the talk addressed state
65. ency and Waveform Frequency The arb frequency is the clock rate of the data RAM address counters and has a range of 0 1Hz to 100MHz internal clock or DC to 50MHz external clock on this instrument The waveform frequency depends on both the arb frequency and horizontal size A 1000 point waveform clocked at an arb frequency of 100MHz has a waveform frequency of 100e6 1000 100KHZz e Data Value Each point in the waveform has an amplitude value in the range 2048 to 2047 e Arb Waveform Amplitude When playing arb waveforms the maximum output amplitude will depend on both the range of data values and the output amplitude setting A waveform that contains data values ranging from 2048 to 2047 will produce a maximum output which is 100 of the programmed peak to peak amplitude if the maximum range of the data values is only 1024 to 1023 for example the maximum output will only be 50 of the programmed level Selecting and Outputting Arbitrary Waveforms From the WAVEFORM FUNCTIONS screen the rotary knob or cursor keys can be used to scroll the list forwards through the display Select the required arb waveform by pressing the associated soft key WAVEFORM FUNCTIONS Opulse train setup arb1l 1000 points Yarb2 1000 points 36 Frequency and Amplitude Control with Arbitrary Waveforms Frequency and Amplitude control work in essentially the same way as for standard waveforms with the following differences Frequency
66. end of the current waveform cycle when the trigger signal goes true again FSK The tone is output when the trigger signal goes true and the next tone is output immediately when the trigger signal goes true again Using 2 instruments with their outputs summed together it is possible to generate DTMF test signals Trigger Generator Internal source 0 005 Hz to 100kHz square wave adjustable in 10us steps 3 digit resolution Available for external use from the SYNC OUT socket OUTPUTS Main Output Output Impedance 50Q Amplitude 5mV to 20Vp p open circuit 2 5mV to 10Vp p into 509 Amplitude can be specified open circuit hi Z or into an assumed load of 500 or 600Q in Vpk pk Vrms or dBm Amplitude Accuracy 2 1mV at 1kHz into 509 Amplitude Flatness 0 2dB to 1MHz 0 4dB to 40MHz DC Offset Range 10V DC offset plus signal peak limited to 10V from 50Q DC Offset Accuracy Typically 3 10mV unattenuated Resolution 3 digits or 1mV for both Amplitude and DC Offset Sync Out Multifunction output user definable or automatically selected to be any of the following Waveform Sync A square wave with 50 duty cycle at the main waveform frequency or all waveforms a pulse coincident with the first few points of an arbitrary waveform Burst Done Produces a pulse coincident with the last cycle of a burst Trigger Selects the current trigger signal Useful for synchronizing burst or gated signals Sweep Sync Out
67. equency With type setto gate the frequency changes when the signal specified inthe source field goes to the level specified in the slope field onthe TRIGGER IN screen and continues until the level changes again at which point the current cycle is completed the output is then gated off until the next occurrence of the gating signal at which time the next frequency in the list is gated on The difference between triggered and gated tone changes is therefore that in triggered mode the signal changes phase continuously from one frequency to the next at the waveform zero crossing point immediately after the trigger signal whereas in gated mode there can be an off period between successive frequencies whilst the gate signal is not true With type setto fsk the frequency changes instantaneously and phase continuously at each occurrence of the signal edge specified inthe source and slope fields on the TRIGGER IN screen without completing the current waveform cycle this is true FSK Frequency Shift Keying tone switching The following diagrams demonstrate the differences between trigger gate and FSK tone switching for a list of 2 frequencies switched by a square wave positive slope specified on TRIGGER IN setup The maximum recommended tone frequencies and trigger gate switching frequencies for the three modes are as follows GATE Maximum tone frequency 50kHz maximum switching frequency lt lowest tone frequency TRIGGER Maximum ton
68. er opening the case for any reason ensure that all signal and ground connections are remade correctly before replacing the cover Always ensure all case screws are correctly refitted and tightened c Inthe event of part replacement becoming necessary only use components of an identical type see the Service Manual Installation Mains Operating Voltage Fuse 12 Check that the instrument operating voltage marked on the rear panel is suitable for the local supply Should it be necessary to change the operating voltage proceed as follows 1 Disconnect the instrument from all voltage sources 2 Remove the screws which retain the top cover and lift off the cover 4 5 To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting 3 Change the transformer connections following the diagram below Refit the cover and the secure with the same screws 6 Change the fuse to one of the correct rating see below 230V 115V 100V oOV 15 14 13 12 11 for 230V operation connect the live brown wire to pin 15 for 115V operation connect the live brown wire to pin 14 for 100V operation connect the live brown wire to pin 13 7 Refit the cover and the secure with the same screws 8 To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting 9 Cha
69. eriod onthe pulse setup screen When changing from this screen the number of points in the waveform is never changed just as with a true arb which means that the shortest period highest frequency that can be set is number of waveform points x10 00ns To achieve faster frequencies up to the specification limit the period must be changed from the pulse set up screen changing the frequency from the pulse set up screen causes the number of points to be reduced as the period is reduced for periods lt 1ms Pulse train Setup Pulse trains are turned on withthe pulse train soft key onthe WAVEFORM FUNCTIONS screen pressing the setup soft key beside pulse train calls the first of the setup screens Enter no of pulses in train 1 10 2 done next 40 The number of screens used for the setup depends on the number of pulses in the pulse train The first three screens define the parameters that apply to the whole pattern number of pulses overall pulse train period and baseline voltage subsequent screens define the pulse level width and delay for each pulse in turn 3 screens for pulse 1 then 3 screens for pulse 2 etc Pressing next on any screen calls the next setup screen finally returning the display to the WAVEFORM FUNCTIONS screen from which pulse train can be turned on and off pressing done returns the display directly to the WAVEFORM FUNCTIONS screen from any setup screen The pulse train is built only after next is pres
70. ess setup onthe MODE screen to access the TRIGGER GATE SETUP screen on which the start phase can be set TRIGGER GATE SETUP BURST CNT 0000001 PHASE 000 0 actual 000 0 The start phase i e the point on the waveform cycle at which the gated waveform starts can be selected by pressing the phase soft key followed by direct entries from the keyboard or by using the rotary control Since the waveform cycle is always completed at the end of the gated period the start phase is also the stop phase The phase can be set with a precision of 0 1 but the actual resolution is limited with some waveforms and at certain waveform frequencies as detailed below To indicate when this is the case the actual phase is shown in brackets as a non editable field below the programmed value To achieve start phase precision all waveforms are run in Clock Synthesis mode i e as if they were arbitrary waveforms when Gated mode is specified this limits actual frequency resolution to 8 digits for all waveforms although the normally DDS generated waveforms are still entered with 10 digit precision Sine cosine haversine etc waveforms are created as if they were arbitrary waveforms with the first point of the waveform exactly at the start phase each time the phase or frequency is changed the waveform is recalculate which can cause a slight lag if these parameters are being changed quickly with the rotary knob The phase resolution of true arbitr
71. evel 5 000 V amp done next The pulse level can be set on this screen between 5 0V and 5 0V by direct keyboard entries or by using the rotary control As with the baseline level described above the set pulse levels are only output if the amplitude setting is set to maximum 10Vpp into 50Q on the AMPLITUDE screen and terminated in 50Q Adjusting the amplitude scales both the peak pulse levels and baseline together thus keeping the pulse shape in proportion as the amplitude is changed exactly as for arb waveforms Actual output levels are doubled when the output is unterminated Note that by pressing the Pulse soft key on this and subsequent screens the pulse to be edited can be directly set from the keyboard or by using the rotary control this is useful in directly accessing a particular pulse in a long pulse train instead of having to step through the whole sequence 41 42 Pressing next calls the pulse width screen for the first pulse Pulse 1 width progrm 25 000000 us actual 25 000000 us gt done next The width can be entered directly from the keyboard or by using the rotary control Any value in the range 10 00ns to 99 99s can be programmed but the actual value may differ for this reason the actual pulse width is shown below the program width The variation between program and actual will only really be noticeable for very short pulse train periods only a few points in the pulse train and very lo
72. f the command lt nr1 gt A number with no fractional part i e an integer Any item s enclosed in these brackets are optional parameters If more than one item is enclosed then all or none of the items are required The commands which begin with a are those specified by IEEE Std 488 2 as Common commands All will function when used on the RS232 interface but some are of little use Frequency and Period These commands set the frequency period of the generator main output and are equivalent to pressing the FREQ key and editing that screen WAVFREQ lt nrf gt WAVPER lt nrf gt CLKFREQ lt nrf gt CLKPER lt nrf gt Set the waveform frequency to lt nrf gt Hz Set the waveform period to lt nrf gt sec Set the arbitrary sample clock freq to lt nrf gt Hz Set the arbitrary sample clock period to lt nrf gt sec Amplitude and DC Offset AMPL lt nrf gt AMPUNIT lt cpd gt ZLOAD lt cpd gt DCOFFS nrf gt Waveform Selection WAVE lt cpd gt PULSPER lt nrf gt PULSWID lt nrf gt PULSDLY lt nrf gt PULTRNLEN lt nrf gt Set the amplitude to lt nrf gt in the units as specified by the AMPUNIT command Set the amplitude units to lt VPP gt lt VRMS gt or lt DBM gt Set the output load which the generator is to assume for amplitude and dc offset entries to lt 50 gt 50Q lt 600 gt 600Q or lt OPEN gt Set the dc offset to lt nrf gt Volts Select the output waveform as lt SI
73. g exchange translation and storage of many types of waveform data It is compatible with many popular DSOs and all TTi waveform generation products Waveforms may be generated by equation entry freehand drawing combining existing waveforms or any combinations of these methods Data upload and download are possible via RS232 COM1 4 USB or GPIB subject to a compatible GPIB card being correctly installed and configured in your PC Both upload and download of waveform data are possible and where applicable data exchange via 3 5 in floppy disks in the Tektronix ISF format is available Text data may be read from the Windows clipboard and used to create a waveform The text data format is very free and will allow most lists of numbers with or without intervening text to be read as waveform data points Waveform data may also be pasted to the clipboard for insertion into other programs Waveforms are displayed in fully scaleable windows and may be manipulated graphically Any number of waveforms in any of the supported types may be displayed simultaneously On line help is available in three ways 1 The help menu contains a contents option from which you can go to any section of the on line help file or browse particular areas or the whole file It is also possible to use the Index and Find operations of the Windows help system to search for items which are not listed directly in the contents section 2 Some dialog boxes have a Hel
74. he done soft key returns the display to this SWEEP SETUP screen Sweep Range Pressing the range soft key calls the SWEEP RANGE screen SWEEP RANGE start 100 0 kHz stop 10 00 MHz Ocentr span done The maximum sweep range for all waveforms is 1mHz to 40MHZz including triangle ramp and squarewave which have different limits in unswept operation Sweep range can be defined by start and stop frequencies or in terms of a centre frequency and span Start and Stop soft keys permit the two end points of the sweep to be set directly from the keyboard or by using the rotary control the start frequency must be lower than the stop frequency but see Sweep Type for selecting sweep direction Pressing the centr span soft key changes the screen to permit entry in terms of centr frequency and sweep span about that frequency pressing the start stop soft key on that screen returns the display to the start and stop frequency form of entry Note that when the sweep is displayed in terms of centre frequency and span the span will always be the exact difference between start and stop frequencies but the centre frequency shown will be that of the frequency step nearest the true centre frequency see Principles of Sweep Operation section Sweep Time Pressing the time soft key calls the SWEEP TIME screen SWEEP TIME 0 05 sec done gt The sweep time can be set from 1ms to 999s with 3 digit resolution by direct keyboar
75. ill be available immediately the command is executed because of the sequential nature of all operations Set the Parallel Poll Enable Register to the value lt nrf gt Returns the value in the Parallel Poll Enable Register in lt nr1 gt numeric format The syntax of the response is lt nr1 gt lt rmt gt Set the Service Request Enable Register to lt nrf gt Returns the value of the Service Request Enable Register in lt nr1 gt numeric format The Syntax of the response is lt nr1 gt lt rmt gt Returns the value of the Status Byte Register in lt nr1 gt numeric format The syntax of the response is lt nr1 gt lt rmt gt Wait for operation complete true As all commands are completely executed before the next is started this command takes no additional action The generator has no self test capability and the response is always O lt rmt gt Query and clear execution error number register The response format is nr1 lt rmt gt Query and clear query error number register The response format is nri lt rmt gt Miscellaneous Commands LRN LRN lt character data gt RST RCL lt cpd gt SAV lt nrf gt TRG FILTER lt cpd gt BEEPMODE lt cpd gt BEEP LOCAL USBID Returns the complete set up of the instrument as a hexadecimal character data block To re install the set up the block should be returned to the instrument exactly as it is received The syntax of the response is LRN lt Character data gt lt
76. is is the case the actual phase is shown in brackets as a non editable field below the programmed value 31 To achieve start phase precision all waveforms are run in Clock Synthesis mode i e as if they were arbitrary waveforms when Triggered Burst is specified this limits actual frequency resolution to 8 digits for all waveforms although the normally DDS generated waveforms are still entered with 10 digit precision Sine cosine haversine etc waveforms are created as if they were arbitrary waveforms with the first point of the waveform exactly at the start phase each time the phase or frequency is changed the waveform is recalculated which can cause a slight lag if these parameters are being changed quickly with the rotary knob The phase resolution of true arbitrary waveforms is limited by the waveform length since the maximum resolution is 1 clock thus waveforms with a length gt 3600 points will have a resolution of 0 1 but below this number of points the maximum resolution becomes 360 number of points Square waves pulse and pulse train have no start phase adjustment phase is fixed at 0 A summary of start phase capabilities in Triggered Burst mode is shown in the table below Waveform Max Wfm Freq Phase Control Range amp Resolution Sine cosine haversine havercosine 2 5MHz 360 0 1 Square 2 5MHz 0 only Triangle 500kHz 360 0 1 Ramp 500kHz 360 0 1 Sin x x 500kHz 360 0 1 Pulse amp Pu
77. k increasing the DC offset beyond 5V will cause the message Offset Sum level may cause clipping The offset change will be accepted producing a clipped waveform and the user may then choose to change the output level or the offset to produce a signal which is not clipped clip will show in the display beside AMPLITUDE or DC OFFSET while the clipped condition exists 23 ERROR messages are shown when an illegal setting is attempted most generally a number outside the range of values permitted In this case the entry is rejected and the parameter setting is left unchanged Examples are 1 Entering a frequency of 1MHz for a triangle waveform The error message Frequency out of range for the selected waveform is shown 2 Entering an amplitude of 25Vpp The error message Maximum output level exceeded is shown 3 Entering a DC offset of 20V The error message Maximum DC offset value exceeded is shown The messages are shown on the display for approximately two seconds The last two messages can be viewed again by pressing the last error soft key on the UTILITY screen see System Operations section Each message has a number and the full list appears in Appendix 1 The default set up is for all warning and error messages to be displayed and for a beep to sound with each message This set up can be changed on the error menu on the UTILITY screen The error menu is shown below Oerror beep ON Oerror message ON warn
78. lipping Note that it is not possible to give a simple guide as to where the range breakpoints are because the use of DC Offset for example changes these points Within each range a SUM signal of 2Vpp will force the channel output from range minimum to range maximum if the amplitude is set to mid range the SUM signal needed to force the output to range maximum is about half i e 1Vpp To facilitate the setting of appropriate Sum and amplitude levels the output amplitude can also be changed from the SUM set up screen Press the CH1 soft key and adjust the amplitude with direct keyboard entries or by using the rotary knob Synchronising Two Generators Two generators can be synchronised together following the procedure outlined below It is possible to link more than two generators in this way but results are not guaranteed Synchronising Principles Frequency locking is achieved by using the clock output from the master generator to drive the clock input of a slave The additional connection of an initialising SYNC signal permits the slave to be synchronised such that the phase relationship between master and slave outputs is that specified on the slave generator s TRIGGER GATE set up screen Synchronisation is only possible between generators when the ratio of the master and slave frequencies is rational e g 3kHz can be synchronised with 2kHz but not with 7KHz Special considerations arise with waveforms generated
79. lse Train 10MHz 0 only Arbitrary 100MS s clock 360 360 length or 0 1 Gated Mode Gated mode is turned on with the gated soft key onthe MODE screen The setup soft key on this screen accesses the TRIGGER GATE SETUP screen on which the start phase is set The other parameters associated with Gated are seton the TRIGGER IN setup screen called by pressing the TRIG IN key source int force slope positive level 1 4 V period 1 00ms Gate Source The gate signal source can be selected with the source soft key onthe TRIGGER IN setup screen tobe int or ext With int selected the internal trigger generator is used to gate the waveform the duration of the gate is half the generator period see Internal Trigger Generator section With ext selected the gate duration is from the threshold level set on the specified edge of the signal at TRIG IN until the same level on the opposite edge the threshold and edge are set using the level and slope soft keys respectively Gate Polarity 32 f slope onthe TRIGGER IN setup screenis setto positive the gate will open at the threshold on the rising edge and close on the threshold of the falling edge of an external gating signal i e the gate signal is true when the TRIG IN signal is high Ifthe slope isset negative the gate signal is true when the TRIG IN signal is low The default setting of positive should be used for gating with the Internal Trigger Generator Start Phase Pr
80. lt setting for Sync Out when arbitrary waveforms are selectedis waveform sync this is a pulse that starts coincident with the first point of the waveform and is a few points wide Output Filter Setting The output filter type is automatically chosen by the software to give the best signal quality for the selected waveform The choice can however be overridden by the user and this is most probably a requirement with arbitrary waveforms To change the filter press the FILTER key to callthe FILTER SETUP screen 37 38 FILTER SETUP Omode auto A v type 40MHz eliptic The default mode is auto which means that the software selects the most appropriate filter With the setting on auto the type can be changed manually but the choice will revert to the automatic selection as soon as any relevant parameter is changed To override the automatic choice press the mode soft key to select manual The three filter choices which are either automatically selected or set manually with the type soft key are as follows e 40MHz elliptic The automatic choice for sine cosine haversine havercosine sinx x and triangle Would be the better choice for arb waveforms with an essentially sinusoidal content e 20MHz Bessel The automatic choice for positive and negative ramps arb and sequence e No filter The automatic choice for squarewave pulse and pulse trains May be the better choice for arb waveforms with an essentially rectangular
81. ly 1V i e a 2Vpp signal Modulation frequency range is DC to 100kHz When external SCM is selected the amplitude control is disabled the AMPLITUDE setup screen shows the message fixed by SCM 43 44 Sum External summing can be used to add noise to a waveform for example or to add two signals for DTMF Dual Tone Multiple Frequency testing In Sum mode an external signal applied to the SUM input on the rear panel is summed with the selected waveform Pressing the SUM key calls the SUM set up screen A source extv 2 00 Vpp Pressing the source soft key steps the Sum sources between off and external With ext selected the screen is as shown above Clipping will occur if the Sum input level attempts to drive the channel amplitude above the maximum 20Vpp open circuit voltage However the relationship between the SUM input and the maximum summed output depends not only on the Sum input level but also on the generator amplitude setting This is because the Sum input is applied to the amplifier chain prior to the output attenuators the amplifier itself is controlled over a limited range 10dB and the full amplitude range is achieved by switching in up to five 10dB attenuation stages The summed output cannot exceed the maximum of the range within which the output has been set by choice of amplitude setting it is up to the user to observe the waveforms when using external sum and to make adjustments if the waveform is c
82. m different ranges System Operations from the Utility Menu Pressing the UTILITY key calls a list of menus which give access to various system operations including storing recalling set ups from battery backed memory error messages power on settings and calibration Each of the following operations are accessed by pressing the appropriate soft key on the UTILITY MENU Press UTILITY again at any time to return to the main Utility menu Storing and Recalling Set ups Complete set ups can be stored to or recalled from non volatile memory using the screens called by the store and recall soft keys Pressing store calls the screen Save to store No 1 gt execute Nine stores numbered 1 to 9 inclusive are available Select the store using the rotary control or direct keyboard entry and press to execute implement the store function Pressing recall orthe RECALL front panel key calls the RECALL screen Recall store No 1 set defaults execute The required set up is selected using the rotary control or direct keyboard entry and the recall is actioned with the execute soft key The factory defaults see Appendix 3 can be recalled using the set defaults soft key Note that loading the defaults does not change any arbitrary waveforms or stored setups or the RS232 GPIB USB interface settings Warnings and Error messages The default setup is for all warning and error messages to be displayed and for a beep to sound with each
83. n be switched between VCA and SCM with alternate presses of the type soft key External modulation can be used with external Sum External VCA Select VCA withthe type soft key onthe MODULATION screen Connect the modulating signal to the MODULATION IN socket on the rear panel nominally 1kQ input impedance a positive voltage increases the output amplitude and a negative voltage decreases the amplitude Note that clipping will occur if the combination of amplitude setting and VCA signal attempts to drive the output above 20Vpp open circuit voltage External AM is achieved by setting the required output level and applying the modulation signal which can be AC coupled if required at the appropriate level to obtain the modulation depth required If the output level is changed the amplitude of the modulating signal will have to be changed to maintain the same modulation depth The VCA signal is applied to the amplifier chain prior to the output attenuators The amplifier itself is controlled over a limited range 10dB and the full amplitude range is achieved by switching in up to five 10dB attenuation stages Peak modulation cannot exceed the maximum of the range within which the channel output has been set by choice of amplitude setting it is up to the user to observe the waveforms when using external VCA and to make adjustments if the waveform is clipping Note that it is not possible to give a simple guide as to where the range break
84. n that the ratio of frequencies between master and slave must be rational and each generator can be set to any waveform but see Synchronising Principles section above The master has its REF CLOCK IN OUT setto master onthe REF CLOCK menu called by the ref clock soft key on the UTILITY screen see System Operations section ref clk input Repeated presses of the ref clk soft key toggle between input output master and slave The slave is setto slave Setting the slave generator to slave forces the slave s mode to continuous and defaults the SYNC OUT output to phase lock The phase relationship between the slave and the master is set on the TRIGGER GATE set up screen of the slave accessed by pressing the triggered set up soft key onthe MODE screen see the Start Phase section of the Triggered Burst and Gate chapter 45 TRIGGER GATE SETUP burst cnt 0000001 Ophase 000 0 actual 000 0 The convention adopted for the phase relationship between generators is that a positive phase setting advances the slave generator with respect to the master and a negative setting delays the slave generator Hardware delays become increasingly significant as frequency increases causing additional phase delay between the master and slave However these delays can be largely nulled out by backing off the phase settings of the slave Typically these hardware delays are as follows DDS waveforms lt 25ns lt 1 to 1
85. nd the circuit output is connected to an oscilloscope or for slow sweeps a recorder An oscilloscope or recorder can be triggered by connecting its trigger input to the generator s SYNC OUT SYNC OUT defaults to sweep sync when sweep is turned on sweep sync goes low at the start of sweep and high for the duration of the last frequency step at the end of sweep depending on the sweep time set this should be long enough for an oscilloscope to retrace for example To show a marker on the display instrument the SYNC OUT can be set to additionally output a marker pulse See Sweep Marker section for setting marker frequency For triggered sweeps a trigger signal may be provided by any of the possible trigger sources i e internal external manual or remote The generator does not provide a ramp output for use with X Y displays or recorders Setting Sweep Parameters Pressing the SWEEP key or the sweep setup soft key onthe MODE screen displays the SWEEP SETUP screen SWEEP SETUP off Orange type Otime spacing marker 26 Menus for setting up the range time sweep rate type continuous triggered etc spacing lin log and marker position are all accessed from this screen using the appropriate soft key In addition Sweep Mode itself is turned on and off with alternate presses of the on off soft key sweep can also be turned on by the sweep soft key on the MODE screen On all the following menus pressing t
86. nded for operation from a normal single phase supply This instrument has been tested in accordance with EN61010 1 and has been supplied in a safe condition This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to retain the instrument in a safe condition This instrument has been designed for indoor use in a Pollution Degree 2 environment in the temperature range 5 C to 40 C 20 80 RH non condensing It may occasionally be subjected to temperatures between 5 and 10 C without degradation of its safety Do not operate while condensation is present Use of this instrument in a manner not specified by these instructions may impair the safety protection provided Do not operate the instrument outside its rated supply voltages or environmental range WARNING THIS INSTRUMENT MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action must not be negated by the use of an extension cord without a protective conductor When the instrument is connected to its supply terminals may be live and opening the covers or removal of parts except those to which access can be gained by hand is likely to expose live parts The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or
87. ng periods each of the 50 000 points has a long dwell time for exactly the same reasons as described in the Pulse Setup section refer to that section for a detailed explanation Pressing next calls the pulse delay screen for the first pulse Pulse 1 delay progm 0 0000000 ns actual 0 0000000 ns done next The pulse delay is entered in the same way as pulse width and again the actual delay is shown below the program delay for the same reasons The delay value that can be entered must be in the range pulse train period 1 point positive values delay the pulse with respect to waveform sync from SYNC OUT negative values cause the pulse to be output before the waveform sync Pressing next on this screen calls the first of the 3 screens for setting the parameters of Pulse 2 and so on through all the pulses in the pulse train In this way all parameters of all pulses are set The pulse train is built when next is pressed on the last screen of the last pulse or if done is pressed on any screen Care must be taken that the set widths and delays of the individual pulses are compatible with each other and the overall pulse train period i e delays must not be such that pulses overlap each other and delays widths must not exceed the pulse train period unpredictable results will occur if these rules are not followed Once the pulse train has been defined the period can be adjusted irrespective of the pulse width and delay setting
88. nge the fuse to one of the correct rating see below Ensure that the correct mains fuse is fitted for the set operating voltage The correct mains fuse types are for 230V operation 500 mA T 250V HRC for 100V or 115V operation 1A T 250V HRC To replace the fuse disconnect the mains lead from the inlet socket and withdraw the fuse drawer below the socket pins Change the fuse and replace the drawer The use of makeshift fuses or the short circuiting of the fuse holder is prohibited Mains Lead When a three core mains lead with bare ends is provided it should be connected as follows Brown Mains Live Blue Mains Neutral Green Yellow Mains Earth WARNING THIS INSTRUMENT MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action must not be negated by the use of an extension cord without a protective conductor Mounting This instrument is suitable both for bench use and rack mounting It is delivered with feet for bench mounting The front feet include a tilt mechanism for optimal panel angle A rack kit for mounting in a 19 rack is available from the Manufacturers or their overseas agents Ventilation The generator uses a small fan fitted to the rear panel Take care not to restrict the rear air inlet or the vents at the front sides and underneath In rack mounted situa
89. or full details Power On Setting Pressing the power on soft key calls the POWER ON SETTING screen POWER ON SETTING default values restore last setup recall store 1 The setting loaded at power on can be selected with the appropriate soft key tobe default values the default setting restore last setup i e the settings at power down are restored at power up or any of the stored settings The complete list of set ups can be scrolled through with further presses of the recall _ soft key the cursor keys or the rotary control default values restores the factory default settings see Appendix 3 System Information The system info soft key calls the SYSTEM INFO screen which shows the instrument name and firmware revision When system info is pressed a checksum is also made of the firmware code and the result displayed this can be used when a firmware fault is suspected to check that the code has not got corrupted Calibration 48 Pressing calibration calls the calibration routine see Calibration section Calibration All parameters can be calibrated without opening the case i e the generator offers closed box calibration All adjustments are made digitally with calibration constants stored in EEPROM The calibration routine requires only a DVM and a frequency counter and takes no more than a few minutes The crystal in the timebase is pre aged but a further ageing of up to t5ppm can occur in the first
90. ote Command Summary Maintenance Appendix 1 Warning and Error Messages Appendix 2 SYNC OUT Automatic Settings Appendix 3 Factory System Defaults Appendix 4 Waveform Manager Plus Arbitrary Waveform Creation and Management Software 44 45 47 49 49 49 50 51 52 59 60 61 61 61 62 62 62 63 63 63 63 64 65 68 69 71 72 73 Introduction This synthesised programmable function generator has the following features Sinewaves up to 40MHz squarewaves up to 50MHz 11 standard waveforms available plus pulse and arbitrary User defined pulses and pulse trains with 10ns resolution Arbitrary waveforms up to 100MHz sampling frequency Up to 4 arbitrary waveforms of 4 to 64k points with 12 bit vertical resolution Triggering summing and modulation of all output waveforms e RS232 and USB and optional GPIB interfaces The instrument uses a combination of direct digital synthesis and variable clock techniques to provide high performance and extensive facilities in a compact instrument It can generate a wide variety of waveforms between 0 1mHz and 50MHz with high resolution and accuracy Arbitrary waveforms may be played back with 12 bit vertical resolution and from 4 to 65536 horizontal points All waveforms can be swept over their full frequency range at a rate variable between 1 millisecond and 15 minutes Sweep can be linear or logarithmic single or continuous Single sweeps can be triggered from the front
91. p button which when clicked will open the on line help file at the section containing the description of that dialog box 3 From most windows dialogues the F1 key will open the help file at the relevant section Waveform Manager allows you to keep waveforms for different projects separate from each other on your hard drive A project may be placed anywhere in any directory folder and all waveform files for that project will be stored in a structure below that directory A project is identified by a user defined name Each project maintains its own library of expressions 73 T Tlz Thurloby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England Telephone 44 0 1480 412451 Fax 44 0 1480 450409 e mail sales tti test com International website www tti test com UK website www tti co uk Book Part No 48591 1080 Issue 3
92. panel the trigger input or the digital interfaces Asweep marker is provided Amplitude Modulation is available for all waveforms and is controlled from an external generator via the MODULATION input socket Signal Summing is available for all waveforms and is controlled from an external generator via the SUM input socket All waveforms are available as a Triggered Burst whereby each active edge of the trigger signal will produce one burst of the carrier The number of cycles in the burst can be set between 1 and 1048575 The Gated mode turns the output signal On when the gating signal is true and Off when it is false Both Triggered and Gated modes can be operated from the internal Trigger Generator 0 005Hz to 100kHz from an external source dc to 1MHz or by a key press or remote command The signals from the REF IN OUT socket and the SYNC OUT socket can be used to phase lock two instruments This can be used to generate multi phase waveforms or locked waveforms of different frequencies The generator parameters are clearly displayed on a backlit LCD with 4 rows of 20 characters Soft keys and sub menus are used to guide the user through even the most complex functions All parameters can be entered directly from the numeric keypad Alternatively most parameters can be incremented or decremented using the rotary control This system combines quick and easy numeric data entry with quasi analogue adjustment when required The generator has RS2
93. points are because the use of DC Offset for example changes these points Within each range the maximum output setting at which clipping is avoided is reduced from range maximum to half this value as modulation is increased from 0 to 100 100 modulation will be achieved at this mid range setting with an external VCA signal of approximately 1Vpp Modulation frequency range is DC to 100kHz It is also possible to modulate a DC level from the generator with a signal applied to the MODULATION IN socket as follows Set the generator to external trigger onthe TRIGGER IN setup screen but do not apply a trigger signal to TRIG IN select squarewave The MAIN OUT is now set at the peak positive voltage defined by the amplitude setting pressing the key with AMPLITUDE displayed will set the level to the peak negative voltage This DC level can now be modulated by the signal applied to the MODULATION IN input External SCM Select SCM withthe type soft key onthe MODULATION screen Connect the modulating signal to the MODULATION IN input on the rear panel nominally 1kQ input impedance With no signal the carrier is fully suppressed a positive or negative level change at the modulation input increases the amplitude of the carrier Note that clipping will occur if the SCM signal attempts to drive the output above the 20Vpp open circuit voltage Peak modulation i e maximum carrier amplitude 20Vpp is achieved with an external SCM level of approximate
94. ppendix 1 Warning and Error Messages Warning messages are given when a setting may not give the expected result e g DC Offset attenuated by the output attenuator when a small amplitude is set the setting is however implemented Error messages are given when an illegal setting is attempted the previous setting is retained The last two warning error messages can be reviewed by selecting LAST ERROR from the UTILITY screen the latest is reported first Warning and error messages are reported with a number on the display only the number is reported via the remote control interfaces The following is a complete list of messages as they appear on the display Warning Messages 00 No errors or warnings have been reported 13 DC offset changed by amplitude 14 Offset Sum level may cause clipping 23 Offset will clip the waveform 24 Instrument not calibrated 30 Amplitude will clip the waveform 42 Trigger source is fixed to external in SLAVE mode 59 Trigger slope is fixed to positive in SLAVE mode 81 The programmed mod depth cannot be set 83 Numeric value too large switching to sample period Error Messages 101 Frequency out of range for the selected waveform 102 Sample clock frequency required exceeds 100MHz 103 Sample clock frequency required is less than 0 1Hz 104 Pulse pulse train period out of range for current set up 105 Pulse width cannot be greater than the period 106 Absolute value of pulse delay must be lt
95. put to the instrument is buffered in a 256 byte input queue which is filled under interrupt in a manner transparent to all other instrument operations The queue contains raw un parsed data which is taken by the parser as required Commands and queries are executed in order and the parser will not start a new command until any previous command or query is complete There is no output queue which means that the response formatter will wait indefinitely if necessary until the instrument is addressed to talk and the complete response message has been sent before the parser is allowed to start the next command in the input queue Commands are sent as lt PROGRAM MESSAGES3 gt by the controller each message consisting of zero or more lt PROGRAM MESSAGE UNIT gt elements separated by lt PROGRAM MESSAGE UNIT SEPARATOR gt elements A lt PROGRAM MESSAGE UNIT gt is any of the commands in the remote commands list A lt PROGRAM MESSAGE UNIT SEPARATOR gt Is the semi colon character BH lt PROGRAM MESSAGES gt are separated by lt PROGRAM MESSAGE TERMINATOR gt elements which may be any of the following NL The new line character OAH NL END The new line character with the END message SEND The END message with the last character of the message Responses from the instrument to the controller are sent as RESPONSE MESSAGES gt A lt RESPONSE MESSAGES gt consists of one lt RESPONSE MESSAGE UNIT gt followed by a lt RESPONSE MES
96. puts a trigger signal at the start of sweep to synchronize an oscilloscope or recorder Can additionally output a sweep marker Phase Lock Out Used to phase lock two generators Produces a positive edge at the 0 phase point Output Signal Level Logic levels of lt 0 8V amp gt 3V except for Sweep Sync Sweep Sync is a 3 level waveform low at start of sweep high for the duration of the last frequency step at end of sweep with a narrow 1V pulse at the marker point INPUTS Trig In Frequency Range DC 1MHz Signal Range Threshold level adjustable 5V maximum input 10V Minimum Pulse Width 50ns for Trigger and Gate modes 50us for Sweep mode Polarity Selectable as high rising edge or low falling edge Input Impedance 10kQ Modulation In Frequency Range DC 100kHz Signal Range VCA Approximately 1V pk pk for 100 level change at maximum output maximum input 10V SCM Approximately 1Vpk for maximum output Input Impedance Typically 1 KQ Sum In Frequency Range Signal Range Input Impedance Ref Clock In Out Set to Input Set to Output Set to Phase Lock Maximum Input Voltage INTERFACES DC 30 MHz Approximately 2 Vpk pk input for 20Vpk pk output maximum input 10V Typically 1kQ Input for an external 10MHz reference clock TTL CMOS threshold level Buffered version of the internal 10MHz clock Output levels nominally 1V and 4V from 50Q Used together with SYNC OUT on
97. r by the STB command which will return MSS in bit 6 or by a Serial Poll which will return RQS in bit 6 The Service Request Enable register is set by the SRE lt nrf gt command and read by the SRE command Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Not used RQS MSS This bit as defined by IEEE Std 488 2 contains both the Requesting Service message and the Master Status Summary message RQS is returned in response to a Serial Poll and MSS I s returned in response to the STB command ESB The Event Status Bit This bit is set if any bits set in the Standard Event Status Register correspond to bits set in the Standard Event Status Enable Register MAV The Message Available Bit This will be set when the instrument has a response message formatted and ready to send to the controller The bit will be cleared after the Response Message Terminator has been sent Not used Not used Not used Not used POWER ON COMMAND ERROR EXECUTION ERROR ERROR NUMBER IN EXECUTION ERROR REGISTER EER READ AND CLEAR QUERY ERROR ERROR NUMBER IN QUERY ERROR REGISTER QER READ AND CLEAR OPERATION COMPLETE 4 4 STANDARD EVENT STATUS REGISTER ESR READ AND CLEAR STANDARD EVENT STATUS ENABLE REGISTER ESE lt NRF gt SET TO lt NRF gt ESE READ STATUS BYTE REGISTER SERIAL POLL READ WITH RQS STB READ WITH MSS SERVICE REQUEST ENABLE RE
98. rmt gt The settings in the instrument are not affected by execution of the LRN command Install data for a previous LRN command Resets the instrument parameters to their default values see DEFAULT INSTRUMENT SETTINGS Recalls the instrument set up contained in store lt nrf gt The store number must be in the range 1 to 9 Saves the complete instrument set up to the set up file number lt nrf gt The store number must be in the range 1 to 9 This command is the same as pressing the MAN SYNC key Its effect will depend on the context in which it is asserted The interface command Group Execute Trigger GET will perform the same action as TRG Set the output filter to lt AUTO gt lt ELIP gt lt BESS gt or lt NONE gt Set beep mode to lt ON gt lt OFF gt lt WARN gt or lt ERROR gt Sound one beep Returns the instrument to local operation and unlocks the keyboard Will not function if LLO is in force Returns the instruments address Refer to Calibration section for remote calibration commands 64 CLS ESE lt nrf gt ESE ESR IDN ST LRN OPC OPC PRE lt nrf gt PRE RCL lt cpd gt RST SAV lt cpd gt SRE lt nrf gt SRE STB TRG TST WAI ABORT AMPL lt nrf gt AMPUNIT lt cpd gt ARBDATA lt cpd gt ARBDATACSV lt cpd gt ARBDEF lt cpd gt lt nrf gt lt bin data block gt ARBDEFCSV lt cpd gt lt nrf gt lt csv ascii da
99. ruments Clear status Clears the Standard Event Status Register Query Error Register and Execution Error Register This indirectly clears the Status Byte Register Set the Standard Event Status Enable Register to the value of lt nrf gt Returns the value in the Standard Event Status Enable Register in lt nri gt numeric format The syntax of the response is lt nr1 gt lt rmt gt Returns the value in the Standard Event Status Register in lt nr1 gt numeric format The register is then cleared The syntax of the response is lt nr1 gt lt rmt gt Returns the instrument identification The exact response is determined by the instrument configuration and is of the form lt NAME gt lt model gt 0 lt version gt lt rmt gt where lt NAMEs is the manufacturer s name lt MODEL gt defines the type of instrument and lt VERSIONs is the revision level of the software installed Returns ist local message as defined by IEEE Std 488 2 The syntax of the response if O lt rmt gt if the local message false or 1 lt rmt gt if the local message is true Sets the Operation Complete bit bit 0 in the Standard Event Status Register This will happen immediately the command is executed 63 OPC PRE lt nrf gt PRE SRE lt nrf gt SRE STB WAI TST EER QER because of the sequential nature of all operations Query operation complete status The syntax of the response is 1 lt rmt gt The response w
100. s A the instrument is Class A by product category Immunity EN61326 1998 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test methods limits and performance achieved were a EN61000 4 2 1995 Electrostatic Discharge 4kV air 4kV contact Performance A EN61000 4 3 1997 Electromagnetic Field 3V m 80 AM at 1kHz Performance A EN61000 4 11 1994 Voltage Interrupt 1 cycle 100 Performance A EN61000 4 4 1995 Fast Transient 1kV peak AC line 0 5kV peak signal lines and RS232 GPIB ports Performance A e EN61000 4 5 1995 Surge 0 5kV line to line 1kV line to ground Performance A f EN61000 4 6 1996 Conducted RF 3V 80 AM at 1kHz AC line only signal connections lt 3m not tested Performance A oJ According to EN61326 the definitions of performance criteria are Performance criterion A During test normal performance within the specification limits Performance criterion B During test temporary degradation or loss of function or performance which is self recovering Performance criterion C During test temporary degradation or loss of function or performance which requires operator intervention or system reset occurs Cautions To ensure continued compliance with the EMC directive the following precautions should be observed a connect the generator to other equipment using only high quality double screened cables b aft
101. s for the individual pulses because unlike a conventional pulse generator the individual pulse widths and delays are adjusted proportionally to the period as the period is changed Period can also be changed from the PULSE TRN PERIOD screen called by pressing the FREQ key with pulse train mode selected PULS TRN PER 100 00000 us freq period The new setting can be entered either as a period in the way already described or as a frequency by first pressing the freq soft key However changing the period frequency from this screen is slightly different from changing period on the pulse train setup screen When changing from this screen the number of points in the waveform is never changed just as with a true arb which means that the shortest period highest frequency that can be set is the number of waveform points x 10 00ns To achieve faster frequencies up to the specification limit the period must be changed from the pulse train set up screen changing the frequency from the pulse train set up screen causes the number of points to be reduced as the period is reduced for period lt 1 00ms Modulation External modulation can be set to VCA Voltage Controlled Amplitude or SCM Suppressed Carrier Modulation modes Pressing the MODULATION key calls the MODULATION set up screen MODULATION source ext type VCA The source soft key steps the modulation choice between off and external With ext selected the modulation ca
102. sed after the last parameter setup or whenever done is pressed assuming a change has been made The first screen shown above sets the number of pulses 1 10 in the pattern enter the number of pulses directly from the keyboard or by using the rotary control Pressing next calls the pulse train period screen Pulse train period 100 00000 us 10000pt 10 000000ns done next The period can be set with 8 digit resolution from 40 00ns to 100s by direct keyboard entries or by using the rotary control Pressing next calls the baseline voltage screen the last of the general setup screens Enter the baseline voltage 0 000 V done next The baseline is the signal level between the end of one pulse and the start of the next i e it is the level all pulses start and finish at The baseline can be set between 5 0V and 5 0V by direct keyboard entries or by using the rotary control Note that the actual baseline level at the output will only be as set in this field if the output amplitude is set to maximum 10Vpp into 50Q on the AMPLITUDE screen and terminated in 50 If the amplitude was set to 5Vpp into 500 then the actual baseline range would be 2 5V to 2 5V for set values of 5 0 to 5 OV i e the amplitude control scales the baseline setting The actual output levels are doubled when the output is unterminated Pressing next on this screen calls the first of 3 screens for the first pulse in the pattern Pulse 1 l
103. set offset of 1 50V Whenever the set DC offset is modified by a change in output level in this way a warning message that this has happened will be displayed Similarly because the DC offset plus signal peak is limited to 10V to avoid waveform clipping a warning message will be displayed if this condition is set This is explained more fully in the Warnings and Error Messages section The output attenuation is controlled intelligently to minimise the difference between the programmed and actual offset when the combination of programmed amplitude and offset allows this Thus when the offset is set to 150mV for example the amplitude can be reduced to nominally 50mVpp before the fixed attenuator causes the actual offset to be different from the programmed value Warnings and Error Messages Two classes of message are displayed on the screen when an illegal combination of parameters is attempted WARNING messages are shown when the entered setting causes some change which the user might not necessarily expect Examples are 1 Changing the amplitude from for example 2 5 Volts pk pk to 25mV pk pk brings in the step attenuator if a non zero offset has been set then this will now be attenuated too The message DC offset changed by amplitude willbe shown temporarily on the screen but the setting will be accepted in this case the actual attenuated offset will be shown in brackets below the set value 2 With the output level set to 10V pk p
104. sing STATUS again returns the display to the previous screen Further explanations will be found in the detailed descriptions of the generator s operation Principles of Editing 18 Each screen called up by pressing a front panel key shows parameter value s and or a list of choices Parameter values can be edited by using the ROTARY CONTROL in combination with the left and right arrowed CURSOR keys or by direct numeric keyboard entry choices are made using the soft key associated with the screen item to be selected The examples which follow assume factory default settings A diamond beside a screen item indicates that it is selectable hollow diamonds identify deselected items and filled diamonds denote selected items For example press MODE to get the screen shown below MODE continuous gated setup triggered setup The filled diamond indicates that the selected mode is continuous Gated or Triggered modes are selected by pressing the associated soft key which will make the diamond beside that item filled and the diamond beside continuous hollow This screen also illustrates how an ellipsis three dots following the screen text indicates that a further screen follows when that item is selected In the case of the MODE screen illustrated pressing the setup soft key on the bottom line brings up the TRIGGER SETUP menu note that selecting this item does not change the continuous gated triggered selection Some s
105. ssued for the new value to be accepted CALSTEP Step to the next calibration point For general information on remote operation and remote command formats refer to the following sections 51 Remote Operation The instrument can be remotely controlled via its RS232 USB or GPIB interfaces When using RS232 it can either be the only instrument connected to the controller or it can be part of an addressable RS232 system which permits up to 32 instruments to be addressed from one RS232 port Some of the following sections are general and apply to all 4 modes single instrument RS232 addressable RS232 USB and GPIB others are clearly only relevant to a particular interface or mode It is only necessary to read the general sections plus those specific to the intended remote control mode Remote command format and the remote commands themselves are detailed in the Remote Commands chapter Address and Baud Rate Selection For successful operation each instrument connected to the GPIB USB or addressable RS232 system must be assigned a unique address and in the case of addressable RS232 all must be set to the same Baud rate The instrument s remote address for operation on both the RS232 and GPIB interfaces is set via the remote screen on the UTILITY menu REMOTE interface RS232 Yaddress 05 Obaud rate 9600 With interface selected withthe interface soft key the selection can be stepped between RS232 USB and GPIB
106. ta gt ARBLEN lt cpd gt BEEP BEEPMODE lt cpd gt BSTCNT lt nrf gt CLKFREQ lt nrf gt Remote Command Summary Clear status Set the Standard Event Status Enable Register to the value of lt nrf gt Returns the value in the Standard Event Status Enable Register in lt nr1 gt numeric format Returns the value in the Standard Event Status Register in lt nr1 gt numeric format Returns the instrument identification Returns ist local message as defined by IEEE Std 488 2 Returns the complete set up of the instrument as a hexadecimal character data block approximately 842 bytes long Sets the Operation Complete bit bit 0 in the Standard Event Status Register Query operation complete status Set the Parallel Poll Enable Register to the value lt nrf gt Returns the value in the Parallel Poll Enable Register in lt nr1 gt numeric format Recalls the instrument set up contained in store lt nrf gt Resets the instrument parameters to their default values Saves the complete instrument set up store number lt nrf gt Set the Service Request Enable Register to lt nrf gt Returns the value of the Service Request Enable Register in lt nri gt numeric format Returns the value of the Status Byte Register in lt nr1 gt numeric format This command is the same as pressing the MAN SYNC key The generator has no self test capability and the response is always O lt rmt gt Wait for operation complete true exec
107. te their own application software for USB communication with the generator the relevant information is supplied on the CD containing the drivers themselves GPIB Interface The 24 way GPIB connector is located on the instrument rear panel The pin connections are as specified in IEEE Std 488 1 1987 and the instrument complies with IEEE Std 488 1 1987 and IEEE Std 488 2 1987 GPIB Subsets This instrument contains the following IEEE 488 1 subsets Source Handshake SH1 Acceptor Handshake AH1 Talker T6 Listener L4 Service Request SR1 Remote Local RL1 Parallel Poll PP1 Device Clear DC1 Device Trigger DT1 Controller Co Electrical Interface E2 GPIB IEEE Std 488 2 Error Handling 56 The IEEE 488 2 UNTERMINATED error addressed to talk with nothing to say is handled as follows If the instrument is addressed to talk and the response formatter is inactive and the input queue is empty then the UNTERMINATED error is generated This will cause the Query Error bit to be set in the Standard Event Status Register a value of 3 to be placed in the Query Error Register and the parser to be reset See the Status Reporting section for further information The IEEE 488 2 INTERRUPTED error is handled as follows If the response formatter is waiting to send a response message and a lt PROGRAM MESSAGE TERMINATOPR gt has been read by the parser or the input queue contains more than one END message then the instrument has been INTERRUPTED and
108. the pulse width and delay For periods above 1 00ms the maximum number of points in the waveform 100 000 becomes the factor determining pulse width and delay resolution For example with the period set to 100ms the smallest pulse width and delay increment is 1us 100ms 100 000 This may appear to cause significant errors at extreme settings e g setting 10ns in the above example will still give an actual width of 1us but in practical terms a 1 in 100 000 resolution 0 001 is quite acceptable Pulse period can be adjusted irrespective of the pulse width and delay setting e g can be set smaller than the programmed pulse width because unlike a conventional pulse generator pulse width and delay are adjusted proportionally as the period is changed For example if from the default pulse settings of 100uUs period 50us width the period is changed to 60us the pulse width actual changes to 30us even though the program width is still 50s to get a 50us width with the period at 60us the width must be re entered as 50us after the period has been changed Period can also be changed from the PULSE PERIOD screen called by pressing the FREQ key with Pulse mode selected PULSE PERIOD 100 00000 us freq period The new setting can be entered either as a period in the way already described or as a frequency by first pressing the freq _ soft key However changing the period frequency from this screen is slightly different from changing p
109. tions allow adequate space around the instrument and or use a fan tray for forced cooling 13 Connections Front Panel Connections MAIN OUT This is the 50Q output from the main generator It will provide up to 20V peak to peak e m f which will yield 10V peak to peak into a matched 50Q load It can tolerate a short circuit for 60 seconds Do not apply an external voltage to this output SYNC OUT This is a TTL CMOS level output which may be set to any of the following signals from the SYNC OUT screen waveform sync Burst done Trigger Sweep sync Phase lock A sync marker phase coincident with the MAIN OUT waveform For standard waveforms sine cosine haversines square triangle sinx x and ramp the sync marker is a squarewave with a 1 1 duty cycle with the rising edge at the 0 phase point and the falling edge at the 180 phase point For arbitrary waveforms the sync marker is a positive pulse coincident with the first few points addresses of the waveform Provides a signal during Gate or Trigger modes which is low while the waveform is active at the main output and high at all other times Provides a positive going version of the actual trigger signal internal external manual and remote all produce a trigger sync Goes low at the start of sweep and high for the duration of the last frequency step at the end of the sweep In addition a half amplitude marker pulse can be set to be output at any of th
110. trument must also be configured so that the value of ist can be returned to the controller during a parallel poll operation The instrument is configured by the controller sending a Parallel Poll Configure command PPC followed by a Parallel Poll Enable command PPE The bits in the PPE command are shown below a x omae SS S S Parallel poll enable wta o sense of the response bit 0 low 1 high Example To return the RQS bit bit 6 of the Status Byte Register as a 1 when true and a 0 when false in bit position 1 in response to a parallel poll operation send the following commands PRE 64 lt pmt gt then PPC followed by 69H PPE The parallel poll response from the generator will then be 00H if RGS is 0 and 01H if RQS is 1 During parallel poll response the DIO interface lines are resistively terminated passive termination This allows multiple devices to share the same response bit position in either wired AND or wired OR configuration see IEEE 488 1 for more information Status Reporting This section describes the complete status model of the instrument Note that some registers are specific to the GPIB section of the instrument and are of limited use in an RS232 environment Standard Event Status and Standard Event Status Enable Registers These two registers are implemented as required by the IEEE std 488 2 Any bits set in the Standard Event Status Register which correspond to bits set in the Standard Event Status En
111. ubsequently filtered before being passed to the main output connector 20 Bit RAM Z ADDRESS MAIN O P The main difference between DDS and Clock Synthesis modes is the way in which the addresses are generated for the RAM and the length of the waveform data Clock Synthesis Mode In Clock Synthesis mode the addresses are always sequential an increment of one and the clock rate is adjusted by the user in the range 100MH z to 0 1Hz The frequency of the waveform is clock frequency waveform length thus allowing short waveforms to be played out at higher repetition rates than long waveforms e g the maximum frequency of an 8 point waveform is 100e6 8 or 12 5 MHz but a 1000 point waveform has a maximum frequency of 100e6 1000 or 100kHz 20 Bits RAM ADDRESS CLOCK 0 1Hz to 100MHz Arbitrary waveforms have a user defined length of 4 to 65536 points Squarewaves use a fixed length of 2 points and pulse and pulse train have their length defined by the user selected period value 19 DDS Mode 20 In DDS mode Direct Digital Synthesis all waveforms are stored in RAM as 4096 points The frequency of the output waveform is determined by the rate at which the RAM addresses are changed The address changes are generated as follows The RAM contains the amplitude values of all the individual points of one cycle 360 of the waveform each sequential address change corresponds to a phase increment of the waveform of 360 4096
112. uency in 1kHz steps The display will auto range up or down as the frequency is changed provided that autoranging permits the increment size to be maintained this will in turn determine the lowest or highest setting that can be achieved by turning the control In the example above the lowest frequency that can be set by rotating the control is 1 KHz shown on the display as 1 000000000 kHz This is the limit because to show a lower frequency the display would need to autorange below 1kHz to xxx xxxxxxx Hz in which the most significant digit represents 100Hz i e the 1kHz increment would be lost If however the starting frequency had been set to 1 000000000 MHz i e a 100 Hz increment the display would have autoranged at 1kHz to 900 0000000 Hz and could then be decremented down to 100 0000000 Hz without losing the 100 Hz increment Turning the control quickly will step numeric values in multiple increments Principles of Operation The instrument operates in one of two different modes depending on the waveform selected DDS mode is used for sine cosine haversine triangle sinx x and ramp waveforms Clock Synthesis mode shown as vclk in the status menu is used for square pulse pulse train and arbitrary In both modes the waveform data is stored in RAM As the RAM address is incremented the values are output sequentially to a Digital to Analogue Converter DAC which reconstructs the waveform as a series of voltages steps which are s
113. uted before the next is started Aborts a phase locking operation Set the amplitude to lt nrf gt in the units as specified by the AMPUNIT command Set the amplitude units to lt VPP gt lt VRMS gt or lt DBM gt Returns the data from an arbitrary waveform Returns the data from an arbitrary waveform Define an arbitrary waveform with name lt cpd gt and length lt nrf gt and load with the data in lt bin data block gt Define an arbitrary waveform with name lt cpd gt and length lt nrf gt and load with the data in lt csv ascii data gt Returns the length in points of the arbitrary waveform lt cpd gt Set beep mode to lt ON gt lt OFF gt lt WARN gt or lt ERROR gt Sound one beep Set the burst count to lt nrf gt Set the arbitrary sample clock freq to lt nrf gt Hz 65 CLKPER lt nrf gt DCOFFS lt nrf gt EER FILTER lt cpd gt FORCETRG LOCAL LRN lt character data gt MOD lt cpd gt MODE lt cpd gt MODTYPE lt cpd gt OUTPUT lt cpd gt PHASE lt nrf gt PULSDLY lt nrf gt PULSPER lt nrf gt PULSWID lt nrf gt PULTRNBASE lt nrf gt PULTRNDLY lt nrf1 gt lt nrf2 gt PULTRNLEN lt nrf gt PULTRNLEV lt nrf1 gt lt nrf2 gt PULTRNMAKE PULTRNPER lt nrf gt PULTRNWID lt nrf1 gt lt nrf2 gt QER REFCLK lt cpd gt SUM lt cpd gt SWPCENTFRQ nrf gt SWPDIRN lt cpd gt SWPMKR lt nrf gt SWPSPACING lt cpd gt SWPSPAN lt nrf gt SWPSTARTFRQ lt nrf gt
114. waveform lt cpd gt must be one of ARB1 ARB2 ARB3 or ARB4 The data consists of binary coded values as specified for the ARBDEF command Due to the binary data block this command cannot be used over the RS232 interface Returns the length in points of the arbitrary waveform lt cpd gt Set the mode to lt CONTs gt lt GATE gt lt TRIG gt lt SWEEP gt or lt TONE gt Set the burst count to lt nrf gt Set the generator phase to lt nrf gt degrees This parameter is used for setting the trigger gate mode start stop phase and the phase difference when synchronising instruments Delete tone frequency number lt nrf gt thus defining the end of the list Set tone frequency number lt nrf1 gt to lt nrf2 gt Hz The third parameter sets the tone type 1 will give Trig 2 will give FSK any other value gives Gate type Set the sweep start frequency to lt nrf gt Hz Set the sweep stop frequency to lt nrf gt Hz Set the sweep centre frequency to lt nrf gt Hz Set the sweep frequency span to lt nrf gt Hz Set the sweep time to lt nrf gt sec SWPTYPE lt cpd gt SWPDIRN lt cpd gt SWPSYNC lt cpd gt SWPSPACING lt cpd gt SWPMKR lt nrf gt Input Output control OUTPUT lt cpd gt SYNCOUT lt cpd gt TRIGIN lt cpd gt TRIGLEV lt nrf gt TRIGPER lt nrf gt FORCETRG Modulation Commands MOD lt cpd gt MODTYPE lt cpd gt SUM lt cpd gt Set the sweep type to lt CONT gt lt TRIG gt or lt TH
115. with successive presses of the soft key the cursor keys or by using the rotary control With address selected the soft key cursor keys or rotary control can be used to set the address the address setting is ignored in USB mode With baud rate selected the soft key cursor keys or rotary control can be used to set the baud rate for the RS232 interface When operating on the GPIB all device operations are performed through a single primary address no secondary addressing is used NOTE GPIB address 31 is not allowed by the IEEE 488 standards but it is possible to select it as an RS232 address Remote Local Operation 52 At power on the instrument will be in the local state with the REMOTE lamp off In this state all keyboard operations are possible When the instrument is addressed to listen and a command is received the remote state will be entered and the REMOTE lamp will be turned on In this state the keyboard is locked out and remote commands only will be processed The instrument may be returned to the local state by pressing the LOCAL key however the effect of this action will remain only until the instrument is addressed again or receives another character from the interface when the remote state will once again be entered RS232 Interface RS232 Interface Connector The 9 way D type serial interface connector is located on the instrument rear panel The pin connections are as shown below Pin Name Description 1
116. y or a remote command can be used to initiate a burst Trigger Edge The slope soft key is used to select the edge positive or negative ofthe external trigger signal that is used to initiate a burst The default setting of positive should be used for triggering by the Internal Trigger Generator Note thatthe trigger signal from SYNC OUT used for synchronising the display of a triggered burst on an oscilloscope for example is always positive going at the start of the burst Burst Count The number of complete cycles in each burst following the trigger is set from the TRIGGER GATE SETUP screen called by pressing setup onthe MODE screen TRIGGER GATE SETUP burst cnt 0000001 Ophase 000 0 actual 000 0 The required count can be set by pressing the burst cnt soft key followed by direct entries from the keyboard or by using the rotary control The maximum number of waveform cycles that can be counted is 1048575 27 1 Start Phase The start phase i e the point on the waveform cycle at which the burst starts can be selected by pressing the phase soft key followed by direct entries from the keyboard or by using the rotary control Since the waveform cycle is always completed at the end of the burst the start phase is also the stop phase The phase can be set with a precision of 0 1 but the actual resolution is limited with some waveforms and at certain waveform frequencies as detailed below To indicate when th

TG4001 Instruction Manual - English - Iss 3

Contents

Download Pdf Manuals

Related Search

Related Contents