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SEFRAM 4451 Specifications

1. 3 6 1 PARAM Menu This key selects and displays the pulse timing parameters the double pulse mode and allows changing the parameter data eee 10 0000 BS DUT 30 0 DEL O 0000 FS ee OTA DEL AS SIMGLE FREQ DUTY j E Parameter Menu F1 PERIOD FREQ Selects and displays the period or the pulse frequency Change the value using the shift keys rotary knob or numerical keys If a certain setting can t produce the waveform at the desired parameters the generator displays an error message While the pulse mode is set to external width on the value of the period may be changed but the value is not displayed since the actual value of the period is set by the external pulse F2 WIDTH DUTY Selects and displays the pulse width The minimum value of the width is 10ns with the maximum value dependent on the values of the period delay and transition times The Duty Cycle is defined as the ratio of the pulse width to the pulse period Changing the duty cycle will therefore change the width accordingly The duty cycle has both a value and a state on or off On Power On the duty cycle is off This means that the width is determined by the width parameter only The duty cycle is set to ON by entering a value The value may then be changed using the rotary encoder or the numeric keys When the duty cycle is on changing the period will cause a change in the width such that the duty cycle is kept constant The duty cycle is set to OF
2. F4 BRST Burst Triggers output N output cycles for each trigger event where N ranges from 2 to 999 999 F5 EXTWID In the external width EXT WID pulse mode the pulse period and width are determined by the externally applied signal The SEFRAM 4451 then applies transition and level parameters to this signal in order to generate the pulse The period width and delay may be changed but their change has no effect on the pulse and their values are not displayed The trigger mode may not be changed while the external width pulse mode is enabled EXTERHAL PULSE CONT TRIG BURST aikaan External Pulse After selecting the TRIG GATE or BURST menu the trigger source menu is available M4451 A00 27 Operating Manual SEFRAM 4451 PERIOD 10 0000 pS Trig Level 0 00 y War IMT EXT Majass FFE PETE BEREITS Trigger Menu F1 MAN Selects manual as the trigger source Pressing the MAN TRIG key generates the trigger In the Gate trigger mode the pulse is generated as long as the key is being pressed F2 INT Selects the internal trigger generator as the trigger source Change the internal trigger rate displayed with the rotary input knob or numerical keys The rate has a range of 100ns to 99 99s although the minimum value is limited by the value of the period in that the rate cannot be less than the period PERIOD 10 0000 pS Trig Rate 10 00 ms Internal Trigger EXT Selects the e
3. SEFRAM 4451 CHECK Amplitude Accuracy Test SPECIFICATION PROCEDURE CHECK Internal Trigger Accuracy Test SPECIFICATION PROCEDURE CHECK GPIB Capability input with a 50Q termination Select leading and trailing times The Rise and Fall times measured between 10 and 90 points are within specification t 1 of setting 10mV into 50Q Connect the instrument OUTPUT to the oscilloscope input with a 50Q termination Change the high and low levels to obtain different signal amplitudes Select a period of 100us The signal amplitude measured is within specification 0 01 from 100ns to 100s Connect the instrument SYNC OUT to the counter input A set to measure period in Auto Trig mode Select INT TRIGGER mode on SEFRAM 4451 and change the rate to different values The trigger rate measured by the counter is within specification Connect the SEFRAM 4451 generator to a controller Each side of this connection must be fitted with a proper IEEE 488 interface Operate the instrument via the GPIB bus and change setting as desired This procedure assumes that the operator has some experience in programming the controller and is familiar with the GPIB standard M4451 A00 69 Operating Manual SEFRAM 4451 To contac us M4451 A00 SEFRAM Instruments et Systemes 32 rue E MARTEL BP55 F 42009 SAINT ETIENNE cedex 2 France Tel 0825 56 50 50 0 15 TTC mn Fax 04 7
4. 10 Examples TRIG LEV 5 56 QUERY Syntax TRIGger LEVel Examples TRIG LEV Response NR3 4 12 3 6 Trigger Slope This command is used to set the external trigger slope on which to trigger COMMAND TYPE Setting or Query SETTING Syntax TRIGger SLOPe lt ws gt POSitive NEGative Arguments Type Character Options POSitive NEGative Examples TRIG SLOP POS TRIG SLOP NEG QUERY 56 Operating Manual SEFRAM 4451 Syntax TRIGger SLOPe Examples TRIG SLOP Response POS NEG 4 12 4 Status Subsystem This subsystem controls the SCPI defined status reporting structures which are the QUEStionable and OPERation status registers and the error event queue The QUEStionable and OPERation status registers are mandated by SCPI and so are implemented but are not used by the hardware No status is ever reported through them and they are not detailed in this manual The following shows the STATus structure used STATus PRESet QUEue NEXT 4 12 4 1 Status Preset This command is used to set certain status values to defined values The OPERation and QUEStionable enable registers are cleared The Positive transition filters are set to 32767 The Negative transition filters are set to 0 Since the Questionable and Operation status registers are not used in the SEFRAM 4451 the PRESet command has no real effect COMMAND TYPE Setting only SETTING Syntax STATus PRESet 4 12 4 2 Error Queue Read This
5. 4 12 5 2 Error Queue Reading This query returns the first entry in the error queue and removes that entry from the queue It s function is identical to that of the STATus QUEue NEXT query COMMAND TYPE Query only QUERY Syntax SYSTem ERRor Response lt error number gt lt error description 4 12 5 3 SCPI Version This query is used to read the SCPI version to which the instrument complies COMMAND TYPE Query only QUERY Syntax SYSTem VERSion Response 1992 0 NR2 format 4 12 5 4 Security This command enables the instrument memory to be cleared The stored settings are cleared when the Security state is changed from ON to OFF and the instrument state is returned to the factory power on default COMMAND Setting or Query SETTING Syntax SYSTem SECurity STATe lt ws gt lt boolean gt Arguments Type Boolean Examples SYST SEC ON SSYST SEC OFF QUERY Syntax SYSTem SECurity STATe Response 0 1 4 12 5 5 Power on Buffer This command is used to set the Power On Buffer setting The instrument will power on with the setting stored in that buffer Setting the value to 99 will result in the instrument powering up in the state it was in before it was powered down 58 Operating Manual SEFRAM 4451 COMMAND Setting or Query SETTING Syntax SYSTem POBuffer lt ws gt lt buffer gt Arguments Type Numeric Range 0 to 99 Rounding To integer value Examples SYST
6. Key Function Comments PERIOD 500 ns Pulse period WIDTH 200 ns Pulse width DELAY Ons Pulse delay from Sync out DPDELAY 5 us Delay between pulses in double pulse mode HILVL 2 5 Pulse high level LOLVL 2 5 V Pulse low level MODE CONT Pulse mode N BURST 2 Waves per burst SLOPE POS Positive external trigger slope TLVL IV External trigger level TRIG SOURCE MAN Trigger source INT TRG RATE 1 ms Internal trigger rate OUTPUT OFF Output disabled PULSE MODE Normal Normal single pulse output MODULATION OFF Modulation execution RISE 5 ns Pulse rise time FALL 5 ns Pulse fall time 3 11 Displaying Errors At power on the pulse generator performs a diagnostic routine to check itself for problems If the diagnostic routine finds an error an error message is displayed The pulse generator also displays error messages when front panel settings are either invalid or may produce unexpected results M4451 A00 31 Operating Manual SEFRAM 4451 unit Error messages for SEFRAM 4451 Message Text Setting conflict Trig rate short Cause Can t have this parameter set with other parameters Internal trigger rate too short for pulse or burst Empty location Attempt to restore a non existent setting Calibration Error An error when performing unit calibration for service personnel only LCA load error Internal hardware error must re power the unit Output overload Verify unit calibration Incorrect entry An excessive loa
7. This form of data is comprised of a mnemonic made up of lower or upper case alpha characters As with Program Header mnemonics some Character Data mnemonics have short and long forms Only the short or the long form may be used 2 Boolean data Boolean data indicate that the parameter can take one of two states ON or OFF The parameter may be character type ON or OFF or numeric A numeric value is rounded to an integer A non zero result is interpreted as 1 ON and a zero result as 0 OFF Queries return the values 0 or 1 3 NRf This is a decimal numeric data type where NRI indicates an integer number NR2 indicates a fixed point real number and NR3 indicates a floating point real number All parameters that have associated units accept a suffix which may be specified using upper or lower case characters When the suffix is not specified the numeric value is accepted in the default units which are Hertz for frequency Seconds for time and Volts for voltage To set the period to 1 microsecond we can send one of the following commands PULS PER 1E 6 or PULS PER 1000NS The special forms of character data accepted as numbers as defined by SCPI are NOT accepted by the SEFRAM 4451 There are two types of Program Message Units Command Message Units and Query Message Units A Query differs from a Command in that the Program Header is terminated with a question mark For example the period might be queried with the
8. lt low level gt units Arguments Type NRf Units MV V default Range 10V to 9 5V Rounding To 10mV Examples VOLT LOW 4V QUERY Syntax SOURce VOLTage LEVel IMMediate LOW Examples VOLT LOW Response NRf CONSIDERATIONS 1 The high level must be greater than the low level 2 The difference between the levels must conform to 0 5V lt difference lt 10V 3 The low level may not be less than the low limit 4 12 1 4 Predefined High Voltage Level This command is used to set the predefined high level of the pulse The pulse will be set when the predefined USER levels are invoked to this high level COMMAND Setting or Query SETTING Syntax SOURce VOLTage LEVel IMMediate PHIGH lt ws gt lt predef high level gt units Arguments Type NRf Units MV V default Range 9 5V to 10V Rounding To 10mV Example VOLT PHIGH 4V QUERY Syntax SOURce VOLTage LEVel IMMediate PHIGH Example VOLT PHIGH Response NRf 4 12 1 5 Predefined Low Voltage Level This command is used to set the predefined low level of the pulse The pulse will be set when the predefined USER levels are invoked to this low level COMMAND Setting or Query SETTING Syntax SOURce VOLTage LEVel IMMediate PLOW lt ws gt lt predef low level gt units Arguments Type NRf Units MV V default Range 10V to 9 5V Rounding To 10mV Examples VOLT PLOW 4V M4451 A00 47 Operating
9. 500us to 10ms 52 Operating Manual SEFRAM 4451 M4451 A00 4 12 1 18 Trailing Edge Time This command is used to set the value of the trailing edge time If the edge tracking feature is ON changing the trailing edge will cause the same change in the leading edge Refer to 2 1 19 for the tracking control command COMMAND Setting or Query SETTING Syntax SOURce PULSe TRANsition TRAiling lt ws gt lt trail time gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range SNS to 10MS Rounding To current resolution Examples PULS TRAN TRA 50NS PULS TRAN TRAiling 85NS QUERY Syntax SOURce PULSe TRANsition TRAiling Examples PULS TRAN TRA Response NRf CONSIDERATIONS The allowed value of the trailing edge time is limited by the values of the period width and delay In addition the ratio between the transition times is limited to a maximum of 20 1 and both transition times must be in one of the following ranges 5ns to 100ns 50ns to 1 us 500ns to 10us 5us to 100us 50us to 1ms 500us to 10ms 4 12 1 19 Transition Time Tracking The SEFRAM 4451 enables the transition times to be either independent of each other or to track each other With tracking set to ON setting one of the transition times will cause the other transition time to be set to the same value When the tracking is off each transition time is set independently of the other In
10. Manual SEFRAM 4451 M4451 A00 QUERY Syntax SOURce VOLTage LEVel IMMediate PLOW Examples VOLT PLOW Response NRf 4 12 1 6 Predefined Voltage Levels This command is used to set the pulse voltage levels to predefined values Four predefined values are available as follows CMOS High level 5V Low level 0V TTL High level 2 4V Low level 0 4V ECL High level 0 8V Low level 1 8V USER User defined levels as set using the PHIGH and PLOW commands COMMAND Setting only SETTING Syntax SOURce VOLTage LEVel IMMediate PREDefined lt ws gt lt option gt Arguments Type Character Options CMOS TTL ECL USER Examples VOLT PRED ECL 4 12 1 7 High Voltage Limit This command is used to set the high limit of the pulse COMMAND TYPE Setting or Query SETTING Syntax SOURce VOLTage LIMit HIGH lt ws gt lt high limit gt units Arguments Type NRf Units MV V default Range 9 5V to 10V Rounding To 10mV Examples VOLT LIM HIGH 4V QUERY Syntax SOURce VOLTage LIMit HIGH Examples VOLT LIM HIGH Response NRf CONSIDERATIONS The high limit cannot be set to less than the high level 4 12 1 8 Low Voltage Limit This command is used to set the low limit of the pulse COMMAND TYPE Setting or Query SETTING Syntax SOURce VOLTage LIMit LOW ws low limit gt units Arguments Type NRf Units MV V default Range 10V to 9 5V Rounding To 10mV Examples VO
11. POB 99 QUERY Syntax SYSTem POBuffer lt ws gt MINimum MAXimum Response Power on buffer in NR1 format 4 13 IEEE 488 1 INTERFACE MESSAGES 4 13 1 GET Group Execute Trigger The GET is used by the SEFRAM 4451 as a trigger when it is in either the TRIGGER GATE or BURST modes with the trigger source set to BUS It has the same effect as the TRG common command 4 13 2 DCL Device Clear In response to the DCL the PG does the following a Clears the input buffer and the output queue b Resets the Message Processing Functions 4 13 3 SDC Selected Device Clear The response is as for the DCL message when device is addressed to listen 4 13 4 LLO Local Lockout Sending LLO when device is addressed to listen and controller is asserting the REN line will put the device into Remote with Lock out state locking out the front panel M4451 A00 59 Operating Manual SEFRAM 4451 4 14 SCPI COMMAND TREE 4 14 1 Root Node Root SOURCce OUTPut TRIGger STATus SYSTem 4 14 2 SOURce Subsystem SOURCce FREQuency VOL Tage PULSe CW FIXed 1 LIMit lt NRf gt l E IMMediate HIGH LOW NRf HIGH LOW PHIGh PLOW PR Defined PUE on lt NRf gt lt NRf gt lt NRf gt lt NRf gt TTL CMOS ECL USER PERiod EACCuracy POL rity Boolean NORMal COMPLement INVerted lt NRf gt WIDTh EWIDth HOLD lt NRf gt lt Boolean gt
12. SEFRAM 4451 The following tests are intended to verify that the SEFRAM 4451 operates properly and meets its specifications Perform the tests after a warm up period of 30 minutes at 25 C 5 C ambient temperature These tests may be used for periodic inspection and after repair If the instrument does not meet its specification please contact the SEFRAM service center Period Accuracy Test SPECIFICATION PROCEDURE CHECK Width Accuracy Test SPECIFICATION PROCEDURE CHECK Delay Accuracy Test SPECIFICATION PROCEDURE CHECK Transition Times Accuracy Test t 0 01 Connect the instrument SYNC OUT to the counter input set to measure period The period measured by the counter is within specification 0 5 of setting 500ps Connect the instrument OUTPUT to the counter input Select output levels of 2 5V and 2 5V and set the counter to Width 50Q termination slope and Auto trigger mode The width measured by the counter is within specification 0 5 of setting 500 ps Connect the instrument SYNC OUT to input A of the counter and the OUTPUT to input B Set the counter to TIME A B mode 50Q termination slope and OV trigger level Select delay times on the SEFRAM 4451 The delay time measured by the counter is within specification SPECIFICATION 5 of setting 2ns from 5ns to 100ms PROCEDURE Connect the instrument OUTPUT to the oscilloscope M4451 A00 68 Operating Manual
13. Syntax SOURce PULSe DCY Cle lt ws gt lt duty gt units Arguments Type NRf Units None Range 1 to 99 Rounding To0 1 Examples PULS DCYC 25 QUERY Syntax SOURce PULSe DCY Cle Examples PULS DCYC 4 12 1 13 Pulse Hold This command is used to determine whether the width or the duty cycle are to be held constant when the period is changed The duty cycle is termed to be ON when changes in the period cause changes in the width such that the duty cycle remains constant This state is achieved by specifying the DCYCle parameter in the HOLD command The duty cycle is set OFF by specifying the WIDTH parameter and then changes in the period will not affect the width When setting the duty cycle OFF the last value is remembered which is the value the duty cycle takes when it is next set ON COMMAND TYPE Setting or Query 50 Operating Manual SEFRAM 4451 SETTING Syntax SOURce PULSe HOLD lt ws gt lt option gt Arguments Type Character Options WIDTh DCYCle Examples PULS HOLD WIDTh PULS HOLD DCYC QUERY Syntax SOURce PULSe HOLD Examples PULS HOLD Response WIDT DCYC 4 12 1 14 External Width This command is used to enable or disable the external width function When enabled ON this function causes an externally applied pulse to be generated with the same width but with transition times and output levels as specified by the instrument When the external width is enabled the pulse
14. TRIG OUTPUT 14 WIDTH FASTEST TRANSITION TIMES SELECTED 3rd CORNER 3rd CORNER x X VARIABLE TRANSITION TIMES SELECTED 1ST CORNER 1ST CORNER Pulse Definitions Perlod and Delay Double Pulse Mode ACCURACY RANGE 90 AMPLITUDE Ar t SETTLING TIME 10 Pulse Definitions Sottling Time M4451 A00 34 Operating Manual SEFRAM 4451 Pulse Definitions TRIG OUTPUT 3rd CORNER HIGH LEVEL AMPLITUDE 50 i 1 1 1 1 1 IST CORNER i EADING TRAILING EDGE EDGE LOW LEVEL Pulse Definitions Hlgh and Low Levels TRIG OUTPUT FASTEST TRANSITION TIMES SELECTED _ 1 D 1 D ACTUAL DELAY VARIABLE TRANSITION TIMES SELECTED 1ST CORNER Pulse Definition Width Perlod and Delay M4451 A00 35 Operating Manual SEFRAM 4451 M4451 A00 36 Section 4 Programming 4 1 OVERVIEW This section provides detailed information on programming the SEFRAM 4451 via the IEEE 488 bus GPIB General Purpose Interface Bus The SEFRAM 4451 is programmable over the IEEE 488 bus and its message protocol is compatible with IEEE 488 2 The device command set is compatible with the SCPI 1992 0 standard The SCPI standard does not cover all the needs of the SEFRAM 4451 and so the standard has been added where necessary The command syntax as defined by the IEEE 488 2 and SCPI standards is briefly ex
15. WIDTh DCYCle DOUBIe TRANsition STATe DELay LEADing TRAiling Boolean lt NRf gt lt NRf gt lt NRf gt AUTO lt Boolean gt ONCE 4 14 3 OUTPut Subsystem OUTPut STATe 60 M4451 A00 Operating Manual SEFRAM 4451 4 14 4 TRIGger Subsystem TRIGger LEVel SLOPe lt NRf gt lt NRF gt POS NEG MODE SOURce CONT TRIG GATE BURS EXT BUS 4 14 5 STATus Subsystem STATus OPERation PRESet QUEue NEXT EVENt CONDition ENABle PTRansition NTRansition lt NRf gt lt NRf gt lt NRf gt OPERation EVENt CONDition ENABle PTRansition NTRansition lt NRf gt lt NRf gt lt NRf gt 4 14 6 SYSTem Subsystem M4451 A00 61 Operating Manual SEFRAM 4451 SYSTem CoMMuhnicate ERRor SEC rity POB ffer VERSion GPIB STATe lt NRf gt i ADDRess lt NRf gt M4451 A00 62 Operating Manual SEFRAM 4451 B7 B6 B5 BITS NUMBERS SYMBOLS 83836281 16 se Fg 112 17 ZS 113 18 18 114 19 8g 8 t 1 4 soc 161 20 s 1g s t a a 100 74 116 5 PPC 5 155 21 8 318 1 ENQ u 5 5 101 75 117 5 6 166 22 8 11 g ACK v 6 6 102 75 118 7 7 167 23 8 1 1 1 BEL 7 7 103 77 119 10 GET 8 170 24 1599 BS 8 8 58 104 78 120 14 TCT 151 9 171 25 188 1 HT
16. addition to the tracking being set ON or OFF the transition times can be made equal to each other using the ONCE parameter In this case a single shot tracking is effected When going from tracking OFF to ON the trailing edge is made to follow the leading edge COMMAND Setting or Query SETTING Syntax SOURce PULSe TRANsition TRAiling AUTO lt ws gt lt Option gt Arguments Type Boolean or Character Examples PULS TRAN TRA AUTO OFF PULS TRAN TRA AUTO ONCE QUERY Syntax SOURce PULSe TRANsition TRAiing AUTO Examples PULS TRAN TRA AUTO Response 0 1 4 12 1 20 Pulse Polarity 53 Operating Manual SEFRAM 4451 This command is used to control the polarity of the pulse which may be normal or complemented The COMPement and INVerted parameters are aliases either may be used COMMAND Setting or Query SETTING Syntax SOURce PULSe POLarity lt ws gt lt Option gt Arguments Type Character Options NORMal Normal polarity COMPlement complemeted INVerted complemeted Examples PULS POL NORM PULS POL INVerted QUERY Syntax SOURce PULSe POLarity Examples PULS POL Response NORM COMP 4 12 1 21 Enhanced Accuracy This command is used to stay compatible with old MODEL 550 It does nothing on SEFRAM 4451 COMMAND TYPE Setting or Query SETTING Syntax SOURce PULSe EACCuracy lt ws gt lt Boolean gt Arguments Type Boolean Examples PULS EACC ON QUERY Sy
17. any source of 100 240V 10 AC at a frequency from 48Hz to 66Hz The maximum power consumption is 50 VA M4451 A00 14 Operating Manual SEFRAM 4451 2 6 Grounding Requirements To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground This instrument is grounded through the ground conductor of the supplied three conductor ac power cable The power cable must be plugged into an approved three conductor electrical outlet WARNING Do not alter the ground connection Without the protective ground connection all accessible conductive parts including control knobs can render an electric shock The power jack and mating plug of the power cable meet IEC safety standards 2 7 Signal Connections The BNC connectors are OUTPUT Up to 10V peak to peak into 50 ohm impedance 20V into open circuit The instrument is protected from short circuit to ground TRIG IN 10 KQ impedance selectable positive or negative slope variable level from 10V to 10V Input protected to 15V SYNC OUT A positive pulse signal in phase with the main output TTL levels with a 50 ohm source impedance and with 3 5ns typical transition times 2 7 1 Maintaining Pulse Fidelity Due to the extremely fast pulse rise times obtained from the instrument special consideration must be given to preservation of pulse fidelity Even at low repetition rates high frequency components are present in the output wavef
18. i y 9 9 69 105 79 12 12 152 10 772 26 12315 LF j z A 10 106 7 122 3 33 53 11 173 27111 nM 153 1 173 27 1g131 VT ESC 1 68 107 78 123 14 154 12 174 28 119 9 FF 12 6C 108 7C 124 5 155 13 175 23 1318 1 m D 3 60 169 70 125 156 14 175 9 11139 n 4E 78 5E 110 7 126 17 117 15 157 15 177 T TT 1 SI RUBOUT F 15 AF 79 131 76 127 ADORESSED UNIVERSAL LISTEN TALK SECONDARY ADORESSES COMMANOS COMMANOS AODRESSES AOORESSES OR COMMANDS PPE PPO octal 25 PPU GPIB code NAK ASCII character hex 15 21 decimal 4 15 RS 232 Programming M4451 A00 63 Operating Manual SEFRAM 4451 4 15 1 General The INSTALLATION section of this manual describes the RS 232 C connection for the instrument Be sure that you have the Remote Mode set to RS 232 and correctly set the baud rate EIA standard RS 232 C specifies the electrical characteristics and pin out of a serial communication standard for connecting data terminal equipment DTE to data communication equipment DCE Data terminal equipment is usually devices such as terminals computers or printers that are the final destination for data Data communication equipment on the other hand is usually a modem or other device that converts the data to another form and passes it through The instrument can be configured only as a DCE so in most cases it can be connected with a straight through cable to
19. output cause aberrations on the output waveform In addition loads less than 50 ohms reduce the waveform amplitude while loads more than 50 ohms increase waveform amplitude Excessive distortion or aberrations caused by improper termination are less noticeable at lower frequencies To ensure pulse integrity follow these precautions 1 Use good quality 50 ohms coaxial cable and connectors 2 Make all connections tight and as short as possible 3 Use good quality attenuators if it is necessary to reduce pulse amplitudes applied to sensitive circuits 4 Use termination or impedance matching devices to avoid reflections 5 Ensure that attenuators and terminations have adequate power handling capabilities If there is a DC voltage across the output load use a coupling capacitor in series with the load The time constant of the coupling capacitor and load must be long enough to maintain pulse flatness Impedance Matching If the pulse generator is driving a high impedance such as the 1 Mohm input impedance paralleled by a stated capacitance of an oscilloscope vertical input connect the transmission line to a 50 ohms attenuator a 50 ohms termination and to the oscilloscope input The attenuator isolates the input capacitance of the device and terminates the pulse generator properly M4451 A00 22 Operating Manual SEFRAM 4451 3 6 MENU Keys These keys select the main menus for displaying or changing a parameter function or mode
20. parameter period width delay and duty cycle may not be specified Doing so will cause error 221 to be returned Also the double pulse mode may not be enabled while the external width is enabled COMMAND Setting or Query SETTING Syntax SOURce PULSe EWIDth lt ws gt lt Boolean gt Arguments Type Boolean Examples PULS EWID ON PULS EWID OFF QUERY Syntax SOURce PULSe EWIDth Examples PULS EWID Response 0 1 4 12 1 15 Double Pulse State This command is used to enable or disable the double pulse mode In this mode two pulses are generated per period The first pulse is generated at the time of the signal trigger and the second pulse is generated after a programmable delay This delay is set by either the PULSE DELAY or the PULSE DOUBLE DELAY command COMMAND Setting or Query SETTING Syntax SOURce PULSe DOUBle STATe lt ws gt lt Boolean gt Arguments Type Boolean Examples PULS DOUB ON PULS DOUB STAT OFF QUERY Syntax SOURce PULSe DOUBle STATe Examples PULS DOUB Response 0 1 4 12 1 16 Double Pulse Delay M4451 A00 51 Operating Manual SEFRAM 4451 M4451 A00 This command is used to set the delay of the second pulse from the time of the trigger in the double pulse mode It has exactly the same effect as the PULSE DELAY command and is included in the command set for compatibility purposes COMMAND Setting or Query SETTING Syntax SOURce
21. query returns the first entry in the error queue and removes that entry from the queue Its function is identical to that of the SYSTem ERRor query COMMAND TYPE Query only QUERY Syntax STATus QUEue NEXT Response error number lt error description 4 12 5 System Subsystem The SYSTem subsystem collects the functions that are not related to instrument performance The functions implemented in the SEFRAM 4451 are security GPIB address changing error queue reading SCPI version reading and power on buffer setting not SCPI defined The command structure is as follows SYSTem COMMunicate GPIB ADDRess numeric value gt ERRor VERSion SECurity STATe lt Boolean gt POBuffer numeric value 4 12 5 1 GPIB Address Change This command is used to set the GPIB address Setting the address to 31 puts the instrument in an off bus state in which it does not take part in communication over the GPIB M4451 A00 57 Operating Manual SEFRAM 4451 M4451 A00 Communication with the instrument can be resumed only by setting the address to a suitable value from the front panel COMMAND Setting or Query SETTING Syntax SYSTem COMMunicate GPIB ADDRess lt ws gt lt address gt Arguments Type NRf Range 0 to 31 Rounding To integer value Examples SYST COMM GPIB ADDR 20 QUERY Syntax SYSTem COMMunicate GPIB ADDRess Examples TRIG SLOP Response address in NR1 format
22. the bytes and decode them the bus handshake is not completed until room has been made for more bytes in the buffer This prevents a fast controller from overrunning the device with data If the user has sent part of a Program Message but not the Program Message Terminator and he wishes to abort the message decoding and execution the Device Clear command may be sent or front panel operation resumed in REMS only The Output Queue The device has a 100 byte long output queue in which it stores response messages for the controller to read If at the time a response message is formatted and the queue contains previously formatted response messages such that there is not enough place in the queue for the new message the device will put off putting the message in the queue until there is place for it The Status Byte MAV bit indicates when set that part or all of a response message is ready to be read Response Messages The device sends a Response Message in response to a valid query All queries return a single Response Message Unit and all query responses are generated at the time the query is parsed Coupled Commands Coupled Commands are either commands whose execution validity depends on the value of other parameters or commands whose execution changes the value of another parameter The execution of commands designated as being coupled is deferred until all other commands in the same Program Message have been executed The coupled
23. the pulse generator power on with the settings it had at the last power off Select any other value in the range from 1 to 98 to have the pulse generator power on with the settings that you have saved with SETUPS STORE in the range to 98 PERIOD 10 0000 HS Power On il Peran Setup Power On Menu 3 7 ON Key Use these key to control the main output signal A build in LED lights when the output is active 3 8 Cursor Movement Keys Use these keys to move the cursor when visible either left or right They are used in conjunction with the rotary input knob to set the step size of the rotary input knob 3 9 Rotary Input Knob Use this knob to increase and decrease numeric values or to scroll through a list The cursor indicates the low order position of the displayed value which changes when you rotate the knob for straight numeric entries only For other types of data the whole value changes when you rotate the knob 3 10 Power On Settings At power on the pulse generator performs a diagnostic self test procedure to check itself for errors M4451 A00 30 Operating Manual SEFRAM 4451 When the pulse generator finishes the diagnostic self test routine it enters the local state LOGS and assumes power on default settings if the POWER ON setting is at 0 You can program the pulse generator for any settings you want at power on as described earlier in this section The factory default settings are Power on Default Settings
24. the serial interface is continuously supplied with data the keyboard will appear to be inoperative to the user M4451 A00 64 Operating Manual SEFRAM 4451 M4451 A00 65 Operating Manual SEFRAM 4451 Section 5 Performance Check Procedure 5 1 Introduction This section contains the test procedures required to check the electrical performance as listed in the SPECIFICATIONS section of this manual 1 4 The checkout procedure is recommended for preliminary incoming inspection and operational control 5 2 Test Equipment The following table lists the equipment necessary to perform the performance tests Any equivalent equipment may be substituted for the recommended model Chapter 4 INSTRUMENT REQUIRED PERFORMANCE RECOMMENDED MODEL Termination Feedthrough 500 1 Termination Feedthrough 50Q 0 1 Oscilloscope 400MHz dual channel Universal Counter 200MHz dual channel 5 3 Electrical Checkout This electrical checkout procedure verifies the SEFRAM 4451 Programmable Pulse Generator operation Connect the generator main output to the scope input Use 50Q termination and RG58 cable Set the instrument as follows POWER ON PERIOD 500ns WIDTH 100ns HIGH LEVEL 2 5V LOW LEVEL 2 5V MODE CONTINUOUS OUTPUT ON PULSE SINGLE Observe a pulse waveform with a 5V peak to peak amplitude symmetrical around zero Change the period width and levels and check for proper display on the scope 5 4 Performance Tests M4451 A00 66 Operating Manual
25. the values of the period width delay and transition parameters PERIOD 10 0000 pS WD 3 0000 BS 5 0000 BS FERIOO OTH fua oed Ri FREQ DUTY DOUBLE Double Pulse 3 6 2 OUTPUT Menu The Output menu enables the pulse high and low levels to be set The levels are limited by four factors The absolute limits are 10V The high level must be greater than the low level The pulse amplitude must be between 0 1V and 10V p p into 50 ohms The levels cannot exceed the limits as set in the OUTPUT LIMITS menu M4451 A00 24 Operating Manual SEFRAM 4451 PERIOD 10 0000 pS HI LYL 5 00 V LO LVL 0 00 Sv OU ik M qnnm OUTPUT Menu F1 HILVL Selects the pulse high level voltage F2 LOLVL Selects the pulse low level voltage PREDEF Selects the predefine pulse output levels In addition to being able to set the levels to any value within the limits the user may also select one of four pre defined levels CMOS Low level LOLVL OV High level HILVL 5V TTL Low level LOLVL 0 4V High level 2 4V ECL Low level LOLVL 1 8V High level HILVL 0 8V USER User defined levels entered by using the USER menu PERIOD 10 0000 HS Predef TTL PREDEFINED OUTPUT Menu F5 OUTPUT LIMITS Allows entering limits for the output levels to protect external devices connected to the unit output PERIOD 10 0000 BS Hi Limit 10 0 v A LI Ord LU LOL PREU e
26. 7 57 23 23 E mail sales sefram fr Web www sefram fr 70 Operating Manual SEFRAM 4451 DECLARATION OF CE CONFORMITY according to EEC directives and NF EN 45014 norm DECLARATION DE CONFORMITE CE suivant directives CEE et norme NF EN 45014 SEFRAM INSTRUMENTS amp SYSTEMES 32 rue Edouard MARTEL 42100 SAINT ETIENNE FRANCE Declares that the below mentioned product complies with D clare que le produit d sign ci apr s est conforme The European low voltage directive 73 23 EEC NF EN 61010 1 Safety requirements for electrical equipment for measurement control and laboratory use La directive Europ enne basse tension CEE 73 23 NF EN 61010 1R gles de s curit pour les appareils lectriques de mesurage de r gulation et de laboratoire The European EMC directive 89 336 EEC amended by 93 68 EEC Emission standard EN 50081 1 Immunity standard EN 50082 1 La directive Europ enne CEM CEE 89 336 amend e par CEE 93 68 En mission selon NF EN 50081 1 immunit selon NF EN 50082 1 Pollution degree Degr de pollution 2 Product name D signation PULSE GENERATOR G n rateur d impulsionss Model Type 4451 Compliance was demonstrated in listed laboratory and record in test report number uL ALL SAINT ETIENNE the Name Position Aug 20 2008 T TAGLIARINO Quality Manager M4451 A00 71
27. F by changing the width value The instrument will store the last value of the duty cycle and set the duty cycle to this value when it is next set to ON The duty cycle has an absolute range of 1 to 99 but the actual value is limited by the values of the period delay and transition times M4451 A00 23 Operating Manual SEFRAM 4451 F3 DELAY This parameter is used in two instances The first is to set the delay of the pulse in the single pulse mode The delay governs the time from the SYNC signal to the start of the pulse The second instance is the double pulse mode Here the delay governs the time from the SYNC pulse to the second pulse The minimum and maximum values of the delay are dependent on the values of the period width and leading and trailing edge times The delay range is 0 to 9 80000s PERIOD 10 0000 pS WD 3 0000 RS 0 0000 5 PERIOD IOTH ae SINGLE FREQ DUTY Delay Menu F5 SINGLE DOUBLE The unit can be set to generate either a SINGLE pulse or a DOUBLE pulse In the double pulse mode the first pulse is generated without delay from the start and the second pulse in generated after a delay from the start of the period as determined by the DELAY parameter Thus in order to generate a double pulse the delay must first be set and then the double pulse may be set on The double pulse mode state is toggled using either the F5 key The minimum and maximum values of the delay are determined by
28. ITUDE point 3 13 Pulse Parameter Limitations The following formulas express the limits on Period Width and Delay Single Pulse per Period Modes Un delayed Delayed Counted Burst with single pulse mode Period Width Delay must be gt 10 ns 0 99 Period must be gt Width Delay Pulse max 10 00 s Pulse min Width Delay 10 ns but not less than 20 ns Width max Period 0 99 Delay 10 ns but not more than 9 89999 s Width min 10 ns Delay max Period 0 99 Width 10 ns but not more than 9 89998 s Delay min 0 Single Pulse Transition Time Restrictions Width must be gt 1 3 Leading Edge Period Width must be gt 1 3 Trailing Edge Double Pulse per Period Modes Paired Pulse and Counted Burst with Paired pulses Delay must be gt Width 0 99 Delay must be gt Width 10 ns Pulse max 10 00 s Pulse min Width Delay 10 ns but not less than 40 ns Width max 0 99 Delay 10 ns but not gt 4 85000 s Width min 10 ns Delay max Period 0 99 Width 10 ns but not gt 9 80000 s Delay min Width 10 ns Double Pulse Transition Time Restrictions Width must be gt 1 3 Leading Edge Delay Width must be gt 1 3 Trailing Edge Period Delay Width must be gt 1 3 Trailing Edge Internal Trigger Burst Mode M4451 A00 33 Operating Manual SEFRAM 4451 0 99 Trig Rate must be gt Period Burst Count
29. LT LIM LOW 4V 48 Operating Manual SEFRAM 4451 QUERY Syntax SOURce VOLTage LIMit LOW Examples VOLT LIM LOW Response NRf CONSIDERATIONS The low limit cannot be set greater than the low level 4 12 1 9 Pulse Period This command is used to set or query the period of the pulse COMMAND Setting or Query SETTING Syntax SOURce PULSe PERiod lt ws gt lt period gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range 20NS to 10S Rounding current resolution Examples PULS PER 1US PULS PER 400 6 QUERY Syntax SOURce PULSe PERiod Examples PULS PER Response NRf CONSIDERATIONS The allowed range of the period will be determined by the values of the width delay and transition times 4 12 1 10 Pulse Width This command is used to set or query the value of the pulse width If the duty cycle is ON when the width command is sent it is then set to OFF and changes in the period will no longer affect the width COMMAND Setting or Query SETTING Syntax SOURce PULSe WIDTh lt ws gt lt width gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range 10NS to 9 899998 Rounding To current resolution Examples PULS WIDT 25NS PULS WIDT 200E 9 QUERY Syntax SOURce PULSe WIDTh Examples PULS WIDT Response NRf CONSIDERATIONS The allowed range of the wi
30. PULSe DOUBle DELay lt ws gt lt delay gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range ONS to 9 800005 Rounding current resolution Examples PULS DOUB DELay 150NS QUERY Syntax SOURce PULSe DOUBle DELay Examples PULS DOUB DEL Response NRf CONSIDERATIONS The allowed range of the delay will be determined by the values of the period width and transition times 4 12 1 17 Leading Edge Time This command is used to set the value of the leading edge time If the edge tracking feature 1s ON changing the leading edge will cause the same change in the trailing edge Refer to 2 1 19 for the tracking control command COMMAND TYPE Setting or Query SETTING Syntax SOURce PULSe TRANsition _LEADing lt ws gt lt lead time gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range SNS to 1OMS Rounding To current resolution Examples PULS TRAN LEAD 50NS PULS TRAN 85NS QUERY Syntax SOURce PULSe TRANsition LEADing Examples PULS TRAN LEAD Response NRf CONSIDERATIONS The allowed value of the leading edge time is limited by the values of the period width and delay In addition the ratio between the transition times is limited to a maximum of 20 1 and both transition times must be in one of the following ranges 5ns to 100ns 50ns to 1 us 500ns to 10us 5us to 100us 50us to 1115
31. SEFRAM 4451 50 MHz PROGRAMMABLE PULSE GENERATOR OPERATING MANUAL Operating Manual SEFRAM 4451 M4451 A00 2 Operating Manual SEFRAM 4451 Page SAFETY SUMMARY Section 1 General Information 5 1 1 Introduction 8 1 2 Description 8 1 3 Safety Remarks 8 1 4 Specifications 9 Section 2 Installation 2 1 Introduction 14 2 3 Initial Electrical Inspection 14 2 4 Instrument Mounting 14 2 5 Power Requirements 14 2 6 Grounding Requirements 15 2 7 Signal Connections 15 2 8 GPIB Connections 18 Section 3 Operating Instructions 3 1 Introduction 21 3 6 Menu Keys 23 3 10 Power On Settings 30 3 12 Pulse Definitions 32 3 13 Parameter Limitations 33 Section 4 Programming 4 1 Overview 35 4 2 Device State 35 4 3 Interface Function Subsets 35 4 4 Device Address 36 4 5 Message Exchange Protocol 36 4 6 Instrument Identification 36 4 7 Instrument Reset 37 4 9 Command Syntax 37 4 10 Status Reporting 39 4 11 IEEE488 2 Common Commands 42 4 12 Instrument Control Commands 45 4 13 488 1 Interface Messages 60 4 14 SCPI Command Tree 61 M4451 A00 3 Operating Manual SEFRAM 4451 Section 5 Performance Check Procedure 66 5 1 Introduction 67 5 2 Test Equipment 67 5 3 Electrical Checkout 67 5 4 Performance Tests 68 Declaration of conformity 71 M4451 A00 Operating Manual SEFRAM 4451 Safety Summary The following safety precautions apply to both operating and maintenance personnel and must be observed during all phases of ope
32. SR is defined by IEEE 488 2 It is implemented in the SEFRAM 4451 as a byte whose bits have the following definitions Bit 0 Operation Complete OPC This bit is set in response to the common command being executed Bit 1 Request Control RQC Not implemented in the PG Bit 2 Query Error QYE This bit is set when either the controller is attempting to read data from the device when none is available or when data prepared for the controller to read has been lost 39 Operating Manual SEFRAM 4451 4 10 4 Bit3 Device Specific Error DDE This bit is set to indicate that a device operation did not execute due to some device condition Bit 4 Execution Error EXE This bit is set when the device could not execute a command due to the command being outside of it s capabilities For example a parameter being out of range Bit 5 Command Error CME This bit is set to indicate an error in the command syntax Bit 6 User Request This bit is not used by the SEFRAM 4451 Bit 7 Power On PON This bit is set when the device is powered on The SESR is queried using the ESR common query The SESR is paired with an enable register the Standard Event Status Enable Register SESER This register enables one or more events in the SESR to be reflected in the Status Byte ESB summary message bit The bits of the SESER correspond to those of the SESR Setting a bit in the SESER enables the correspondi
33. Y and VOLTAGE mnemonics are at the same level SOURCE FREQUENCY 2KHZ VOLTAGE HIGH 4V 3 When Program Message Units describe different subsystems a colon prefix must be used to reset the command reference to the root Here the frequency and the output state are set 38 Operating Manual SEFRAM 4451 SOURCE FREQUENCY 3KHZ OUTPUT STATE ON Common Commands may be inserted in the Program Message without affecting the instrument control command reference For example SOURCE VOLTAGE HIGH 4V ESE 255 LOW 2V 4 10 STATUS REPORTING 4 10 1 4 10 2 4 10 3 M4451 A00 The instrument is capable of reporting status events and errors to the controller using the IEEE 488 1 Service Request function and the IEEE 488 2 Status Reporting structure The Status Byte Status summary information is communicated from the device to the controller using the Status Byte STB The STB is composed of single bit summary messages each summary message summarizing an overlying Status Data Structure By examining the content of the STB the controller gains some information concerning the instrument s status The STB bits are defined as follows Bit 0 Unused Bit 1 Unused Bit2 Error event queue summary message EVQ This bit is set if the queue is not empty Bit 3 Questionable Status summary message This bit is not used by the SEFRAM 4451 Bit 4 Message Available summary message This bit is set whenever all or part of a messa
34. a computer but would require special cabling to connect to another DCE device The baud rate is the bit rate during the transmission of a word in bits per second Different devices use many baud rates but the baud rates of the two devices that are connected must be the same The instrument can be set to different baud rates ranging from 1200 to 115 000 as described in Section 3 Operating Instructions Data signals over the RS 232 C use a voltage of 3 V to 25V to represent a zero called a space and voltage of 3V to 25V to represent a one called a mark Handshake and control lines use 3 V to 25V to indicate a true condition and 3V to 25V to indicate a false condition When no data is being transmitted the idle state of the data lines will be the mark state To transmit a byte the transmitting device first sends a start bit to synchronize the receiver 4 15 2 RS 232 C Operation The RS 232 C standard is not very specific about many of the handshaking signals and it is therefore usually necessary to refer to the manuals for both of the devices being connected to determine the exact pin out signal definition and signal direction for the devices The serial interface implements the same SCPI command set as the GPIB interface The instrument is programmed by sending ASCII coded characters to the instrument When the instrument is in the remote mode remote command input has priority over any front panel control Therefore as long as
35. ading and trailing edge transition times are equal the time interval between the 50 points is the same as that between the first and third corners PERIOD is the time between the 50 points on the rising edges of two consecutive trigger outputs DELAY is the time between the 50 points on the rising edge of the TRIG OUTPUT pulse and the 50 point of the leading edge of the output pulse at fastest transition time When VARIABLE TRANSITION TIMES are selected the time interval between the 50 points of the actual pulse depends on both the WIDTH and TRANSITION TIME settings A trailing edge slower or faster than the leading edge respectively lengthens or shortens the 50 interval In effect the pulse edges pivot about the first and third corners while the interval between these corners remains fixed for a given width setting As long as the leading and trailing edge times are equal the selected width and the actual width are the same In the SINGLE or DOUBLE pulse mode the instrument defines PERIOD as the time between the 50 points on the leading edges of two consecutive trigger outputs DELAY in double pulse mode is the time between the leading edges of the first and second pulse using as a reference point 50 amplitude with fastest transition times M4451 A00 32 Operating Manual SEFRAM 4451 SETTLING TIME is the interval required for the pulse level to enter and remain in the specified level ACCURACY RANGE measured from the 90 AMPL
36. ands 4 11 3 1 OPC Operation Complete Command The operation complete command causes the device to generate the operation complete message in the Standard Event Status Register on completion of the selected device operation Command Type Common Command Syntax OPC Examples PULS PER 1US OPC The OPC command and the OPC query described below find use mainly when commands having relatively long execution times are executed although all SEFRAM 4451 commands execute without any appreciable delay 4 11 3 2 OPC Operation Complete Query The operation complete query places an ASCII character 1 in the output queue on completion of the selected device operation Command Type Common Query Syntax OPC Response ASCII character 1 Example PULS PER 1US OPC 4 11 3 3 WAI Wait to Continue Command This command is intended for use with overlapped commands No commands in the SEFRAM 445 are overlapped and so this command has no effect Command Type Common Command Syntax WAI 4 11 4 Status and Event Commands 4 11 4 1 CLS Clear Status The clear status command clears the SESR and Error Queue status data structures COMMAND Command Syntax CLS 4 11 4 2 ESE Standard Event Status Enable This command is used to set the value of the Standard Event Status Enable Register COMMAND TYPE Common Command or Query COMMON COMMAND Syntax ESE lt ws gt lt NRf gt Arguments Type NRf Range 0
37. anual SEFRAM 4451 Range Resolution Accuracy Double Pulse DELAY Range Resolution Accuracy DUTY CYCLE Range Resolution Accuracy 10ns to Period 10ns off time Up to 6 digits limited to 100 ps 0 5 of setting 500 ps 0 5 of setting 3 ns for the second pulse Ons to Period Width 10ns off time Up to 6 digits limited to 100 ps 0 5 of setting 500 ps to 99 3 digits 0 1 Limited by width and pulse accuracy OUTPUT CHARACTERISTICS AMPLITUDE High Level Range 9 90V to 10V into 50 ohms load 19 80V to 20V into open circuit Low Level Range Amplitude Range Resolution Accuracy Aberrations 10V to 9 90V into 50 ohms load 20V to 19 80V into open circuit 0 1V to 10V p p into 50 ohms load 20V p p max into open circuit 3 digits limited to 10mV 1 of setting 10 mV into 50 ohms 594 20mV into 50 ohms load for pulse levels between 5V Output Resistance 50 ohms Offset Accuracy TRANSITION TIMES Range M4451 A00 1 25 mV lt 6ns to 10ms variable Leading and trailing edges settable separately and limited to 20 1 ratio between settings into one of the following ranges 5ns 10 Operating Manual SEFRAM 4451 100ns 50ns 1 0us 500ns 10us 5 0us 100us 50us 1 0ms 500us 10ms 5 ms 100 ms Resolution 3 digits limited to 10 ps Accuracy 5 of setting 2ns Linearity l
38. commands are then grouped together according to their functionality and executed as a group All parameters of the SEFRAM 4451 are coupled 4 6 INSTRUMENT IDENTIFICATION The IDN common query is used to read the instrument s identification string The string returned has the following format SEFRAM 4451 0 V1 0 4 7 INSTRUMENT RESET The RST common command effects an instrument reset to the factory default power up state 4 8 SELF TEST The TST common query causes the device to perform a self test This self test consists of checking the status of the pulse generator s period pulse and output cards 4 9 COMMAND SYNTAX M4451 A00 36 Operating Manual SEFRAM 4451 4 9 1 General Command Structure The device commands are generally defined by the SCPI standard with the exception of those instrument functions for which SCPI commands do not as yet exist The Common Commands and Queries are defined by IEEE 488 2 The command syntax i e how a command is structured is defined by IEEE 488 2 4 9 2 The Program Message A Program Message is defined as a string containing one or more Program Message Units each of which is an instrument command or query Program Message Units are separated from each other by the Program Message Unit Separator The Program Message is terminated by the Program Message Terminator The Program Message Unit Separator consists of a semicolon optionally preceded and or followed by white spac
39. d in the SEFRAM 4451 SHI L4 SR1 DCI DTI E2 CO 44 DEVICE ADDRESS The GPIB address of the device may be set to any value from 0 to 31 The address may be changed from the front panel using the numeric keypad or the rotary encoder or via the GPIB itself using the command SYSTem COMMunicate GPIB ADDRess Operating Manual SEFRAM 4451 Setting the device to address 31 puts it in the off bus state In this state it will not respond to messages on the GPIB If the device is in the REMS when set to address 31 an internal return to local command will be given setting the device to the LOCS If the device is in the RWLS the return to local command is ignored and the device remains in the RWLS The only way to then re establish communication with the device over the GPIB is to cycle the power and to then change the address to that required from the front panel 4 5 MESSAGE EXCHANGE PROTOCOL 4 5 1 4 5 2 4 5 3 4 5 4 The device decodes messages using the Message Exchange Protocol MEP defined in IEEE 488 2 The following functions implemented in the MEP must be considered The Input Buffer The device has a 128 byte long cyclic input buffer Decoding of remote messages is begun as soon as the input buffer is not empty that is as soon as the controller has sent at least one byte to the device Should the input buffer be filled up by the controller faster than the device can remove
40. device not being in the correct state to execute the trigger 221 Settings conflict The parameter is out of range due to the current instrument state 222 Data out of range The parameter exceeds the absolute limits 4 10 5 3 Device Specific Errors An error specific to the device occurred The DDE bit bit 3 of the Standard Event Status Register is set Code Description 315 Configuration memory lost Device memory has been lost Check the back up battery 330 Self test failed 350 Queue overflow Error codes have been lost due to more than 10 errors being reported without being read 4 10 5 4 Query Errors M4451 A00 41 Operating Manual SEFRAM 4451 A query error indicates that the output queue control has detected a problem This could occur if either an attempt was made to read data from the instrument if none was available or when data were lost Data could be lost when a query causes data to be formatted for the controller to be read and the controller sends more commands without reading the data Code Description 410 Query INTERRUPTED Data were sent before the entire response of a previous query was read 420 Query UNTERMINATED An attempt was made to read a response before the complete program message meant to generate that response was sent 430 Query DEADLOCKED The input buffer and output queue are full and the controller is attempting to send more data In this case the output queue and input buff
41. ding of the output stage At power on the unit checks for valid calibration data Need to calibrate the A incorrect value entry or syntax error Width too high The width value is too high for the pulse period selected Set other level When the pulse amplitude is gt 10Vp p need to change the other pulse level Save to Flash failed When saving the instrument settings Need to save again the setting Out of range Attempt to set a value out of instrument limits or in conflict with other pulse parameters 3 12 Pulse Definitions The figures illustrate the various pulse parameter definitions Pulse HIGH LEVEL corresponds to the most positive level of the pulse Pulse LOW LEVEL corresponds to the most negative level of the pulse Pulse AMPLITUDE is defined as the difference between the HIGH LEVEL and LOW LEVEL values Transition time LEADING or TRAILING EDGE is the interval required for the pulse to go from 10 to 90 of the selected amplitude or vice versa The way in which the instrument defines pulse parameters makes a distinction between the selected pulse which assumes the fastest transition times and the actual pulse output The values specified for WIDTH PERIOD and DELAY are defined with reference to the point at which the selected pulse reaches 50 of the amplitude during the leading and trailing edges at the fastest transition time WIDTH is the time interval between the 50 points of the leading and trailing edges If the selected le
42. dth will be determined by the values of the period delay and transition times M4451 A00 49 Operating Manual SEFRAM 4451 M4451 A00 4 12 1 11 Pulse Delay This command is used to set the delay from the trigger signal to the start of the pulse in single pulse mode Although there exists a separate command for the double pulse delay both commands affect the same delay and so this command will also determine the time between the two pulses in the double pulse mode COMMAND Setting or Query SETTING Syntax SOURce PULSe DELay lt ws gt lt delay gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range ONS to 9 800005 Rounding current resolution Examples PULS DELay 25NS PULS DEL 200E 9 QUERY Syntax SOURce PULSe DELay Examples PULS DEL Response NRf CONSIDERATIONS The allowed range of the delay will be determined by the values of the period width and transition times 4 12 1 12 Pulse Duty Cycle This command is used to set the duty cycle of the pulse Once the duty cycle has been set it 1s considered to be ON and then changes in the period will automatically cause changes in the width such that the duty cycle is kept constant The duty cycle is set OFF by either setting the pulse width or by the PULSE HOLD WIDTH command Querying the duty cycle when it is off will return the value zero 0 COMMAND TYPE Setting or Query SETTING
43. e meet IEC safety standards M4451 A00 5 Operating Manual SEFRAM 4451 WARNING CAUTION CAUTION M4451 A00 To avoid electrical shock hazard disconnect power cord before removing covers Refer servicing to qualified personnel Before connecting the line cord to the AC mains check the rear panel AC line voltage indicator Applying a line voltage other than the indicated voltage can destroy the AC line fuses For continued fire protection replace fuses only with those of the specified voltage and current ratings This product uses components that can be damaged by electrostatic discharge ESD To avoid damage be sure to follow proper procedures for handling storing and transporting parts and subassemblies that contain ESD sensitive components Operating Manual SEFRAM 4451 M4451 A00 7 Section 1 General Information 1 1 Introduction This manual contains information required to operate program check and maintain the SEFRAM 4451 50 MHz PROGRAMMABLE PULSE GENERATOR 1 2 Description The SEFRAM 4451 is a high performance programmable pulse generator The instrument generates pulses with a repetition rate to 50 width from 1005 variable delay variable transition times and amplitude The pulses can be output in continuous triggered gated or burst mode with an internal or external trigger signal The SEFRAM 4451 can be remotely operated via the RS 232 or the IEEE488 interface bus and is SCPI c
44. e characters A white space character is defined as the ASCII characters in the ranges 00H 09H and 20 This range includes the ASCII control characters and the space but excludes the Linefeed character The Program Message Terminator consists of optional white space characters followed by one of three options Linefeed LF character ASCII 0A GPIB EOI bus line being set true on the last byte of the message LF being sent with EOI true The Program Message Unit can be divided into three sections as follows 4 9 2 1 Program Message Header The Program Header represents the operation to be performed and consists of ASCII character mnemonics Two types of Program Headers are used in the SEFRAM 4451 Instrument control headers and Common Command and Query headers A Program Header may consist of more than one mnemonic in which case the mnemonics are separated from each other by the colon For instrument control commands the mnemonics are specified by the SCPI standard and indicate the tree structure of the command set The first mnemonic indicates the subsystem being controlled Common Command and Query Program Headers consist of a single mnemonic prefixed by an asterisk The mnemonics consist of upper or lower case alpha characters Mnemonics may be written in either the long form in which the entire mnemonic is written out or the short form in which only a specified portion of the mnemonic is written out Some mnem
45. ed with the address set to decimal 10 The address can be changed from the front panel by using the SPCL menu refer to SPECIAL FUNCTIONS jo SHIELD CONNECT TO SIGNAL GROUND TWISTED PAIR WITH 11 ATN PRE a TWISTED PAIA WITH 10 SRQ TWISTED PAIR WITH 9 IFC TWISTED PAIR WITH 8 Ce NDAC TWISTED PAIR WITH 7 NRFD TWISTED PAIR WITH 6 ES DAV REN Ga EO D108 Ca oos Dio 7 Cil DIOS C23 5 13 CIO 1 ISO METRIC THREAD M3 5 x 2 6 24 Pin Micro Ribbon Series 57 Connector GPIB connector 2 9 RS 232 Connection The rear panel RS 232 connector is a standard DB 9 male connector configured as a DCE M4451 A00 18 Operating Manual SEFRAM 4451 DB 9 pin Name Note Computer DB25 Direction pin 1 8 In 2 RXD Receive Data 3 In 3 TXD Transmit Data 2 Out 4 N C Out 5 GND Signal ground 7 6 N C 6 In 7 RTS Request to Send 4 Out 8 CRS Clear to send 5 In 9 N C 2 10 RS 232 Configuration Before connecting the RS 232 interface the instrument must be properly configured Select UTILITY menu and then F4 RS232 for setting of the desired baud date The instrument use 8 data bits 1 stop bit no parity and baud rate from 1200 to 115K 1200 2400 4800 9600 19200 38400 57600 and 115000 M4451 A00 19 Operating Manual SEFRAM 4451 M4451 A00 20 3 1 General Description Section 3 Operating Instructions Th
46. ers will be cleared Parsing will resume after the END message is detected 440 Query UNTERMINATED after indefinite response A query was received in the same program message after a query requiring an indefinite response was formatted Essentially this means that the IDN common query and the ARB DATA query should not be followed by more query messages in the same program message 4 10 5 5 System Events System events have positive valued codes They are not defined by SCPI but are specific to the PG Code Description 401 Power on 402 Operation complete The OPC command as been executed 4 11 IEEE 488 2 COMMON COMMANDS AND QUERIES 4 11 1 System Data Commands The identification query command IDN enables unique identification of the device over the GPIB It returns a string with four fields Manufacturer name Model name Serial number 0 if not relevant Version number 4 11 2 Internal Operation Commands 4 11 2 1 RST Reset Command The Reset command resets the device and returns it to the factory default power up state Command Type Common Command Syntax RST 4 11 2 2 TST Self Test Query The self test query causes an internal self test to be performed This test consists of checking the status of the period pulse and output cards Command Type Common Query Syntax TST Response ASCII 0 if test passes ASCII 1 if test fails M4451 A00 42 Operating Manual SEFRAM 4451 4 11 3 Synchronization Comm
47. following query PULS PER Not all Program Message units have query forms such as STATUS PRESET and some Program Message Units might have only the query form such as SYSTEM VERSION The SEFRAM 4451 puts the response to the query into the output queue from where it may be read by the controller The Status Byte MAV bit is set to indicate to the controller that a response is ready to be read SCPI Command Structure SCPI commands are based on a hierarchical structure This allows the same instrument control header to be used several times for different purposes providing that the mnemonic occurs in a unique position in the hierarchy Each level in the hierarchy is defined as a node Mnemonics in the different levels are separated from each other by a colon The first Program Message Unit or command in a Program Message is always referenced to the root node Subsequent commands are referenced to the same level as the previous command A Program Message Unit having a colon as its first character causes the reference to return to the root This process is defined by IEEE 488 section A 1 1 Consider the following examples l The following command may be used to set the high and low levels of the pulse Note that the LOW command is referenced to the command preceding it The LOW mnemonic resides at the same node as the HIGH command SOURCE VOLTAGE HIGH 5V LOW 2V 2 This command sets the frequency and the high level The FREQUENC
48. ge is available for the controller to read The controller may be ready to read the response message before it is available in which case it can either wait until this bit is set or it can start to read In the second case the controller time out must be set so that the read action will not be aborted before the message has been read Bit 5 Event Status Bit ESB summary message This bit is set to indicate that one or more of the enabled standard events have occurred Bit 6 Request Service RQS This bit is set when the device is actively requesting service Bit 7 Operation Status summary message No Operation Status events are defined in the SEFRAM 4451 and so this bit is never set The STB is read by the controller during a serial poll If the RQS bit was set it is then cleared The STB may also be read by the STB common query Service Request Enabling Service request enabling allows the user to select which Status Byte summary messages may cause the device to actively request service This is achieved using the Service Request Enable Register which is an 8 bit register whose bits correspond to those of the STB The RQS bit in the STB is set when a bit in the STB is set and its corresponding bit in the service request enable register is set The service request enable register is set using the SRE common command and read using the SRE common query Standard Event Status Register The Standard Event Status Register SE
49. is section describes the displays controls and connectors of the SEFRAM 4451 Pulse Generator All controls for the instrument local operation are located on the front panel The connectors are located on both front and rear panels 50MHz PROGRAMMABLE PULSE GENERATOR CONT GES 500 0 nS WD 200 0 nS DEL O 0 nS SYNC OUT OUTPUT 0 0 E EEEBEEE Figure 3 1 SEFRAM 4451 Front Panel 1 Power ON OFF 2 Display Window 3 FI F5 Keys 4 MENU Keys 5 Rotary Knob 6 Modify Keys 7 Output ON 3 2 Display Window Applies and removes AC power to the unit Displays all instrument data and settings on a LCD Select the menu options that appear on the second line of the LCD display Menus differ depending on the selected parameter function or mode Select parameters functions or modes whose settings are to be displayed or changed Used to increment decrement numerical values or to scan through the possible selections Used to move the cursor when visible to either left or right Controls the main output signal A build in LED lights when output is ON The SEFRAM 4451 has a graphic LCD display that can display up to 160x80 dots When power on the unit a parameter and current settings appear in the display The bottom displays a menu that corresponds to the Operating Manual SEFRAM 4451 output parameter or mode displayed selected 3 3 Front Panel Controls 3 4 3 5 The front panel contr
50. mand header error 111 Header separator error 112 Program mnemonic too long The mnemonic must contain no less than 12 characters 113 Undefined header 114 Header suffix out of range 120 Numeric data error 121 Invalid character in number 123 Exponent too large IEEE 488 2 specifies maximum of 32000 124 Too many digits IEEE 488 2 specifies maximum of 255 digits in mantissa 128 Numeric data not allowed A different data type was expected 131 Invalid suffix 134 Suffix too long A maximum of 12 characters are allowed in a suffix 138 Suffix not allowed 140 Character data error 141 Invalid character data Incorrect character data were received 144 Character data too long Character data may contain no more than 12 characters 148 Character data not allowed 158 String data not allowed 168 Block data not allowed 178 Expression data not allowed 4 10 5 2 Execution Errors An execution error indicates that the device could not execute a syntactically correct command either since the data were out of the instrument s range or due to a device condition The EXE bit bit 4 of the Standard Event Status Register is set on occurrence of an execution error Code Description 200 Execution error 201 Invalid while in local An attempt was made to change an instrument setting while the instrument was in the LOCAL state 211 Trigger ignored The GET or TRG common command was ignored due to the
51. match impedance with the illustrated network the following conditions must exist R1 Z2 R2 _ 1 22 R2 R1 ZIR2 Zl R2 Therefore R2 Zl Z2 and R1 Z1 R2 Z2 Z1 or Rl fZ2 Z2 71 and R2 ZL 22 71 4451 00 16 Operating Manual SEFRAM 4451 2 7 3 For example to match a 50Q system to 1250 system Z1 equals 500 and Z2 equals 1250 Therefore 125 125 50 968 Q and R2 50 Ars 64 60 125 50 Although the illustrated network provides minimum attenuation for a purely resistive impedance matching device the attenuation as seen from one end does not equal that seen from the other end A signal E1 applied from the lower impedance source encounters a voltage attenuation A1 which is greater than and less than 2 as follows El Ril 1 2 22 1 A signal E2 applied from the higher impedance source Z2 encounters a greater voltage attenuation A2 which is greater than 1 and less than 2 Z2 Z1 DN E R2 ZI In the example of matching 50Q to 1250 Al 208 1 1 77 125 and joe PLUS 12443 64 6 50 The illustrated network can be modified to provide different attenuation ratios by adding another resistor less than R1 between Z1 and the junction of R1 and R2 When constructing such a device the environment surrounding the components should also be designed to provide smooth transition between the impedances Acceptable perf
52. na Eis OUTPUT LIMITS Menu M4451 A00 25 Operating Manual SEFRAM 4451 3 6 3 PULSE Menu PERIOD 10 0000 BS EDGES 5 00 mui mw PULSE Menu F1 RISE Selects the pulse Rise time Leading edge F2 FALL Selects the pulse Fall time Trailing edge F3 EQUAL Selects equal Rise Leading edge and Fall Trailing edge times F5 NORMAL COMPL Selects the Normal or Complement pulse mode PERIOD 10 0000 HS EDGES 5 00 5 COMPLEMENT Pulse Mode The transition time range is 5ns to 100ms but the value is limited to a 20 1 ratio between the transition times In addition both values must be within one of the following ranges 5ns 100ns 50ns lus 500ns 10us 5us 100us 50us 1ms 500us 10ms 5ms 100ms The transition times are also limited by the values of the period width and delay M4451 A00 26 Operating Manual SEFRAM 4451 3 6 4 MODE Menu Selects the output mode CONT Continuous TRIG Triggered GATE Gated BRST Burst and PHASE To select the output mode press MODE then press the function key that corresponds to the desired Mode menu option as shown PERIOD 10 0000 pS Cont Mode Menu F1 CONT Continuous Selects continuous output F2 TRIG Triggered Triggers one output cycle of the selected pulse for each trigger event F3 GATE Gated Triggers output cycles as long as the trigger source asserts the gate signal
53. ng event to set the ESB bit when it occurs The SESER is set with the ESE common command and queried with the ESE command query The Error Queue The error queue is used to store codes of errors detected in the device It is implemented as a cyclic buffer of length 10 When the error queue is not empty bit EVQ in the Status Byte is set The error queue is read with either one of the following two queries SYSTEM ERROR STATUS QUEUE NEXT The first error in the queue is returned and the queue is advanced 4 10 5 Error Codes M4451 A00 The negative error codes are defined by SCPI Positive codes are specific to the PG The error message is returned in the following form lt error number gt lt error description gt A table of error numbers and their descriptions is presented here No error reported 0 No error 40 Operating Manual SEFRAM 4451 4 10 5 1 Command Errors A command error is in the range 199 to 100 and indicates that a syntax error was detected This includes the case of an unrecognized header The occurrence of a command error causes the CME bit bit 5 of the Standard Event Status Register to be set Code Description 100 Command Error 101 Invalid character 102 Syntax error 103 Invalid separator 104 Data type error 105 GET not allowed 108 Parameter not allowed More parameters than allowed were received 109 Missing parameter Fewer parameters than necessary were received 110 Com
54. ntax SOURce PULSe EACCuracy Examples PULS EACC Response 0 1 4 12 2 OUTPut Subsystem The Output Subsystem controls characteristics of the source s output The OUTPut command controls whether the output is ON or OFF COMMAND Setting or Query SETTING Syntax OUTPut STATe lt ws gt lt Boolean gt Arguments Type Boolean Examples OUTP STAT ON OUTP OFF QUERY Syntax OUTPut STATe Response 0 1 4 12 3 Trigger Subsystem The Trigger Subsystem is used to control the waveform triggering It is not all SCPI compatible The command structure is as follows TRIGger MODE CONTinuous TRIGger GATE BURSt M4451 A00 54 Operating Manual SEFRAM 4451 M4451 A00 BURSt lt NRf gt SOURce lt MANual gt INTernal EXTernal BUS TIMer lt NRf gt LEVel lt NRf gt DELay lt NRf gt SLOPe POSitive NEGative 4 12 3 1 Trigger Mode This command is used to set the trigger mode It is not a standard SCPI command COMMAND TYPE Setting or Query SETTING Syntax TRIGger MODE lt ws gt lt option gt Arguments Type Character Options CONTinuous TRIGger GATE BURSt Examples TRIG MODE CONT TRIG MODE BURS QUERY Syntax TRIGger MODE Response CONT TRIG GATE BURS 4 12 3 2 Trigger Source This command is used to select the trigger source for use in the Trigger Gate and Burst trigger modes COMMAND Setting or Query SETTING Syntax TRIGger SOURce lt ws gt lt
55. olean gt ONCE POLarity NORMal COMPlement INVerted 4 12 1 1 Frequency The frequency command controls the frequency of the pulse in the continuous trigger mode It is the inverse of the period COMMAND Setting or Query SETTING Syntax SOURce FREQuency CW FIXed lt ws gt lt frequency gt units Arguments Type NRf Units MHz kHz Hz default Range 0 1Hz to SOMHz Rounding the resolution of the range Examples 5KHZ FREQ 5E3 QUERY Syntax SOURce FREQuency CW FIXed Examples FREQ Response NR3 CONSIDERATIONS FIXed is an alias for CW 4 12 1 2 High Voltage Level This command is used to set the high level of the pulse COMMAND TYPE Setting or Query SETTING Syntax SOURce VOLTage LEVel IMMediate HIGH lt ws gt lt high level gt units Arguments Type NRf Units MV V default Range 9 5V to 10V Rounding To 10mV Examples VOLT HIGH 4V QUERY Syntax SOURce VOLTage LEVel IMMediate HIGH Examples VOLT HIGH Response NRf CONSIDERATIONS 1 The high level must be greater than the low level 2 The difference between the levels must conform to 0 5V x difference lt 10V 3 The high level may not exceed the high limit 4 12 1 3 Low Voltage Level 46 Operating Manual SEFRAM 4451 This command is used to set the low level of the pulse COMMAND Setting or Query SETTING Syntax SOURce VOLTage LEVel IMMediate LOW lt ws gt
56. ols select display and change parameter function and mode settings Use the rotary input knob and the cursor movement keys to enter data into the pulse generator To change a setting 1 Press the key that leads to a required item 2 Move cursor using cursor keys to the appropriate position in the numeric field 3 Use the rotary input or the numerical keyboard to change the value of the displayed item Changes take effect immediately The following subsections describe the function of each front panel key and connector Connectors The function generator has two BNC connectors on the front panel and one on the rear panel where you can connect coaxial cables These coaxial cables serve as carrier lines for input and output signals delivered to and from the function generator Additionally for ATE 19 rack systems on the rear panel are two connectors for optional wiring of the front connectors to the rear panel Output Connector Use this connector to transfer the main output signal from the function generator Trig In Connector Use this connector to apply an external trigger or gate signal depending on the pulse generator setting to the generator Sync Out Connector Use this connector to output a positive TTL sync pulse generated at each pulse cycle Output Connections The pulse generator output circuits operate as a 50 ohms voltage source working into a 50 ohms load At higher frequencies un terminated or improperly terminated
57. ompatible 1 3 Safety Remarks The SEFRAM 4451 is a SAFETY CLASS 1 instrument Before operation review the SAFETY SUMMARY at the front of this manual Operating Manual SEFRAM 4451 1 44 SPECIFICATIONS The following specifications describe the instrument performance after a 20 minute warm up period into a 50 ohms load All timing characteristics are measured at 50 of amplitude with fastest edges PULSE FUNCTIONS Single One pulse at each selected period up to 50MHz repetition rate Double One pair of pulses at each period up to 25MHz repetition rate Both pulses have the same selected width the position of the second pulse set by the delay control OPERATING MODES Continuous Output continuous at programmed period rate Triggered Output quiescent until triggered by an internal external GPIB or manual trigger then generates one cycle at programmed period rate Gated Same as triggered mode except pulses are output for the duration of the gated signal The last cycle started is completed Burst Same as triggered mode for programmed number of cycles from 2 to 999 999 as set by the N BURST function External Width Trigger duration and rate sets pulse width and repetition TIMING CHARACTERISTICS PERIOD Range 20 ns to 10 s SOMHz to 0 1Hz repetition rate Resolution Up to 6 digits limited to 100 ps Accuracy 0 01 Jitter 0 0196 of setting 20ps on Period Width and Delay WIDTH M4451 A00 9 Operating M
58. on integer values are rounded before execution Example SAV 25 Stored setting location 0 stores the factory defaults and is a read only location Location 99 stores a copy of the current instrument setting and it too is read only 4 12 INSTRUMENT CONTROL COMMANDS Instrument control commands are grouped into logical subsystems according to the SCPI instrument model The commands are comprised of mnemonics indicating the subsystem to which the command belongs and the hierarchy within that subsystem When the command is to be referred to the Root node it should be prefixed with a colon Mnemonics appearing in square brackets are optional The character is used to denote a choice of specifications The lt ws gt is used to denote a white space character 4 12 1 SOURce Subsystem The Source Subsystem controls the frequency voltage and pulse characteristics The command structure is as follows SOURce FREQuency CW FIXed lt NRf gt VOL Tage LEVel IMMediate HIGH lt NRf gt LOW lt NRf gt PREDefined TTLICMOS ECL USER PHIGh lt NRf gt PLOW lt NRf gt HIGH lt NRf gt LOW lt NRf gt PULSe PERiod lt NRf gt WIDTh lt NRf gt DELay lt NRf gt DCYCle lt NRf gt HOLD WIDTh DCYCle EWIDth lt Boolean gt M4451 A00 45 Operating Manual SEFRAM 4451 M4451 A00 DOUBle STATe Boolean DELay lt NRf gt TRANSition LEADing lt NRf gt TRAiling lt NRf gt AUTO lt Bo
59. onics have only one form due to their short length Where a command is described the portion appearing in upper case is the short form Only the short form or the long form may be used Example The command to set the period to 1 microsecond may be written in the following ways SOURCE PULSE PERIOD 1US SOUR PULS PER 1US SOURCE PULSE PERIOD 1US Some mnemonics in a specified Program Header may be optional This is indicated in the command description by the mnemonic being enclosed in square brackets This means it is not necessary to write the mnemonic into the Program Header it is a default condition The SOURCE mnemonic for example is optional Not specifying it will cause the device to search for the mnemonics in the Program Header under the Source Subsystem For example the period may be set by the command PULS PER 1US 4 9 2 2 Program Message Header Separator The Program Header Separator is used to separate the program header from the program data It consists of one or more white space characters denoted as lt ws gt Typically it is a space 4 9 2 3 Program Message Data M4451 A00 37 Operating Manual SEFRAM 4451 4 9 3 M4451 A00 The Program Data represent the values of the parameters being set for example the 1US in the above examples Different forms of program data are accepted depending on the command The Program Data types used in the SEFRAM 4451 are as follows l Character program data
60. option gt Arguments Type Character Options MANual Front panel MAN key BUS GPIB trigger GET or TRG INTernal Internal trigger EXTernal External trigger Examples TRIG SOUR BUS TRIG SOUR INT QUERY Syntax TRIGger SOURce Response MAN BUS INT EXT 4 12 3 3 Burst Count Used to set the number of cycles to be output in the BURST mode It is not a standard SCPI command COMMAND Setting or Query SETTING Syntax TRIGger BURSt lt ws gt lt value gt Arguments Type NRf Range 2 to 999999 Rounding To integer value Examples TRIG BURS 100 55 Operating Manual SEFRAM 4451 M4451 A00 QUERY Syntax TRIGger BURSt Response NRf Examples TRIG BURSt 4 12 3 4 Internal Trigger Rate Sets the rate of the internal trigger COMMAND TYPE Setting or Query SETTING Syntax TRIGger TIMer lt ws gt lt value gt units Arguments Type NRf Units S seconds MS milliseconds US microseconds NS nanoseconds Range 100NS to 99 998 Rounding current resolution Examples TRIG TIM 10E 6 TRIG TIM 50005 QUERY Syntax TRIGger TIMer Examples TRIG TIM Response NR3 4 12 3 5 External Trigger Level Used to control the trigger level of the external trigger COMMAND TYPE Setting or Query SETTING Syntax TRIGger LEVel lt ws gt lt trigger level gt units Arguments Type NRf Units V mV Range 10V to 10V with 10mV resolution OV allowed Rounding
61. orm Use high quality coaxial cables attenuators and terminations RG 58 type coaxial cable and typical BNC connectors exhibit impedance tolerances which may cause visible reflections For maximum fidelity use short high quality 50 ohm coaxial cables When signal comparison measurements or time difference determinations are made the two signals from the test device should travel through coaxial cables with identical loss and time delay characteristics When making connections that are not in a 50 ohm environment keep all lead lengths short 1 4 inch or less M4451 A00 15 Operating Manual SEFRAM 4451 2 7 2 Impedance Matching A mismatch or different impedance in a transmission line generates a reflection back along the line to the source The amplitude and polarity of the reflection are determined by the load impedance in relation to the characteristic impedance of the cable If the load impedance is higher than the characteristic impedance of the line the reflection will be of the same polarity as the applied signal If it is lower the reflection will be of opposite polarity These reflections add or subtract from the amplitude of the incident pulse causing distortion and irregular pulse shapes Impedance matching network that provides minimum attenuation A simple resistive minimum attenuation impedance matching network that can be used to match the instrument output into relatively low impedance is shown in the above figure To
62. ormance can be obtained with discrete components using short lead lengths however a full coaxial environment is preferred The characteristic impedance of a coaxial device is determined by the ratio between the outside diameter of the inner conductor to the inside diameter of the outer conductor expressed as Ve D log 10 Eg Rise time Measurements in Linear Systems Consider the rise time and fall time of associated equipment when measuring the rise time or fall time of a linear device If the rise time of the device under test is at least ten times slower than the combined rise times of the instrument the monitoring oscilloscope and associated cables the error introduced will not exceed 1 and usually may be ignored If the rise time or fall time of the test device is less than ten times slower M4451 A00 17 Operating Manual SEFRAM 4451 than the combined rise times of the testing system determine the actual rise time of the device under test by using the following formula Rt Rt Ry Rts Rt equals the overall rise time or fall time of the entire measurement system and R1 R2 R3 etc are the rise times or fall times of the individual components in the system 2 8 GPIB Connections The rear panel GPIB connector is a AMPHENOL 57 10240 or equivalent and connects to a standard IEEE 488 bus cable connector The GPIB line screens are not isolated from chassis and signal ground The instrument is shipp
63. plained in the following sections Users who have experience programming GPIB instruments may skip these paragraphs and go directly to where the individual command syntax is given Users wishing to gain further insight should consult the standards 4 2 DEVICE STATE The device may be in one of the four possible states described below The transition between states is defined by IEEE 488 4 2 1 Local State LOCS In the LOCS the device may be operated from the front panel only Its settings may be queried over the GPIB but not changed Commands that do not affect the signal being output by the instrument are accepted 4 2 2 Local with Lockout State LWLS In the LWLS the device may be operated from the front panel only Its settings may be queried over the GPIB but not changed Commands that do not affect the signal being output by the instrument are accepted The difference between the LOCS and the LWLS is that from the LWLS the device may enter the Remote With Lockout State 4 2 3 Remote State REMS In the REMS the device may be operated from the GPIB Actuating any front panel key will cause the device state to revert to the LOCS 4 2 4 Remote with Lockout State RWLS In the RWLS the device is operable only from the GPIB Front panel operation may be returned by either sending an appropriate IEEE 488 command or by cycling the device power 4 3 INTERFACE FUNCTION SUBSETS The following interface function subsets are implemente
64. ration service and repair of this instrument Before applying power follow the installation instructions and become familiar with the operating instructions for this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument SEFRAM assumes no liability for a customer s failure to comply with these requirements This is a Safety Class I instrument GROUND THE INSTRUMENT To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground This instrument is grounded through the ground conductor of the supplied three conductor ac power cable The power cable must be plugged into an approved three conductor electrical outlet Do not alter the ground connection Without the protective ground connection all accessible conductive parts including control knobs can render an electric shock The power jack and mating plug of the power cable meet IEC safety standards DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard KEEP AWAY FROM LIVE CIRCUITS Instrument covers must not be removed by operating personnel Component replacement and internal adjustments must be made by qualified maintenance personnel Disconnect the po
65. rotary input knob Valid storage buffer numbers range from I to 98 F4 CLEAR ALL Clears all data on all memory settings after a YES or NO selection message PERIOD 10 0000 pS ARE YOU SURE 3 6 6 UTIL Menu PERIOD 10 0000 pS Intensity 10 PIE ITEM Utility Menu F1 GPIB Selects the GPIB remote mode of operation After selection the GPIB can be set to any value from 1 to 31 using the rotary knob The value is kept in a nonvolatile memory and used at power on The factory default address is 10 Setting the address to 31 puts the device in the off bus state it will not respond to messages on the GPIB bus M4451 A00 29 Operating Manual SEFRAM 4451 PERIOD 10 0000 BS GPIB Address 8 GPIB Menu F2 RS232 Selects the RS232 remote control mode After selection the baud rate can be selected as 1200 2400 9600 19200 38400 57600 or 115K Always the RS 232 uses 8 bit data 1 stop bit and no parity F3 INTEN Selects the intensity of the LCD display Select a value using the rotary input knob Valid numeric values are from 1 to 31 The value is kept in the nonvolatile memory after a 20 seconds time out F4 POWER Power on default Selects the power on default setting Select a value using the data keys or the rotary input knob The selection is effective after a 20s time out period Select zero 0 to have the pulse generator power on with the factory default settings Select 99 to have
66. t 5 deviation from a straight line between 10 and 90 points for transitions gt 50 ns INTERNAL TRIGGER Range 100ns to 100s Resolution 4 digits limited 100ns Accuracy 0 01 INPUT AND OUTPUT TRIGGER INPUT Sensitivity 200 mVp p minimum Minimum Width 1005 Maximum Rate 50 Input Impedance 10 Input Protection 15V DC plus peak AC Range Selectable from 10V to 10V Resolution 3 digits limited to 10mV Slope Selection Positive or Negative SYNC OUTPUT A TTL level pulse at the programmed period Output impedance is 50 ohms protected against short circuit and up to 15V accidental input The high level is gt 2V into 50 ohms and with 3 5ns typical transition times M4451 A00 11 Operating Manual SEFRAM 4451 GPIB PROGRAMMING Internal 488 2 and SCPI compatible Address 0 30 front panel selected Subsets SHI L4 SRI RL1 PPO DC1 DT1 CO E2 GENERAL Memory Non volatile stores up to 99 complete panel settings Last user setup also retained at power down Power Requirements 100 240V 10 48 66 Hz 50VA maximum Dimensions Height 8 8cm Width 21 3 cm Length 30 cm Weight Aprox 3kg Net EMC According to EN55011 class B for radiated and conducted emissions Electrical Discharge Immunity According to EN55082 Safety Specifications According to EN61010 Operating Temperature 0 C to 50 C Storage Temperature 20 C to 60 C H
67. te query This query is used to read the value of the Status Byte COMMAND TYPE Common Query Syntax STB Response NRI The value of the Status Byte read with the STB query may differ from that read with the Serial Poll Bit 6 of the STB will be set as long as a reason for requesting service exists while bit 6 of the STB as read by the Serial Poll is cleared by the Serial Poll 4 11 5 Device Trigger Commands M4451 A00 TRG Trigger command This command is analogous to the IEEE 488 1 Group Execute Trigger interface message and has the same effect It is used to trigger the device to output a wave and is accepted only when the trigger mode is set to Trigger Gate or Burst and the trigger source is set to BUS Command Type Common Command 44 Operating Manual SEFRAM 4451 Syntax TRG 4 11 6 Stored Settings Commands 4 11 6 1 RCL Recall Instrument State This command is used to restore the state of the device to that stored in the specified memory location COMMAND TYPE Common Command Syntax RCL lt ws gt lt NRf gt Arguments Type lt NRf gt Range 0 to 99 Non integer values are rounded before execution Example RCL 0 Recall default state RCL 99 4 11 6 2 SAV Save Instrument State This command is used to store the current instrument state in the specified memory location COMMAND TYPE Common Command Syntax SAV lt ws gt lt NRf gt Arguments Type lt NRf gt Range 1 to 98 N
68. to 255 Non integer arguments are rounded before execution Examples ESE 48 Enables the CME and EXE bits ESE 255 Enables all standard events QUERY Syntax ESE Response NRI 4 11 4 3 ESR Standard Event Status Register Query This query is used to read the value of the Standard Event Status Register Reading the register clears it M4451 A00 43 Operating Manual SEFRAM 4451 COMMAND TYPE Command or Query Syntax ESR Response NRI 4 11 4 4 PSC Power On Status Clear Command This command is used to control the automatic power on clearing of certain status functions COMMAND TYPE Command or Query COMMON COMMAND Syntax PSC lt ws gt lt Boolean gt Arguments Type Boolean Examples PSC ON or PSC 1 PSC OFF or PSC 0 QUERY Syntax PSC Response ASCII 0 for OFF ASCII 1 for ON When set to ON 1 the Service Request Enable Register and the Standard Event Status Enable Register are cleared on power on 4 11 4 5 SRE Service Request Enable Command This command sets the Service Request Enable Register bits COMMAND TYPE Common Command or Query COMMON COMMAND Syntax SRE lt ws gt lt NRf gt Arguments Type NRf Range 0 to 255 Non integer arguments are rounded before execution The value of bit 6 is ignored and is set always to zero Examples SRE 48 Enables reporting of ESB and MAV events QUERY Syntax SRE Response NRI f STB Status by
69. umidity 90 RH at 0 C to 30 C CE Labeled NOTES Specifications are verified according to the Performance Check Procedure in this manual Specifications not qualified in this manual are either explanatory notes or general performance characteristics only M4451 A00 12 Operating Manual SEFRAM 4451 M4451 A00 13 Operating Manual SEFRAM 4451 2 1 2 2 2 3 2 4 2 5 Section 2 Installation Introduction This section contains installation information power requirements initial inspection and signal connections for the SEFRAM 4451 Initial Mechanical Inspection Upon receipt inspect the instrument for any damage that might have occurred in transit and verify the contents of the shipment accessories and installed options Initial Electrical Inspection The SEFRAM 4451 is calibrated and ready for use when received The Electrical Performance Check Procedure is detailed in Section 5 Instrument Mounting The SEFRAM 4451 50 MHz PROGRAMMABLE PULSE GENERATOR is intended for bench use The instrument includes a front feet tilt mechanism for optimum panel viewing angle The instrument does not require special cooling when operated within conventional temperature limits 5 cm minimum clearance must be provided at the rear of the unit for proper convection cooling The unit can be installed in a closed rack or test station if proper airflow is assured Power Requirements The SEFRAM 4451 can be operated from
70. wer cord before removing the instrument covers and replacing components Under certain conditions even with the power cable removed dangerous voltages may exist To avoid injuries always disconnect power and discharge circuits before touching them DO NOT SERVICE OR ADJUST ALONE Do not attempt any internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT SUBSTITUTE PARTS OR MODIFY THE INSTRUMENT Do not install substitute parts or perform any unauthorized modifications to this instrument Return the instrument to SEFRAM or any certified center for service and repair to ensure that safety features are maintained WARNINGS AND CAUTIONS WARNING and CAUTION statements such as the following examples denote a hazard and appear throughout this manual Follow all instructions contained in these statements A WARNING statement calls attention to an operating procedure practice or condition which if not followed correctly could result in injury or death to personnel A CAUTION statement calls attention to an operating procedure practice or condition which if not followed correctly could result in damage to or destruction of part or all of the product WARNING Do not alter the ground connection Without the protective ground connection all accessible conductive parts including control knobs can render an electric shock The power jack and mating plug of the power cabl
71. xternal trigger signal as the trigger source The trigger source is supplied through the TRIG IN connector F4 LEVEL SLOPE Two parameters are related to external trigger source operation These are LEVEL and SLOPE The Level determines at what voltage level the external signal will be recognized as a trigger At level less that this no pulse will be generated The Slope determines whether the positive or negative edge of the trigger signal will trigger the pulse 3 6 5 SETUPS Menu The pulse generator can store the current front panel settings called a setup into one of 99 storage buffers When you recall a setup the pulse generator restores the front panel settings to those that you stored in the selected buffer Because it is impossible to 100 guarantee against loss of stored data you should maintain a record of the data stored in memory so that you can manually restore such data if necessary M4451 A00 28 Operating Manual SEFRAM 4451 PERIOD 10 0000 pS Recall Default Set ic i a 7 SETUPS Menu F1 RECALL Recalls a previously stored front panel setup from the selected buffer Change the buffer number by using the rotary input knob Valid storage buffer numbers are from to 99 Buffer 0 is the factory default setup buffer 99 is the last front panel setup before power off F2 STORE Stores the current front panel setup to the specified storage buffer Change the buffer number by using the data keys or the

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