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Agilent 34401A 6.5 Digital Multimeter

1. Auto Man ENTER Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial 4 Move across to the BEEP command on the commands level There are eight command choices available in the SYS MENU Each choice on this level has a number prefix for easy identification 1 2 etc 5 Move down a level to the BEEP parameter choices The first parameter choice is ON for the BEEP command the beeper setting is stored in non volatile memory and ON is the factory setting N l 6 Move across to the OFF choice There are two parameter choices for BEEP OFF 7 Save the change and turn off the menu The multimeter beeps and displays a message to show that the change is now in effect You are then exited from the menu CHANGE SAVED 9 N Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial Menu Example 2 Recall Shift gt Auto Man ENTER The following exercise demonstrates how to use the menu recall feature as a shortcut to set the BEEP command back to its original setting You must perform the steps in Example 1 before you start this example 1 Use menu recall to return to the BEEP command This returns you to the BEEP command which was the last command used before you exited the menu in the Example 1 2 Move down to the BEEP parameter choices The first parameter
2. MINimum MAXimum MINimum MAXimum Default parameters are shown in bold DETector BANDwidth 3 20 200 MINimum MAXimum DETector BANDwidth 107 Chapter 4 Remote Interface Reference Command Summary Math Operation Commands see page 124 for more information CALCulate FUNCtion NULL DB DBM AVERage LIMit FUNCtion STATe OFF ON STATe CALCulate AVERage MINimum AVERage MAXimum AVERage AVERage AVERage COUNt CALCulate NULL OFFSet lt value gt MINimum MAXimum NULL OFFSet MINimum MAXimum CALCulate DB REFerence lt value gt MINimum MAXimum DB REFerence MINimum MAXimum CALCulate DBM REFerence lt value gt MINimum MAXimum DBM REFerence MINimum MAXimum CALCulate LIMit LOWer lt valwe gt MINimum MAXimum LIMit LOWer MINimum MAXimum LIMit UPPer lt valwe gt MINimum MAXimum LIMit UPPer MINimum MAXimum DATA FEED RDG_STORE CALCulate DATA FEED 108 Chapter 4 Remote Interface Reference Command Summary Triggering Commands see page 127 for more information INITiate READ TRIGger SOURce BUS IMMediate EXTernal SOURce TRIGger DELay lt seconds gt MINimum MAXimum DELay MINimum MAXimum TRIGger DELay AUTO OFF ON DELay AUTO SAMPle COUNt lt value gt MINimum MAXimum COUNt MINimum MAXimum TRIGger COUNt lt value gt MINimum MAXimum INFinite COUN
3. Connect the power cord and turn on the multimeter The front panel display will light up while the multimeter performs its power on self test The GPIB bus address is displayed Notice that the multimeter powers up in the dc voltage function with autoranging enabled To review the power on display with all annunciators turned on hold down Shift as you turn on the multimeter Perform a complete self test The complete self test performs a more extensive series of tests than those performed at power on Hold down Shift as you press the Power switch to turn on the multimeter hold down the key for more than 5 seconds The self test will begin when you release the key If the self test is successful PASS is displayed If the self test is not successful FAIL is displayed and the ERROR annunciator turns on See the Service Guide for instructions on returning the multimeter to Agilent for service 13 Chapter 1 Quick Start If the Multimeter Does Not Turn On If the Multimeter Does Not Turn On Use the following steps to help solve problems you might encounter when turning on the multimeter If you need more help see the Service Guide for instructions on returning the multimeter to Agilent for service 1 Verify that there is ac power to the multimeter First verify that the multimeter s Power switch is in the On position Also make sure that the power cord is firmly plugged into the power modu
4. To Check Diodes Test current source 1mA Maximum resolution 100 uV range is fixed at 1 Vdc Beeper threshold 0 3 volts lt Vineasureq lt 0 8 volts not adjustable Test Current Be NS ii 34401A YE Agilent 34421A annerer DAW Sonso input Ratio Ref vo ez t Ra ar x Forward Bias ee ee ig Del ACI aw Period dB ET dBm CO Power OV pk 3A vev acv az Freq US con f nun amp O Toit Soe odor GOO KO Recall car n 200v H HHH 19 Chapter 1 Quick Start To Select a Range To Select a Range You can let the multimeter automatically select the range using autoranging or you can select a fixed range using manual ranging Range 4 Digit 5 Digit 6 Digit Auto 3 v A ie Aaj 34401A Man tt Agilent i Digit Multimeter Selects a lower range and K K K K K K disables autoranging Selects a higher range and disables autoranging ging Man annunciator is on when manual range is enabled Toggles between autoranging and manual ranging e Autoranging is selected at power on and after a remote interface reset e Autorange thresholds Down range at lt 10 of range Up range at gt 120 of range e Ifthe input signal is greater than the present range can measure the multimeter will give an overload indication OVLD e For frequency and period measurements from the front pane
5. For this example single triggering is used to store readings You can also use auto triggering or reading hold Turn on the menu A MEAS MENU Move across to the SYS MENU choice on this level D SYS MENU Move down to a level to the RDGS STORE command 1 RDGS STORE aN 6 Chapter 2 Front Panel Menu Operation To Use Reading Memory vl gt 6 Move down a level and then across to the ON choice Auto Man 7 Save the change and exit the menu ENTER Notice that the Mem memory annunciator turns on to indicate that the multimeter is ready to store readings Up to 512 readings can be stored in first in first out FIFO order When memory is full the Mem annunciator will turn off Readings are preserved until you re enable reading memory at another time turn off the power or perform a remote interface reset Single Single 8 Trigger the multimeter three times Singl ange This stores three readings in memory Recall Shift gt 9 Use menu recall to retrieve the stored readings This takes you to the SAVED RDGS command in the SYS MENU 2 SAVED RDGS 47 Chapter 2 Front Panel Menu Operation To Use Reading Memory Lv 10 Move down a level to view the first stored reading Reading memory is automatically turned off when you go to the parameter level in the menu The first reading displayed is the first reading that was stored FIFO I
6. Re Ri Noise Caused by Magnetic Loops If you are making measurements near magnetic fields you should take the necessary precautions to avoid inducing voltages in the measurement connections You should be especially careful when working near conductors carrying large currents Use twisted pair connections to the multimeter to reduce the noise pickup loop area or dress the test leads as close together as possible Loose or vibrating test leads will also induce error voltages Make sure your test leads are tied down securely when operating near magnetic fields Whenever possible use magnetic shielding materials or physical separation to reduce problem magnetic field sources 201 Chapter 7 Measurement Tutorial Noise Caused by Ground Loops Noise Caused by Ground Loops When measuring voltages in circuits where the multimeter and the device under test are both referenced to a common earth ground a ground loop is formed As shown below any voltage difference between the two ground reference points Vground causes a current to flow through the measurement leads This causes errors such as noise and offset voltage usually power line related which are added to the measured voltage The best way to eliminate ground loops is to maintain the multimeter s isolation from earth do not connect the input terminals to ground If the multimeter must be earth referenced be sure to connect it and the device under tes
7. See four wire ohms 9 90000000E 37 61 131 A a d convertor 55 57 abort measurement 76 ac bandwidth detector 51 214 ac current connections 18 math functions allowed 63 124 ranges 18 signal filter 51 214 ac settling times 51 ac signal filter 51 214 ac voltage connections 17 loading errors 209 math functions allowed 63 124 ranges 17 signal filter 51 214 accessories included 13 222 accuracy highest 229 adapters RS 232 149 address GPIB 91 161 addressed commands IEEE 488 169 Agilent Express 6 alternate language compatibility Agilent 3478A 166 Fluke 8840A 8842A 167 annunciators 4 aperture time 58 automatic trigger delays 81 autoranging front panel key 20 threshold values 20 61 auto trigger 42 73 autozero definition 59 213 vs integration time 59 vs resolution 59 average min max measurements beeper control 88 description 39 64 front panel 39 functions allowed 63 124 B bandwidth detector 51 214 bandwidth error 208 baud rate 93 148 151 163 beeper continuity threshold 19 diode threshold 19 enable disable 88 BenchLink software 34812A 1 BNC connectors Ext Trig 5 83 VM Comp 5 83 boolean parameters 159 bumpers removing 23 burden voltage 205 212 bus triggering 75 127 C cables RS 232 150 CALCulate FUNCtion 63 124 CALCulate STATe 63 124 CALibration COUNt 98 146 CALibration SECure 97 146 CALibration STRing 99 147 cal
8. Shift lt ENTER Chapter 4 Remote Interface Reference To Set the GPIB Address To Set the GPIB Address Each device on the GPIB IEEE 488 interface must have a unique address You can set the multimeter s address to any value between 0 and 31 The address is set to 22 when the multimeter is shipped from the factory The address is displayed on the front panel when you turn on the multimeter See also GPIB Address on page 91 Turn on the front panel menu A MEAS MENU Move across to the I O MENU choice on this level E I O MENU Move down a level to the HP IB ADDR command 1 HP IB ADDR Move down to the parameter level to set the address Use the left right and down up arrow keys to change the address A22 ADDR Save the change and turn off the menu The address is stored in non volatile memory and does not change when power has been off or after a remote interface reset 161 On Off Shift lt Auto Man ENTER Chapter 4 Remote Interface Reference To Select the Remote Interface To Select the Remote Interface The multimeter is shipped with both an GPIB IEEE 488 interface and an RS 232 interface Only one interface can be enabled at a time The GPIB interface is selected when the multimeter is shipped from the factory See also Remote Interface Selection on page 92 1 Turn on the f
9. or 0 For a true condition the multimeter will accept ON or 1 When you query a boolean setting the instrument will always return 0 or 1 The following command uses a boolean parameter INPut IMPedance AUTO OFF ON String Parameters String parameters can contain virtually any set of ASCII characters A string must begin and end with matching quotes either with a single quote or with a double quote You can include the quote delimiter as part of the string by typing it twice without any characters in between The following command uses a string parameter DISPlay TEXT lt quoted string gt Output Data Formats Output data will be in one of formats shown in the table below Type of Output Data Output Data Format Non reading queries lt 80 ASCII character string Single reading IEEE 488 SD DDDDDDDDESDDenl gt Multiple readings IEEE 488 SD DDDDDDDDESDD lt nl gt Single reading RS 232 SD DDDDDDDDESDD lt lt cer gt lt nl gt Multiple readings RS 232 SD DDDDDDDDESDD lt cr gt lt nl gt S Negative sign or positive sign D Numeric digits E Exponent lt nl gt newline character lt cr gt _ carriage return character 159 Chapter 4 Remote Interface Reference Using Device Clear to Halt Measurements Using Device Clear to Halt Measurements Device clear is an IEEE 488 low level bus message which can be used to halt measurements in progress Different programmi
10. to separate multiple commands as shown below RST CLS ESE 32 OPC SCPI Parameter Types The SCPI language defines several different data formats to be used in program messages and response messages Numeric Parameters Commands that require numeric parameters will accept all commonly used decimal representations of numbers including optional signs decimal points and scientific notation Special values for numeric parameters like MINimum MAXimum and DEFault are also accepted You can also send engineering unit suffixes with numeric parameters e g M K or u If only specific numeric values are accepted the multimeter will automatically round the input numeric parameters The following command uses a numeric parameter VOLTage DC RANGe lt range gt MINimum MAXimum Discrete Parameters Discrete parameters are used to program settings that have a limited number of values like BUS IMMediate EXTernal They have a short form and a long form just like command keywords You can mix upper and lower case letters Query responses will always return the short form in all upper case letters The following command uses discrete parameters TRIGger SOURce BUS IMMediate EXTernal 158 Chapter 4 Remote Interface Reference Output Data Formats Boolean Parameters Boolean parameters represent a single binary condition that is either true or false For a false condition the multimeter will accept OFF
11. 0 0006 0 0005 0 0001 1000 000 V 0 0020 0 0006 0 0035 0 0010 0 0045 0 0010 0 0005 0 0001 Resistance 100 0000 Q 1 mA 0 0030 0 0030 0 008 0 004 0 010 0 004 0 0006 0 0005 4 1 000000 kQ 1 mA 0 0020 0 0005 0 008 0 001 0 010 0 001 0 0006 0 0001 10 00000 ka 100 uA 0 0020 0 0005 0 008 0 001 0 010 0 001 0 0006 0 0001 100 0000 kQ 10 uA 0 0020 0 0005 0 008 0 001 0 010 0 001 0 0006 0 0001 1 000000 MQ 5ynA 0 002 0 001 0 008 0 001 0 010 0 001 0 0010 0 0002 10 00000 MQ 500 nA 0 015 0 001 0 020 0 001 0 040 0 001 0 0030 0 0004 100 0000 MQ 500 nA 10 Ma 0 300 0 010 0 800 0 010 0 800 0 010 0 1500 0 0002 DC Current 10 00000 mA lt 0 1V 0 005 0 010 0 030 0 020 0 050 0 020 0 002 0 0020 100 0000 mA lt 0 6V 0 01 0 004 0 030 0 005 0 050 0 005 0 002 0 0005 1 000000 A lt 1V 0 05 0 006 0 080 0 010 0 100 0 010 0 005 0 0010 3 000000 A lt 2V 0 10 0 020 0 120 0 020 0 120 0 020 0 005 0 0020 Continuity 1000 0 Q 1mA 0 002 0 030 0 008 0 030 0 010 0 030 0 001 0 002 pigde Test 1 0000 V 1 mA 0 002 0 010 0 008 0 020 0 010 0 020 0 001 0 002 DC DC Ratio 100 mV Input Accuracy Reference Accuracy to 1000 V Input Accuracy accuracy specification for the HI LO input signal Reference Accuracy accuracy specification for the HI LO reference input signal Transfer Accuracy typical 24 hour of range error 2 Conditions Within 10 mi
12. 740 741 742 743 744 745 746 747 748 Chapter 5 Error Messages Calibration Errors 500V DC correction out of range Precharge DAC convergence failed A D turnover correction out of range AC flatness DAC convergence failed AC low frequency convergence failed AC low frequency correction out of range AC rms converter noise correction out of range AC rms 100th scale linearity correction out of range Cal checksum failed secure state Cal checksum failed string data Cal checksum failed DCV corrections Cal checksum failed DCI corrections Cal checksum failed RES corrections Cal checksum failed FRES corrections Cal checksum failed AC corrections Cal checksum failed GPIB address Cal checksum failed internal data 182 Application Programs Application Programs This chapter contains several remote interface application programs to help you develop programs for your measurement application Chapter 4 Remote Interface Reference starting on page 103 lists the syntax for the SCPI Standard Commands for Programmable Instruments commands available to program the multimeter The QuickBASIC example programs are written for the Agilent 82335A GPIB Interface Card and command library for IBM PC compatibles The GPIB IEEE 488 address is set to 22 when the multimeter is shipped from the factory The examples in this chapter assume an GPIB address of 22 When sending a remote interf
13. If the sample to sample levels are similar little settling time is required for each new reading Under this specialized condition the medium filter will provide reduced accuracy results at 5 readings per second and the fast filter will provide reduced accuracy results at 50 readings per second Additional settling time may be required when the dc level varies from sample to sample The multimeter s dc blocking circuitry has a settling time constant of 0 2 seconds This settling time only affects measurement accuracy when dc offset levels vary from sample to sample If maximum measurement speed is desired in a scanning system you may want to add an external dc blocking circuit to those channels with significant de voltages present This circuit can be as simple as a resistor and a capacitor 214 Specifications Chapter 8 Specifications DC Characteristics E DC Characteristics Accuracy Specifications of reading of range 1 Temperature Test Current or 24 Hour 2 90 Day 1 Year Coefficient C Function Range 3 Burden Voltage 230C 1 23 C 5 C 23 C 5 C 0 C 18 C 28 C 55 C DC Voltage 100 0000 mV 0 0030 0 0030 0 0040 0 0035 0 0050 0 0035 0 0005 0 0005 1 000000 V 0 0020 0 0006 0 0030 0 0007 0 0040 0 0007 0 0005 0 0001 10 00000 V 0 0015 0 0004 0 0020 0 0005 0 0035 0 0005 0 0005 0 0001 100 0000 V 0 0020 0 0006 0 0035 0 0006 0 0045
14. Self Test Errors starting on page 179 176 350 410 420 430 440 Chapter 5 Error Messages Execution Errors Too many errors The error queue is full because more than 20 errors have occurred No additional errors are stored until you remove errors from the queue The error queue is cleared when power has been off or after a CLS clear status command has been executed Query INTERRUPTED A command was received which sends data to the output buffer but the output buffer contained data from a previous command the previous data is not overwritten The output buffer is cleared when power has been off or after a RST reset command has been executed Query UNTERMINATED The multimeter was addressed to talk i e to send data over the interface but a command has not been received which sends data to the output buffer For example you may have executed a CONFigure command which does not generate data and then attempted an ENTER statement to read data from the remote interface Query DEADLOCKED A command was received which generates too much data to fit in the output buffer and the input buffer is also full Command execution continues but all data is lost Query UNTERMINATED after indefinite response The IDN command must be the last query command within a command string Example IDN SYST VERS 177 501 502 511 512 513 514 521 522 531 532 540 55
15. To Test Continuity on page 19 52 Chapter 3 Features and Functions Measurement Configuration DC Input Resistance Normally the multimeter s input resistance is fixed at 10 MQ for all dc voltage ranges to minimize noise pickup To reduce the effects of measurement loading errors you can set the input resistance to greater than 10 GQ for the 100 mVdc 1 Vdc and 10 Vdc ranges Applies to dc voltage measurements and is disabled for all other functions Input Resistance Input Resistance 100mV 1V 10V ranges 100V 1000V ranges Fixed Resistance ON default 10 MQ 10 MQ Fixed Resistance OFF gt 10 GQ 10 MQ e The input resistance setting is stored in volatile memory the multimeter selects 10 MQ for all de voltage ranges when power has been off or after a remote interface reset e Front Panel Operation Select from the menu the 10 MQ mode fixed resistance for all dc voltage ranges or the gt 10 GQ mode The default is 10 MQ 3 INPUT R MEAS MENU e Remote Interface Operation You can enable or disable the automatic input resistance mode With AUTO OFF default the input resistance is fixed at 10 MQ for all ranges With AUTO ON the input resistance is set to gt 10 GQ for the three lowest dc voltage ranges The CONFigure and MEASure commands automatically turn AUTO OFF INPut IMPedance AUTO OFF ON 53 Chapter 3 Features and Functions Measurement Configuration Resolution Resolution
16. starting on page 25 you may want to read it now Chapter 4 Remote Interface Reference starting on page 103 lists the syntax for the SCPI commands available to program the multimeter Throughout this manual the following conventions are used for SCPI command syntax for remote interface programming e Square brackets indicate optional keywords or parameters e Braces enclose parameters within a command string e Triangle brackets lt gt indicate that you must substitute a value for the enclosed parameter e A vertical bar separates multiple parameter choices 50 Chapter 3 Features and Functions Measurement Configuration Measurement Configuration This section contains information to help you configure the multimeter for making measurements You may never have to change any of the measurement parameters discussed here but they are provided to give you the flexibility you might need AC Signal Filter The multimeter uses three different ac filters which enable you to either optimize low frequency accuracy or achieve faster ac settling times The multimeter selects the slow medium or fast filter based on the input frequency that you specify Applies to ac voltage and ac current measurements only Input Frequency 3 Hz to 300 kHz 20 Hz to 300 kHz 200 Hz to 300 kHz AC Filter Selected Slow filter Medium filter default Fast filter Settling Time 7 seconds reading 1 readi
17. 045 23 mVDC This is the 100 mVdc range 4 digits are displayed 113 325 6 OHM This is the 100 ohm range 6 digits are displayed The resolution is stored in volatile memory the multimeter sets the resolution to 5 digits for all functions when power has been off or after a remote interface reset The resolution is fixed at 5 digits for continuity and diode tests For dc and resistance measurements changing the number of digits does more than just change the resolution of the multimeter It also changes the integration time which is the period the multimeter s analog to digital A D converter samples the input signal for a measurement See also Integration Time on page 57 For ac measurements the resolution is actually fixed at 61 digits If you select 41 digits or 5 digits the multimeter masks one or two digits The only way to control the reading rate for ac measurements is by setting a trigger delay see page 79 For ratio measurements the specified resolution applies to the signal connected to the Input terminals 55 Chapter 3 Features and Functions Measurement Configuration Resolution e Front Panel Operation Select either the slow or fast mode for each continued resolution setting The default mode is 5 digits slow 5 RESOLUTION MEAS MENU See also To Set the Resolution on page 21 e Remote Interface Operation You can set the resolution using the following command
18. 150 data format 159 handshake protocol DTR DSR 151 parity selection 93 164 pass fail outputs 70 150 pin definitions 150 selecting interface 92 162 TALK ONLY mode 91 160 serial poll 137 service request SRQ 69 137 settling delays 204 trigger 79 signal filter 51 214 single trigger 42 73 sliding shelf kit 24 slow ac filter 51 214 software bus triggering 75 127 specifications 215 standard event register bit definitions 140 clearing 141 status byte bit definitions 136 clearing 136 summary register 136 235 Index status register commands 144 description 134 diagram 135 enable register 134 event register 134 STB 138 145 stop bits 148 storing readings functions allowed 46 84 number of readings stored 84 retrieving readings 46 storing readings 46 string length calibration message 99 displayed message 87 error queue 85 identification string 89 string parameters 159 summary register clearing 136 definition 136 support shelf kit 24 syntax conventions 50 105 155 SYSTem BEEPer 88 133 SYSTem ERRor 85 133 T TALK ONLY mode 91 92 160 temperature coefficient 210 224 228 terminals Ext Trig 5 83 Front Rear switch 2 58 GPIB interface 5 query setting 58 RS 232 interface 5 VM Comp 5 83 terminators input message 157 236 test complete self test 13 86 power on self test 13 86 reading memory 84 86 self test errors 17
19. 67 dBm measurements description 41 68 front panel 41 functions allowed 63 124 resistance values 41 68 dc current connections 18 math functions allowed 63 124 measurement errors 205 ranges 18 dc input resistance 53 dc voltage connections 17 input resistance 53 loading errors 199 math functions allowed 63 124 ranges 17 dev dev ratio measurements connections 44 front panel 44 math functions allowed 63 124 selecting 45 Declaration of Conformity 237 delay settling 204 trigger 79 DETector BANDwidth 51 123 detector bandwidth 51 214 device clear 152 157 160 dielectric absorption 204 digits number of 54 226 dimensions product 223 discrete parameters 158 232 diode beeper control 88 beeper threshold 19 connections 19 current source 19 math functions allowed 63 124 display annunciators 4 comma separator 37 89 enable disable 87 formats 22 message 87 DISPlay TEXT 87 132 DISPlay TEXT CLEar 87 132 DTR DSR handshake 151 E enable register clearing 136 141 143 definition 134 error messages calibration errors 180 error queue 85 172 error string length 85 172 execution errors 173 self test errors 179 errors bandwidth 208 burden voltage 212 common mode 212 crest factor 207 224 leakage current 199 service request generation 69 137 temperature coefficient 224 test lead resistance 204 thermal EMF 198 EOI end or identify 157
20. 723 724 Chapter 5 Error Messages Calibration Errors Invalid secure code An invalid calibration security code was received when attempting to unsecure or secure the multimeter You must use the same security code to unsecure the multimeter as was used to secure it and vice versa The security code may contain up to 12 alphanumeric characters The first character must be a letter Secure code too long A security code was received which contained more than 12 characters Cal aborted A calibration in progress is aborted when you press any front panel key send a device clear or change the local remote state of the multimeter Cal value out of range The specified calibration value CALibrat ion VALue is invalid for the present function and range Cal signal measurement out of range The specified calibration value CALibrat ion VALue does not match the signal applied to the multimeter Cal signal frequency out of range The input signal frequency for an ac calibration does not match the required input frequency for calibration No cal for this function or range You cannot perform calibrations for ac current period continuity diode ratio or on the 100 MQ range Full scale correction out of range Cal DCV offset out of range Cal DCI offset out of range Cal RES offset out of range Cal FRES offset out of range Extended resistance self cal failed 181 725 730 731 732 733 734 735 736
21. TRIG MENU If an automatic trigger delay is enabled AUTO is displayed momentarily before the actual number of seconds is displayed AUTO 79 Chapter 3 Features and Functions Triggering Trigger Delay e Front Panel Operation continued continued To set the delay to 0 seconds select the parameter level of the TRIG DELAY command Move the flashing cursor to the units location on the right side of the display Press v until ZERO DELAY is reached then press Menu Enter ZERO DELAY To select the automatic trigger delay select the parameter level of the TRIG DELAY command Move the flashing cursor to the units location on the right side of the display Press lv until AUTO DELAY is reached then press Menu Enter AUTO DELAY Remote Interface Operation You can use the following command to set the trigger delay TRIGger DELay lt seconds gt MINimum MAXimum You can use the following command to set an automatic trigger delay TRIGger DELay AUTO OFF ON 80 Chapter 3 Features and Functions Triggering Automatic Trigger Delays If you do not specify a trigger delay the multimeter selects an automatic delay for you The delay is determined by function range integration time and ac filter setting DC Voltage and DC Current for all ranges Integration Time Trigger Delay NPLC gt 1 1 5 ms NPLC lt 1 1 0 ms e Resistance
22. and some parameters as a mixture of upper and lower case letters The upper case letters indicate the abbreviated spelling for the command For shorter program lines send the abbreviated form For better program readability send the long form For example in the above syntax statement VOLT and VOLTAGE are both acceptable forms You can use upper or lower case letters Therefore VOLTAGE volt and Volt are all acceptable Other forms such as VOL and VOLTAG will generate an error Braces enclose the parameter choices for a given command string The braces are not sent with the command string A vertical bar separates multiple parameter choices for a given command string Triangle brackets lt gt indicate that you must specify a value for the enclosed parameter For example the above syntax statement shows the range parameter enclosed in triangle brackets The brackets are not sent with the command string You must specify a value for the parameter such as VOLT DC RANG 10 Some parameters are enclosed in square brackets The brackets indicate that the parameter is optional and can be omitted The brackets are not sent with the command string If you do not specify a value for an optional parameter the multimeter chooses a default value 155 Chapter 4 Remote Interface Reference An Introduction to the SCPI Language Command Separators A colon is used to separate a command keyword from
23. loading errors ac volts 209 dc volts 53 199 lock link kit 24 M magnetic loops 201 maintenance 100 manual range 20 61 math operations description 63 124 functions allowed 63 124 MEASure 113 117 preset state 112 measurement band frequency 18 period 18 measurement errors 224 measurement function math combinations allowed 63 124 measurement range autoranging 20 61 front panel keys 20 overload 61 142 selecting 20 measurement ranges 2 wire ohms 17 4 wire ohms 17 ac current 18 ac volts 17 dc current 18 de volts 17 dev dev ratio 44 frequency 18 period 18 measurement resolution front panel keys 21 half digit 21 54 setting 21 power line cycles 54 vs autozero 59 vs integration time 54 measurement terminals Front Rear switch 2 58 query setting 58 measurement tutorial 197 medium ac filter 51 214 memory internal functions allowed 46 84 number of readings stored 84 retrieving readings 46 storing readings 46 233 Index menu examples 31 36 overview 3 messages displayed 30 quick reference 27 28 tree diagram 29 messages displayed front panel 87 menu 30 message terminators 157 min max measurements beeper control 88 description 39 63 front panel 39 functions allowed 63 124 noise ground loop 202 magnetic loops 201 power line voltage 200 noise pickup 53 199 noise rejection 21 57 200 no parity 93 normal mode rejection NMR
24. outportb INT_controller End_of_interrupt void send_ctlc void outportb MCR 0x8 delay 10 int_buf_count int_buf_ovfl 0 delay 20 outportb MCR 0x9 int_buf_in Non specific Enable hardware interrupts Read byte from UART int_buf Clear UART interrupt EOI De assert DTR Wait 10 mS for stray characters while inportb LSR amp 0x20 Wait on transmitter register outportb THR 0x3 Send C while inportb LSR amp 0x40 Wait for C to be sent int_buf_in int_buf_out int_buf Clear int_char_in buffer 20mS for 34401 to clean up Assert DTR 196 Measurement Tutorial Measurement Tutorial The Agilent 34401A is capable of making highly accurate measurements In order to achieve the greatest accuracy you must take the necessary steps to eliminate potential measurement errors This chapter describes common errors found in measurements and gives suggestions to help you avoid these errors Thermal EMF Errors Thermoelectric voltages are the most common source of error in low level dc voltage measurements Thermoelectric voltages are generated when you make circuit connections using dissimilar metals at different temperatures Each metal to metal junction forms a thermocouple which generates a voltage proportional to the junction temperature You should take th
25. you should use manual range to get to the lowest range possible for the measurement High Voltage Self Heating Errors If you apply more than 300 Vrms self heating will occur in the multimeter s internal signal conditioning components These errors are included in the multimeter s specifications Temperature changes inside the multimeter due to self heating may cause additional error on other ac voltage ranges The additional error will be less than 0 02 and will dissipate in a few minutes Temperature Coefficient and Overload Errors The Agilent 34401A uses an ac measurement technique that measures and removes internal offset voltages when you select a different function or range If you leave the multimeter in the same range for an extended period of time and the ambient temperature changes significantly or if the multimeter is not fully warmed up the internal offsets may change This temperature coefficient is typically 0 002 of range per C and is automatically removed when you change functions or ranges When manual ranging to a new range in an overload condition the internal offset measurement may be degraded for the selected range Typically an additional 0 01 of range error may be introduced This additional error is automatically removed when you remove the overload condition and then change functions or ranges 210 Chapter 7 Measurement Tutorial Low Level Measurement Errors Low Level Measurement Errors When
26. 0 011 0 005 50 kHz 100 kHz 0 55 0 08 0 60 0 08 0 60 0 08 0 060 0 008 100 kHz 300 kHz 6 4 00 0 50 4 00 0 50 4 00 0 50 0 20 0 02 1 000000 V 3Hz 5 Hz 1 00 0 02 1 00 0 03 1 00 0 03 0 100 0 003 to 5 Hz 10 Hz 0 35 0 02 0 35 0 03 0 35 0 03 0 035 0 003 750 000 V 10 Hz 20 kHz 0 04 0 02 0 05 0 03 0 06 0 03 0 005 0 003 20 kHz 50 kHz 0 10 0 04 0 11 0 05 0 12 0 05 0 011 0 005 50 kHz 100 kHz 5 0 55 0 08 0 60 0 08 0 60 0 08 0 060 0 008 100 kHz 300 kHz 6 4 00 0 50 4 00 0 50 4 00 0 50 0 20 0 02 True RMS 1 000000 A 3Hz 5 Hz 1 00 0 04 1 00 0 04 1 00 0 04 0 100 0 006 AC Current 5 Hz 10 Hz 0 30 0 04 0 30 0 04 0 30 0 04 0 035 0 006 4 10 Hz 5 kHz 0 10 0 04 0 10 0 04 0 10 0 04 0 015 0 006 3 00000 A 3Hz 5 Hz 1 10 0 06 1 10 0 06 1 10 0 06 0 100 0 006 5 Hz 10 Hz 0 35 0 06 0 35 0 06 0 35 0 06 0 035 0 006 10 Hz 5 kHz 0 15 0 06 0 15 0 06 0 15 0 06 0 015 0 006 Additional Low Frequency Errors of reading Additional Crest Factor Errors non sinewave 7 AC Filter o i Frequency Slow Medium Fast ve 2 ctor R f reading 10 Hz 20 Hz 0 0 74 2 3 0 15 20 Hz 40 Hz 0 0 22 3 4 0 30 40 Hz 100 Hz 0 0 06 0 73 4 5 0 40 100 Hz 200 Hz 0 0 01 0 22 200 Hz 1 kHz 0 0 0 18 gt 1 kHz 0 0 0 Sinewave Transfer Accuracy typical Frequency Error of range Conditions 10 Hz
27. 1 10 or 100 power line cycles The default is 10 PLCs The integration time is stored in volatile memory the multimeter selects 10 PLCs when power has been off or after a remote interface reset Only the integral number of power line cycles 1 10 or 100 PLCs provide normal mode line frequency noise rejection The only way to control the reading rate for ac measurements is by setting a trigger delay see page 79 The following table shows the relationship between integration time and measurement resolution Integration Time Resolution 0 02 NPLC 0 0001 x Full Scale 0 2 NPLC 0 00001 x Full Scale 1 NPLC 0 000003 x Full Scale 10 NPLC 0 000001 x Full Scale 100 NPLC 0 0000003 x Full Scale 57 Chapter 3 Features and Functions Measurement Configuration Integration Time e Front Panel Operation Integration time is set indirectly when you continued select the number of digits See the table for resolution on page 54 Remote Interface Operation lt function gt NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum For frequency and period measurements aperture time or gate time is analogous to integration time Specify 10 ms 4 digits 100 ms default 51 2 digits or 1 second 61 digits FREQuency APERture 0 01 0 1 1 MINimum MAXimum PERiod APERture 0 01 0 1 1 MINimum MAXimum Front Rear Input Terminal Switching Any measurement made using the front terminals can also be made us
28. 10 of range 1 sample Automatic Delay Auto Trigger Power On Reset State e On e On On Off cleared Power On Reset State e 9600 baud e 22 GPIB IEEE 488 e SCPI Even 7 data bits Power On Reset State e Secured 101 102 Remote Interface Reference Remote Interface Reference e Command Summary starting on page 105 e Simplified Programming Overview starting on page 112 e The MEASure and CONFigure Commands starting on page 117 e Measurement Configuration Commands starting on page 121 e Math Operation Commands starting on page 124 e Triggering starting on page 127 e Triggering Commands starting on page 130 e System Related Commands starting on page 132 e The SCPI Status Model starting on page 134 e Status Reporting Commands starting on page 144 e Calibration Commands on page 146 e RS 232 Interface Configuration starting on page 148 e RS 232 Interface Commands on page 153 e An Introduction to the SCPI Language starting on page 154 e Output Data Formats on page 159 e Using Device Clear to Halt Measurements on page 160 e TALK ONLY for Printers on page 160 e To Set the GPIB Address on page 161 e To Select the Remote Interface on page 162 e To Set the Baud Rate on page 163 e To Set the Parity on page 164 e To Select the Programming Language on page 165 e Alternate Programming Language Compatibility starting on page 166 e SCPI Compliance Information on page 1
29. 154 Chapter 4 Remote Interface Reference Triggering Triggering See also Triggering starting on page 71 in chapter 3 The multimeter s triggering system allows you to generate triggers either manually or automatically take multiple readings per trigger and insert a delay before each reading Normally the multimeter will take one reading each time it receives a trigger but you can specify multiple readings up to 50 000 per trigger Triggering the multimeter from the remote interface is a multi step process that offers triggering flexibility e First you must configure the multimeter for the measurement by selecting the function range resolution etc e Then you must specify the source from which the multimeter will accept the trigger The multimeter will accept a software bus trigger from the remote interface a hardware trigger from the rear panel Ext Trig external trigger terminal or an immediate internal trigger e Then you must make sure that the multimeter is ready to accept a trigger from the specified trigger source this is called the wait for trigger state The diagram on the next page shows the multimeter s triggering system 127 Chapter 4 Remote Interface Reference Triggering Agilent 34401A Triggering System Initiate Triggering MEASure READ INITiate ooo Wait for Trigger State Trigger Source TRIGger SOURce IMMediate TRIGger SOURce EXTernal TRIGger
30. 2 wire and 4 wire Trigger Delay Trigger Delay Range For NPLC gt 1 Range For NPLC lt 1 100 Q 1 5 ms 100 Q 1 0ms 1 ka 1 5ms 1 ka 1 0 ms 10 ka 1 5 ms 10 ka 1 0ms 100 ka 1 5 ms 100 ka 1 0 ms 1 MQ 15 ms 1 Mo 10 ms 10 Ma 100 ms 10 Ma 100 ms 100 Ma 100 ms 100 Ma 100 ms e AC Voltage and AC Current for all ranges Remote or single external trigger Front panel with auto trigger ON AC Filter Trigger Delay AC Filter Trigger Delay Slow 7 0 sec Slow 1 5 sec Medium 1 0 sec Medium 200 ms Fast 600 ms Fast 100 ms e Frequency and Period Remote or single external trigger Front panel with auto trigger ON Trigger Delay Trigger Delay 1 0 sec 0 sec 81 Chapter 3 Features and Functions Triggering Reading Hold The reading hold feature allows you to capture and hold a stable reading on the front panel display This is especially useful in situations where you want to take a reading remove the test probes and have the reading remain on the display When a stable reading is detected the multimeter emits a beep if the front panel beeper is enabled and holds the reading on the display See also Beeper Control on page 88 The reading hold feature is available only from the front panel If you go to remote when reading hold is enabled the multimeter ignores it when you return to local front panel reading hold is enabled again e Reading hold has an adjus
31. 50 kHz 0 002 Sinewave input 50 kHz 300 kHz 0 005 Within 10 minutes and 0 5 C 218 Within 10 of initial voltage and 1 of initial frequency Following a 2 hour warm up Fixed range between 10 and 100 of full scale and lt 120 V Using 612 digit resolution Measurements are made using accepted metrology practices Chapter 8 Specifications AC Characteristics Measuring Characteristics Measurement Noise Rejection 8 AC CMRR 70 dB True RMS AC Voltage Measurement Method AC coupled True RMS measures the ac component of input with up to 400 Vdc of bias on any range Crest Factor Maximum 5 1 at full scale AC Filter Bandwidth Slow 3 Hz 300 kHz Medium 20 Hz 300 kHz Fast 200 Hz 300 kHz Input Impedance Input Protection 1 MQ 2 in parallel with 100 pF 750 V rms all ranges Operating Characteristics 9 Function Digits Reading s ACV ACI 6 7 sec reading 6 1 6 1 6 10 6 10 6 50 11 AC Filter Slow Medium Fast Fast Fast True RMS AC Current Measurement Method Direct coupled to the fuse and shunt AC coupled True RMS measurement measures the ac component only 0 19 for 1 A and 3A ranges 1 A range lt 1Vrms 3 A range lt 2 Vrms Externally accessible 3A 250 V fuse Internal 7A 250 V fuse Shunt Resistor Burden Voltage Input Protection Settling Considerations Applying gt 300 V rms or gt 1 A rms will cause self heating in signal con
32. 57 200 NPLC 54 57 200 null measurements description 38 65 front panel 38 functions allowed 63 124 Null Register 38 66 null test lead resistance 38 65 204 number of digits 54 226 number of readings 77 numeric parameters 158 234 Oo odd parity 93 offset null measurements description 38 65 front panel 38 functions allowed 63 124 Null Register 38 66 null test lead resistance 38 65 204 offset voltages 59 196 ohms 2 wire connections 17 math functions allowed 63 124 ranges 17 4 wire connections 17 math functions allowed 63 124 ranges 17 OPC 137 operator maintenance 100 output data format 159 output buffer 139 overload 61 142 OVLD 61 142 P parameter types 158 parity 93 164 parts per million 227 pass fail limit test beeper control 88 description 69 functions allowed 63 124 RS 232 pass fail outputs 70 service request 69 142 PERiod APERture 58 122 period aperture time 58 connections 18 math functions allowed 63 124 measurement band 18 power cord 15 power dissipation effects 204 power line cycles 54 57 200 power line frequency power on sensing 200 power line fuse factory configuration 14 installation 15 power line noise rejecting 200 power line voltage factory setting 14 selector module 15 setting the 15 power on self test 13 sequence 13 state 101 product dimensions 223 product specifications 215 programming language c
33. GTL Go to Local LLO Local Lock Out SDC Selected Device Clear SPD Serial Poll Disable SPE Serial Poll Enable IEEE 488 2 Common Commands CLS RST ESE lt enable value gt SRE lt enable value gt ESE SRE ESR STB IDN TRG OPC TST OPC PSC 011 PSC 169 170 Error Messages Error Messages e Errors are retrieved in first in first out FIFO order The first error returned is the first error that was stored When you have read all errors from the queue the ERROR annunciator turns off The multimeter beeps once each time an error is generated e Ifmore than 20 errors have occurred the last error stored in the queue the most recent error is replaced with 350 Too many errors No additional errors are stored until you remove errors from the queue If no errors have occurred when you read the error queue the multimeter responds with 0 No error e The error queue is cleared when power has been off or after a CLS clear status command has been executed The RST reset command does not clear the error queue e Front Panel Operation 3 ERROR SYS MENU If the ERROR annunciator is on press Shift gt Recall Menu to read the errors stored in the queue The errors are listed horizontally on the parameter level All errors are cleared when you go to the parameter level and then turn off the menu ERR 1 113 First error in queue
34. INFO10 FO11S OPC E H11 LEN INFO11 FO12S CALC AVER AVER MIN MAX E H12 LEN INF012 FO13S CLS E H13 LEN INFO13 DIM A 1 3 Actual 0 Reading 0 Continued on next page gt 190 Chapter 6 Application Programs Using the Status Registers GPIB Operation Using QuickBASIC continued Call IOCLEAR DEV amp Call IOOUTPUTS DEV amp INFO1 LENGTH1 Call IOOUTPUTS DEV amp INFO2 LENGTH2 ON PEN GOSUB RESULTS PEN ON Call IOPEN ISC amp 0 Call IOOUTPUTS DEV amp INFO3 LENGTH3 Call IOOUTPUTS DEV amp INFO4 LENGTH43 Call IOOUTPUTS DEV amp INFO5 LENGTH5 Call IOE ER DEV amp Reading Call IOOUTPUTS DEV amp INFO6 LENGTH6 Call IOOUTPUTS DEV amp INFO7 LENGTH73 Call IOOUTPUTS DEV amp INFO8 LENGTH8 Call IOOUTPUTS DEV amp INFO9 LENGTH9 BACK GOTO BACK RESULTS Call IOOUTPUTS DEV amp INFO10S LENGTH10 Call IOOUTPUTS DEV amp INFO11 LENGTH11 Call IOOUTPUTS DEV amp INFO12 LENGTH12 D Call IOE ERA For I 1 to 3 EV amp Seg A 1 3 Actual s ext E Call IOOUTPUTS DEV amp INFO13 LENGTH13 END 191 Chapter 6 Application Programs RS 232 Operation Using QuickBASIC RS 232 Operation Using Quic
35. Naw Period gt dB dBm Power nev acv maw Frea cont nu Mn Max o O Range a Oy 1 4 Digit 5 Digit 6 Digit Auto Hold OOUR WME w On Off Recall Enter UHH Menu Local CAT 1 300v Range pip Auto 6 Auto lt gt M a R On Off Recall Enter Menu 1 Measurement Function keys 5 Front Rear Input Terminal Switch 2 Math Operation keys 6 Range Number of Digits Displayed keys 3 Single Trigger Autotrigger Reading Hold key 7 Menu Operation keys 4 Shift Local key The Front Panel Menu at a Glance The menu is organized in a top down tree structure with three levels To turn on menu press let or ght ipa con Onsort A MEAS MENU gt 8B MATH MENU gt C TRIG MENU gt D SYS MENU gt E 1 O MENU gt F CAL MENU 4 l l 4 4 4 L AC FLTER 2 contnuTy i mnax m e ReaD Hoo 7 t ROGS store t HPB ador i SecuRED To enter command press Autos Man Enter A MEASurement MENU 1 AC FILTER gt 2 CONTINUITY gt 3 INPUTR gt 4 RATIO FUNC gt 5 RESOLUTION B MATH MENU 1 MIN MAX gt 2 NULL VALUE gt 3 dB REL gt 4 dBm REFR gt 5 LIMIT TEST gt 6 HIGH LIMIT gt 7 LOW LIMIT C TRIGger MENU 1 READ HOLD gt 2 TRIG DELAY gt 3 N SAMPLES D SYStem MENU 1 RDGS STORE gt 2 SAVED RDGS gt 3 ERRO
36. Ref S m ayo Function Math Lo Lo DGI ACI naw Poriod dB dBm Power 500Vpk 3A v acv aw reJ leen eee E rime AC or DC Current A Digit 5 Digi 6 Digit Auto Hold mo lt gt v J l A Ga ISIOLO Front On Off Roc ria DCI ACI To Measure Frequency or Period Measurement band 3 Hz to 300 kHz 0 33 sec to 3 3 usec Input signal range 100 mVac to 750 Vac Technique reciprocal counting HE Aaltent 3440 inter M4W Sense Input A i va Or 200v pov Max Frequency or Period Function Math to Lo DCI ACI a4w Period all dB dBm Power 500p ocv facv azw Freq comm f nu Me eee OF A Digit 5 Digit 8 Digit Auto Hald On ott Recall Wna Enter CAT 11 300V A c 18 Chapter 1 Quick Start To Test Continuity To Test Continuity Test current source 1mA Maximum resolution 0 1 Q range is fixed at 1 kohm Beeper threshold 1Q to 1000Q beeps below adjustable threshold Test Current OY B4401A FE Agtiont 84401A motar RAW Sense Input A va Open or Closed Circuit Max 1 on Math Lo o e Lo pc acl ow Period dB dBm Power 500Vpk aA ov acv 2w a co nt nun M a Max wa Poit Bd 6Digt Ano Hold Orn 7 DOO wBe se On Off Recall Menu Entor Rear cari 300v AY
37. Service Not Used Serial Poll SPOLL SRE lt value gt STB SRE Output Buffer 135 Chapter 4 Remote Interface Reference The SCPI Status Model The Status Byte The status byte summary register reports conditions from other status registers Query data that is waiting in the multimeter s output buffer is immediately reported through the message available bit bit 4 Bits in the summary registers are not latched Clearing an event register will clear the corresponding bits in the status byte summary register Reading all messages in the output buffer including any pending queries will clear the message available bit Bit Definitions Status Byte Register Decimal Bit Value Definition 0 Not Used 1 Always set to 0 1 Not Used 2 Always set to 0 2 Not Used 4 Always set to 0 3 Questionable Data 8 One or more bits are set in the Questionable Data register bits must be enabled in enable register 4 Message Available 16 Data is available in the multimeter s output buffer 5 Standard Event 32 One or more bits are set in the Standard Event register bits must be enabled in enable register 6 Request Service 64 The multimeter is requesting service serial poll 7 Not Used 128 Always set to 0 The status byte summary register is cleared when e You execute a CLS clear status command e Querying the standard event and questionable data registers will clear only
38. Time 10 ms 100 ms or 1 sec Operating Characteristics 5 100 mV rms full scale to 750 V rms Settling Considerations Errors will occur when attempting to measure the frequency or period of an input following a dc offset voltage change The input blocking RC time constant must be allowed to fully settle up to 1 sec before the most accurate measurements are possible Measurement Considerations All frequency counters are susceptible to error when measuring low voltage low frequency signals Shielding inputs from external noise pickup is critical for minimizing measurement errors 221 Function Digits Reading s Frequency 6 1 Period 5 9 8 4 80 System Speeds 5 Configuration Rates 14 sec Autorange Time lt 0 6 sec ASCII readings to RS 232 55 sec ASCII readings to GPIB 80 sec Max Internal Trigger Rate 80 sec Max External Trigger Rate to Memory 80 sec Max External Trigger Rate to GPIB RS 232 80 sec 1 2 3 4 5 Specifications are for 1 hour warm up at 61 digits Relative to calibration standards 20 overrange on all ranges except 750 Vac range Input gt 100 mV For 10 mV to 100 mV inputs multiply of reading error x10 Speeds are for 41 digits Delay 0 Display OFF and Fast AC filter Chapter 8 Specifications General Information E General Information General Specifications Power Supply Power Line Frequency Power Consumption Operating Environment Storage Envi
39. X X X X X X X X X X X xX X X X X X X X X X X X X xX X CALCulate FUNCtion NULL DB DBM AVERage LIMit Select the math function Only one function can be enabled at a time The default function is null Stored in volatile memory CALCulate FUNCtion Query the present math function Returns NULL DB DBM AVER or LIM CALCulate STATe OFF ON Disable or enable the selected math function Stored in volatile memory CALCulate STATe Query the state of the math function Returns 0 OFF or 1 ON 124 Chapter 4 Remote Interface Reference Math Operation Commands CALCulate AVERage MINimum Read the minimum value found during a min max operation The multimeter clears the value when min max is turned on when power has been off or after a remote interface reset Stored in volatile memory CALCulate AVERage MAXimum Read the maximum value found during a min max operation The multimeter clears the value when min max is turned on when power has been off or after a remote interface reset Stored in volatile memory CALCulate AVERage AVERage Read the average of all readings taken since min max was enabled The multimeter clears the value when min max is turned on when power has been off or after a remote interface reset Stored in volatile memory CALCulate AVERage COUNt Read the number of readings taken since min max was enabled The multimeter clears the value when min max is
40. XX XX XX Remote Interface Operation IDN returns HEWLETT PACKARD 34401A 0 XX XX XX Be sure to dimension a string variable with at least 35 characters 89 Chapter 3 Features and Functions System Related Operations SCPI Language Version Query The multimeter complies with the rules and regulations of the present version of SCPI Standard Commands for Programmable Instruments You can determine the SCPI version with which the multimeter is in compliance by sending a command from the remote interface You cannot query the SCPI version from the front panel e The following command returns the SCPI version SYSTem VERSion Returns a string in the form YYYY V where the Y s represent the year of the version and the V represents a version number for that year for example 1991 0 90 Chapter 3 Features and Functions Remote Interface Configuration Remote Interface Configuration This section gives information on configuring the remote interface For additional information see chapter 4 Remote Interface Reference starting on page 103 GPIB Address Each device on the GPIB IEEE 488 interface must have a unique address You can set the multimeter s address to any value between 0 and 31 The address is set to 22 when the multimeter is shipped from the factory The GPIB address is displayed at power on The GPIB address can be set only from the front panel e The
41. a lower level keyword You must insert a blank space to separate a parameter from a command keyword If a command requires more than one parameter you must separate adjacent parameters using a comma as shown below CONF VOLT DC 10 0 003 A semicolon is used to separate commands within the same subsystem and can also minimize typing For example sending the following command string TRIG DELAY 1 COUNT 10 is the same as sending the following two commands TRIG DELAY 1 TRIG COUNT 10 Use a colon and a semicolon to link commands from different subsystems For example in the following command string an error is generated if you do not use both the colon and semicolon SAMP COUN 10 TRIG SOUR EXT Using the MIN and MAX Parameters You can substitute MINimum or MAXimum in place of a parameter for many commands For example consider the following command VOLTage DC RANGe lt range gt MINimum MAXimum Instead of selecting a specific voltage range you can substitute MIN to set the range to its minimum value or MAX to set the range to its maximum value 156 Caution Chapter 4 Remote Interface Reference An Introduction to the SCPI Language Querying Parameter Settings You can query the current value of most parameters by adding a question mark to the command For example the following command sets the sample count to 10 readings SAMP COUN 10 You can query the sample cou
42. a multimeter The number of digits is equal to the maximum number of 9 s the multimeter can measure or display This indicates the number of full digits Most multimeters have the ability to overrange and add a partial or 4 digit For example the Agilent 34401A can measure 9 99999 Vdc on the 10 V range This represents six full digits of resolution The multimeter can also overrange on the 10 V range and measure up to a maximum of 12 00000 Vdc This corresponds to a 6 2 digit measurement with 20 overrange capability Sensitivity Sensitivity is the minimum level that the multimeter can detect for a given measurement Sensitivity defines the ability of the multimeter to respond to small changes in the input level For example suppose you are monitoring a 1 mVdc signal and you want to adjust the level to within 1 uV To be able to respond to an adjustment this small this measurement would require a multimeter with a sensitivity of at least 1 uV You could use a 64 digit multimeter if it has a 1 Vdc or smaller range You could also use a 4 digit multimeter with a 10 mVdc range For ac voltage and ac current measurements note that the smallest value that can be measured is different from the sensitivity For the Agilent 34401A these functions are specified to measure down to 1 of the selected range For example the multimeter can measure down to 1 mV on the 100 mV range 226 Chapter 8 Specifications Interpreting Multi
43. and fuse A second fuse is located inside the multimeter to provide an additional level of current protection This fuse is a 7A 250 Vac high interrupt rated fuse Agilent part number 2110 0614 To replace this fuse you must remove the multimeter s case by loosening three screws See the Service Guide for more information on disassembling the multimeter 100 Chapter 3 Features and Functions Power On and Reset State Power On and Reset State The parameters marked with a bullet e are stored in non volatile memory The factory settings are shown For your convenience this table is duplicated on the rear cover of this manual and on the Quick Reference Card Measurement Configuration AC Filter Autozero e Continuity Threshold Function Input Resistance Integration Time Range Resolution Math Operations Math State Function Math Registers e dBm Reference Resistance Triggering Operations Reading Hold Threshold Samples Per Trigger Trigger Delay Trigger Source System Related Operations Beeper Mode e Comma Separators Display Mode Reading Memory Input Output Baud Rate GPIB Address Interface Language Parity Configuration Calibration e Calibration State Power On Reset State 20 Hz medium filter On e 109 DC volts 10 MQ fixed for all dev ranges 10 PLCs Autorange 51 digits slow mode Power On Reset State Off Null All registers are cleared e 6002 Power On Reset State 0
44. and the input signal Result reading null value ERE SIN UNE EY SINE Enab To read edit the null value use the MATH menu 7 H 34401A ye Agilent 61 2 Digit Multimet r Math les null operation Math annunciator is on when Press again to disable null operation is enabled 38 You can make null measurements with any function except continuity diode or ratio The null operation is local to the selected function when you change functions null is disabled To null the test lead resistance for more accurate two wire ohms measurements short the ends of the test leads together and then press Null The first reading taken after you press Null is stored as the null value in the Null Register Any previously stored value is replaced with the new value After enabling null you can edit the stored null value by pressing Shift gt Menu Recall This takes you to the NULL VALUE command in the MATH MENU only if null is enabled Go down to the parameter level and then edit the displayed value The null register is cleared when you change functions turn null off turn off the power or perform a remote interface reset Chapter 2 Front Panel Menu Operation To Store Minimum and Maximum Readings To Store Minimum and Maximum Readings You can store the minimum and maximum readings during a series of measurements The following discussion shows how to read the
45. between 0 33 seconds and 3 3 usec With no input signal applied period measurements return 0 MEASure CONTinuity Preset and make a continuity measurement The reading is sent to the output buffer The range and resolution are fixed for continuity tests 1 kQ range and 51 2 digits MEASure DIODe Preset and make a diode measurement The reading is sent to the output buffer The range and resolution are fixed for diode tests 1 Vdc range with 1 mA current source output and 5 digits 118 Chapter 4 Remote Interface Reference The MEASure and CONFigure Commands CONFigure VOLTage DC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for dc voltage measurements with the specified range and resolution This command does not initiate the measurement CONFigure VOLTage DC RATio lt unge gt MIN MAX DEF lt esolution gt MIN MAX DEF Preset and configure the multimeter for dc dc ratio measurements with the specified range and resolution This command does not initiate the measurement For ratio measurements the specified range applies to the signal connected to the Input terminals Autoranging is automatically selected for reference voltage measurements on the Sense terminals CONFigure VOLTage AC lt unge gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for ac voltage measurements with the specified range and resolution This co
46. called null modem modem eliminator or crossover cables The interface cable must also have the proper connector on each end and the internal wiring must be correct Connectors typically have 9 pins DB 9 connector or 25 pins DB 25 connector with a male or female pin configuration A male connector has pins inside the connector shell and a female connector has holes inside the connector shell If you cannot find the correct cable for your configuration you may have to use a wiring adapter If you are using a DTE to DTE cable make sure the adapter is a straight through type Typical adapters include gender changers null modem adapters and DB 9 to DB 25 adapters Refer to the cable and adapter diagrams on the following page to connect the multimeter to most computers or terminals If your configuration is different than those described order the Agilent 34399A Adapter Kit This kit contains adapters for connection to other computers terminals and modems Instructions and pin diagrams are included with the adapter kit 149 Chapter 4 Remote Interface Reference RS 232 Interface Configuration DB 9 Serial Connection If your computer or terminal has a 9 pin serial port with a male connector use the null modem cable included with the Agilent 34398A Cable Kit This cable has a 9 pin female connector on each end The cable pin diagram is shown below F1047 80002 Cable PC Instrument DCD 1 1 D
47. choice is OFF the current setting from Example 1 OFF 3 Move across to the ON choice Set the parameter back to its original value N l 4 Save the change and turn off the menu The multimeter beeps and displays a message to show that the change is now in effect You are then exited from the menu CHANGE SAVED 33 Menu Example 3 On Off Shift lt Chapter 2 Fron t Panel Menu Operation A Front Panel Menu Tutorial Some commands in the menu require that you enter a numeric parameter value The following steps show you how to enter a number in the menu For this example you will set the null value to 2 0 volts Make sure the multimeter is in the dc voltage function with 51 2 digits of resolution displayed Disconnect all inputs to the multimeter 1 Turn on the menu You enter the menu on the menus level The MEAS MENU is your first choice on this level A MEAS M ENU 2 Move across to the MATH MENU choice on this level There are six menu group choices available on this level B MATH MI ENU 3 Move down to the commands level within the MATH MENU The MIN MAX command is your first choice on this level 1 MIN MAX 4 Move across to the NULL VALUE command on this level There are seven command choices available within the MATH MENU 2 NULL VALUE ew R Chapter 2 Front Panel Menu Operation A F
48. even parity 93 event register clearing 141 143 definition 134 examples CONFigure 116 front panel menu 31 36 MEASure 115 Ext Trig terminal 5 83 external trigger 42 74 83 F fast ac filter 51 214 FETCh 115 132 filler panel kit 24 filter ac signal 51 214 firmware revision query 89 fixed range 61 fixed input resistance 53 flange kit 24 flowchart triggering 72 Fluke 8840A 8842A compatibility 167 format output data 159 four wire ohms connections 17 math functions allowed 63 124 ranges 17 FREQuency APERture 58 122 frequency aperture time 58 connections 18 math functions allowed 63 124 measurement band 18 front panel annunciators 4 beeper 88 comma separator 37 89 display formats 22 enable disable 87 menu examples 31 36 messages displayed 30 overview 3 quick reference 27 28 tree diagram 29 messages front panel 87 front panel keys menu 29 range 20 resolution 21 trigger 42 Front Rear switch 2 58 fuses current input 5 100 power line 14 100 fuse holder assembly 5 15 Index G gate time 58 GPIB IEEE 488 address displayed at power on 13 factory setting 91 setting the 91 161 TALK ONLY mode 91 160 compliance information 168 connector location 5 selecting interface 92 162 ground chassis 5 ground loop noise 202 Group Execute Trigger GET 75 H half digit 21 54 hardware lines IEEE 488 169 handle adjusting 16 rem
49. following errors indicate failures that may occur during a self test Refer to the Service Guide for more information Front panel does not respond RAM read write failed A D sync stuck A D slope convergence failed Cannot calibrate rundown gain Rundown gain out of range Rundown too noisy Serial configuration readback failed DC gain x1 failed DC gain x10 failed DC gain x100 failed Ohms 500 nA source failed Ohms 5 uA source failed DC 1000V zero failed Ohms 10 uA source failed 179 616 617 618 619 620 621 622 623 624 625 626 701 702 Chapter 5 Error Messages Calibration Errors DC current sense failed Ohms 100 uA source failed DC high voltage attenuator failed Ohms 1 mA source failed AC rms zero failed AC rms full scale failed Frequency counter failed Cannot calibrate precharge Unable to sense line frequency I O processor does not respond 1 O processor failed self test Calibration Errors The following errors indicate failures that may occur during a calibration Refer to the Service Guide for more information Cal security disabled by jumper The calibration security feature has been disabled with a jumper inside the multimeter When applicable this error will occur at power on to warn you that the multimeter is unsecured Cal secured The multimeter is secured against calibration 180 703 704 705 706 707 708 709 710 720 721 722
50. interface the math operations and registers are controlled using commands within the CALCulate command subsystem First select the math operation you want to use the default function is null CALCulate FUNCtion NULL DB DBM AVERage LIMit Then enable the selected math function by turning the math state on CALCulate STATe ON 63 Chapter 3 Features and Functions Math Operations Min Max Operation The min max operation stores the minimum and maximum readings during a series of measurements The multimeter then calculates the average of all readings and records the number of readings taken since min max was enabled Applies to all measurement functions except continuity and diode e After you enable min max the first reading that the multimeter takes is stored as both the minimum and maximum value The minimum is replaced with any subsequent value that is less The maximum is replaced with any subsequent value that is greater e The multimeter displays MIN or MAX and beeps if the front panel beeper is enabled whenever a new minimum or maximum is found It is possible that the multimeter will beep even if the displayed reading does not change this is because the multimeter s internal resolution may be greater than the displayed resolution See also Beeper Control on page 88 e The minimum maximum average and count are stored in volatile memory the multimeter clears the values when min max is tu
51. is expressed in terms of number of digits the multimeter can measure or display You can set the resolution to 4 5 or 6 full digits plus a digit which can only be a 0 or 1 To increase measurement accuracy and improve noise rejection select 61 digits To increase measurement speed select 4 digits Applies to all measurement functions The resolution for the math operations null min max dB dBm limit test is the same as the resolution for the measurement function in use The correspondence between the number of digits selected and the resulting integration time in power line cycles is shown below The autozero mode is set indirectly when you set the resolution See also Autozero on page 59 Resolution Choices Integration Time Fast 4 Digit 0 02 PLC Slow 4 Digit 1 PLC Fast 5 Digit 0 2 PLC Slow 5 Digit default 10 PLC Fast 6 Digit 10 PLC Slow 6 Digit 100 PLC These settings configure the multimeter just as if you had pressed the corresponding DIGITS keys from the front panel Resolution is local to the selected function This means that you can select the resolution for each function independently The multimeter remembers the resolution when you switch between functions 54 Chapter 3 Features and Functions Measurement Configuration 5 digits 10 216 5 VDC Yo digit This is the 10 Vdc range 512 digits are displayed Yo digit
52. liable for errors or for incidental or consequential damages in connec tion with the furnishing use or per formance of this document or of any information contained herein Should Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms the warranty terms in the sep arate agreement shall control Technology Licenses The hardware and or software described in this document are furnished under a license and may be used or copied only in accor dance with the terms of such license Restricted Rights Legend U S Government Restricted Rights Soft ware and technical data rights granted to the federal government include only those rights customarily provided to end user cus tomers Agilent provides this customary commercial license in Software and techni cal data pursuant to FAR 12 211 Technical Data and 12 212 Computer Software and for the Department of Defense DFARS 252 227 7015 Technical Data Commercial Items and DFARS 227 7202 3 Rights in Commercial Computer Software or Com puter Software Documentation Safety Notices CAUTION A CAUTION notice denotes a haz ard It calls attention to an operat ing procedure practice or the like that if not correctly performed or adhered to could result in damage to the product or loss of important data Do not proceed beyond a CAUTION notice until the indicated conditions are fu
53. minimum maximum average and reading count To read the minimum maximum average and count use the MATH menu 61 2 Digit Multimeter ERE IK IS INU EN K K IK Math de Agilent 344014 z Enables min max operation Press again to disable Math annunciator is on when min max operation is enabled e You can use min max with any function except continuity or diode test The min max operation is local to the selected function when you change functions min max is disabled e After enabling min max you can read the stored minimum maximum average and count by pressing Shift gt Menu Recall This takes you to the MIN MAX command in the MATH MENU only if min max is enabled Go down to the parameter level and then read the values by pressing lt or gt e The stored values are cleared when you turn min max off turn off the power or perform a remote interface reset e The average is of all readings taken since min max was enabled not just the average of the stored minimum and maximum The count is the total number of readings taken since min max was enabled 39 Chapter 2 Front Panel Menu Operation To Make dB Measurements To Make dB Measurements Each dB measurement is the difference between the input signal and a stored relative value with both values converted to dBm dB reading in dBm relative value in dBm To read edit the dB relative v
54. multiple readings up to 50 000 per trigger You can trigger the multimeter from the front panel using a single trigger an external trigger or auto triggering Single triggering takes one reading each time you press the Single key External triggering is like single triggering but the multimeter waits for a pulse on the rear panel Ext Trig external trigger terminal before taking a reading Auto triggering takes continuous readings at the fastest rate possible for the present configuration See also To Trigger the Multimeter on page 42 Triggering the multimeter from the remote interface is a multi step process that offers triggering flexibility e First you must configure the multimeter for the measurement by selecting the function range resolution etc e Then you must specify the source from which the multimeter will accept the trigger The multimeter will accept a software bus trigger from the remote interface a hardware trigger from the Ext Trig terminal or an immediate internal trigger e Then you must make sure that the multimeter is ready to accept a trigger from the specified trigger source this is called the wait for trigger state The diagram on the next page shows the multimeter s triggering system 71 Chapter 3 Features and Functions Triggering Agilent 34401A Triggering System Initiate Triggering MEASure READ INITiate ooo Wait for Trigger State Trigg
55. power has been off or after a remote interface reset The CONFigure and MEASure commands automatically set the trigger count to 1 e Remote Interface Operation TRIGger COUNt lt value gt MINimum MAXimum INFinite 78 Chapter 3 Features and Functions Triggering Trigger Delay You can insert a delay between the trigger signal and each sample that follows This may be useful in applications where you want to allow the input to settle before taking a reading or for pacing a burst of readings If you do not specify a trigger delay the multimeter automatically selects a delay for you Delay range 0 to 3600 seconds The default trigger delay is automatic the delay is determined by function range integration time and ac filter setting see also Automatic Trigger Delays on page 81 The trigger delay is stored in volatile memory the multimeter selects an automatic trigger delay when power has been off or after a remote interface reset The CONFigure and MEASure commands automatically set the trigger delay to automatic If you specify a delay other than automatic that same delay is used for all functions and ranges If you have configured the multimeter to take more than one reading per trigger sample count gt 1 the specified trigger delay is inserted between the trigger and each reading Front Panel Operation You can use an automatic trigger delay or you can specify a delay in seconds 2 TRIG DELAY
56. resolution gt MIN MAX DEF lt function gt RANGe lt range gt MINimum MAXimum lt function gt RANGe AUTO OFF ON Chapter 3 Features and Functions Math Operations Math Operations There are five math operations available only one of which can be enabled at a time Each math operation performs a mathematical operation on each reading or stores data on a series of readings The selected math operation remains in effect until you disable it change functions turn off the power or perform a remote interface reset The math operations use one or more internal registers You can preset the values in some of the registers while others hold the results of the math operation The following table shows the math measurement function combinations allowed Each X indicates an allowable combination If you choose a math operation that is not allowed with the present measurement function math is turned off If you select a valid math operation and then change to one that is invalid a Settings conflict error is generated from the remote interface Null Min Max dB dBm Limit DCV ACV DCI ACI Q2W Q4W Freq Per Con Diode Ratio X X X X X X X X X X X X xX xX X xX X X X X X X X X X xX xX X X X From the front panel you enable a math operation by pressing the appropriate key The exception is Limit Test which you enable using the LIMIT TEST command in the MATH MENU From the remote
57. selection 92 162 replacing fuses 100 reset state 101 resistance 2 wire connections 17 math functions allowed 63 124 ranges 17 4 wire connections 17 math functions allowed 63 124 ranges 17 resistance input 53 resolution front panel keys 21 half digit 21 54 power line cycles 54 setting 21 vs autozero 59 vs integration time 54 retrieving stored readings 46 revision query firmware 89 ROUTe TERMinals 58 123 RS 232 interface baud rate selection 93 148 163 cables recommended 150 commands 153 connector location 5 150 connector pinout 150 data format 159 handshake protocol DTR DSR 151 parity selection 93 164 pass fail outputs 70 150 pin definitions 150 selecting interface 92 162 TALK ONLY mode 91 160 rubber bumpers removing 23 S SAMPle COUNt 77 131 samples number of 77 SCPI command summary 105 111 compliance information 168 data types 158 language introduction 154 status model 134 syntax conventions 50 105 155 version query 90 133 security code calibration changing 98 factory setting 95 rules 95 string length 95 self heating errors 210 self test complete test 13 86 errors 179 reading memory 84 86 power on test 13 86 sensitivity 226 sensitivity band reading hold 43 82 serial interface RS 232 baud rate selection 93 148 163 cables recommended 95 150 commands 153 connector location 5 150 connector pinout
58. situation that is prone to this error 211 Chapter 7 Measurement Tutorial Common Mode Errors Common Mode Errors Errors are generated when the multimeter s input LO terminal is driven with an ac voltage relative to earth The most common situation where unnecessary common mode voltages are created is when the output of an ac calibrator is connected to the multimeter backwards Ideally a multimeter reads the same regardless of how the source is connected Both source and multimeter effects can degrade this ideal situation Because of the capacitance between the input LO terminal and earth approximately 200 pF for the Agilent 34401A the source will experience different loading depending on how the input is applied The magnitude of the error is dependent upon the source s response to this loading The multimeter s measurement circuitry while extensively shielded responds differently in the backward input case due to slight differences in stray capacitance to earth The multimeter s errors are greatest for high voltage high frequency inputs Typically the multimeter will exhibit about 0 06 additional error for a 100 V 100 kHz reverse input You can use the grounding techniques described for dc common mode problems to minimize ac common mode voltages see page 201 AC Current Measurement Errors Burden voltage errors which apply to dc current also apply to ac current measurements However the burden voltage fo
59. the idle state to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied after the INITiate command is received The readings are placed in the multimeter s internal memory up to 512 readings can be stored Readings are stored in memory until you are able to retrieve them Use the FETCh command to retrieve reading results A new command is available starting with firmware Revision 2 which allows you to take readings using INITiate without storing them in internal memory This command may be useful with the min max operation since it allows you to determine the average of a series of readings without storing the individual values DATA FEED RDG_STORE do not store readings DATA FEED RDG_STORE CALCulate store readings default See page 126 for more information on using the DATA FEED command READ Change the state of the trigger system from the idle state to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied following the receipt of the READ command Readings are sent immediately to the output buffer TRIGger SOURce BUS IMMediate EXTernal Select the source from which the multimeter will accept a trigger The multimeter will accept a software bus trigger an immediate internal trigger this is the default source or a hardware trigger from the re
60. the best resolution MAX selects the largest value accepted which gives the least resolution DEF selects the default resolution which is 5 digits slow 10 PLC Note You must specify a rangeto use the resolution parameter MEASure VOLTage DC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make a dc voltage measurement with the specified range and resolution The reading is sent to the output buffer MEASure VOLTage DC RATio lt unge gt MIN MAX DEF lt resolution gt MIN MAX DEE Preset and make a de dc ratio measurement with the specified range and resolution The reading is sent to the output buffer For ratio measurements the specified range applies to the signal connected to the Input terminals Autoranging is automatically selected for reference voltage measurements on the Sense terminals MEASure VOLTage AC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make an ac voltage measurement with the specified range and resolution The reading is sent to the output buffer For ac measurements resolution is actually fixed at 61 digits The resolution parameter only affects the front panel display MEASure CURRent DC lt range gt MIN MAX DEF lt vesolution gt MIN MAX DEF Preset and make a dc current measurement with the specified range and resolution The reading is sent to the output buffer 117 Chapter 4 Remote Interface Reference Th
61. the command is executed OPC Returns 1 to the output buffer after the command is executed PSC 011 Power on status clear Clear the Status Byte and Standard Event register enable masks when power is turned on PSC 1 When PSC 0 is in effect the Status Byte and Standard Event register enable masks are not cleared when power is turned on Stored in non volatile memory PSC Query the power on status clear setting Returns 0 PSC 0 or 1 PSC 1 SRE lt enable value gt Enable bits in the Status Byte enable register SRE Query the Status Byte enable register The multimeter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register STB Query the Status Byte summary register The STB command is similar to a serial poll but it is processed like any other instrument command The STB command returns the same result as a serial poll but the request service bit bit 6 is not cleared if a serial poll has occurred 145 Chapter 4 Remote Interface Reference Calibration Commands Calibration Commands See Calibration Overview starting on page 95 for an overview of the calibration features of the multimeter For a more detailed discussion of the calibration procedures see chapter 4 in the Service Guide CALibration Perform a calibration using the specified calibration value CALibration VALue command Before you can calibrate the mu
62. the key for more than 5 seconds The self test will begin when you release the key Remote Interface Operation a TSA Returns 0 if the self test is successful or 1 if it fails Chapter 3 Features and Functions System Related Operations Display Control To speed up your measurement rate or for security reasons you may want to turn off the front panel display From the remote interface you can also display a 12 character message on the front panel e When the display is turned off readings are not sent to the display and all display annunciators except ERROR and Shift are disabled Front panel operation is otherwise unaffected by turning off the display e The display state is stored in volatile memory the display is enabled when power has been off or after a remote interface reset e You can display a message on the front panel by sending a command from the remote interface The multimeter can display up to 12 characters of the message on the front panel any additional characters are truncated Commas periods and semicolons share a display space with the preceding character and are not considered individual characters When a message is displayed readings are not sent to the display e Sending a message to the display from the remote interface overrides the display state this means that you can display a message even if the display is turned off e Front Panel Operation 5 DISPLAY SYS MENU The di
63. these errors and their harmonics will average out to approximately zero The Agilent 34401A provides three A D integration times to reject power line frequency noise and power line frequency harmonics When you apply power to the multimeter it measures the power line frequency 50 Hz or 60 Hz and then determines the proper integration time The table below shows the noise rejection achieved with various configurations For better resolution and increased noise rejection select a longer integration time Integration Time Digits NPLCs 60 Hz 50 Hz NMR 412 Fast 0 02 400 us 400 us 4 Slow 1 16 7ms 20 ms 60 dB 5 Fast 0 2 3ms 3 ms 5 Slow 10 167 ms 200 ms 60 dB 612 Fast 10 167 ms 200 ms 60 dB 612 Slow 100 1 67 sec 2 sec 60 dB 200 Chapter 7 Measurement Tutorial Common Mode Rejection CMR Common Mode Rejection CMR Ideally a multimeter is completely isolated from earth referenced circuits However there is finite resistance between the multimeter s input LO terminal and earth ground as shown below This can cause errors when measuring low voltages which are floating relative to earth ground I Vt float voltage pans aaa heal Rs DUT source resistance Viest Mesi imbalance T f 1 Ri multimeter isolation Rs i resistance LO Earth t A Oo O i Ci multimeter input capacitance 200 pF LO Earth at aie y aE Ci Ri gt 10 Ga ok o i fX Ws Error v
64. voltage mains connections meeting both of the following conditions The HI and LO input terminals are con nected to the mains under Measurement Category Il conditions defined below and The mains are limited to a maximum line voltage of 300 VAC 34401A User s Guide IEC Measurement Category II includes elec trical devices connected to mains at an out let on a branch circuit Such devices include most small appliances test equipment and other devices that plug into a branch outlet or socket The 34401A may be used to make measurements with the HI and LO inputs connected to mains in such devices or to the branch outlet itself up to 300 VAC However the 34401A may not be used with its HI and LO inputs connected to mains in permanently installed electrical devices such as the main circuit breaker panel sub panel disconnect boxes or permanently wired motors Such devices and circuits are subject to overvoltages that may exceed the protection limits of the 34401A Note Voltages above 300 VAC may be mea sured only in circuits that are isolated from mains However transient overvoltages are also present on circuits that are isolated from mains The Agilent 34401A are designed to safely withstand occasional transient overvoltages up to 2500 Vpk Do not use this equipment to measure circuits where transient overvoltages could exceed this level 34401A User s Guide Additional Notices Waste Electrical and Electronic
65. 0 Chapter 5 Error Messages Execution Errors Isolator UART framing error Isolator UART overrun error RS 232 framing error RS 232 overrun error RS 232 parity error Command allowed only with RS 232 There are three commands which are only allowed with the RS 232 interface SYSTem LOCal SYSTem REMote and SYSTem RWLock Input buffer overflow Output buffer overflow Insufficient memory There is not enough memory to store the requested number of readings in internal memory using the INITiate command The product of the sample count SAMP le COUNt and the trigger count TRIGger COUNt must not exceed 512 readings Cannot achieve requested resolution The multimeter cannot achieve the requested measurement resolution You may have specified an invalid resolution in the CONFigure or MEASure command Cannot use overload as math reference The multimeter cannot store an overload reading 9 90000000E 37 as the math reference for null or dB measurements The math state is turned off as a result of this condition Command not allowed in local The multimeter received a READ or MEASure command while in the local mode During RS 232 operation you should always execute the SYSTem REMote command before sending other commands over the interface 178 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 Chapter 5 Error Messages Self Test Errors Self Test Errors The
66. 100 Q 1mA 100 uW 1 ka 1mA 1 mW 10 ka 100 pA 100 uW 100 ka 10 pA 10 pW 1 MQ 5 uA 30 uW 10 Ma 500 nA 3uW Settling Time E ffects The 34401A has the ability to insert automatic measurement settling delays These delays are adequate for resistance measurements with less than 200 pF of combined cable and device capacitance This is particularly important if you are measuring resistances above 100 KQ Settling due to RC time constant effects can be quite long Some precision resistors and multi function calibrators use large parallel capacitors 1000 pF to 0 1 uF with high resistor values to filter out noise currents injected by their internal circuitry Non ideal capacitances in cables and other devices may have much longer settling times than expected just by RC time constants due to dielectric absorption soak effects Errors will be measured when settling after the initial connection and after a range change 204 Chapter 7 Measurement Tutorial Errors in High Resistance Measurements Errors in High Resistance Measurements When you are measuring large resistances significant errors can occur due to insulation resistance and surface cleanliness You should take the necessary precautions to maintain a clean high resistance system Test leads and fixtures are susceptible to leakage due to moisture absorption in insulating materials and dirty surface films Nylon and PVC are relatively poor insulators 10 ohms when
67. 237 10 Quick Start Quick Start One of the first things you will want to do with your multimeter is to become acquainted with its front panel We have written the exercises in this chapter to prepare the multimeter for use and help you get familiar with some of its front panel operations The front panel has two rows of keys to select various functions and operations Most keys have a shifted function printed in blue above the key To perform a shifted function press Shift the Shift annunciator will turn on Then press the key that has the desired label above it For example to select the dc current function press Shift DC V If you accidentally press Shift just press it again to turn off the Shift annunciator The rear cover of this book is a fold out Quick Reference Guide On this cover you will find a quick summary of various multimeter features 12 Chapter 1 Quick Start To Prepare the Multimeter for Use To Prepare the Multimeter for Use The following steps help you verify that the multimeter is ready for use Check the list of supplied items Verify that you have received the following items with your multimeter If anything is missing contact your nearest Agilent Sales Office One test lead kit One power cord This User s Guide One Service Guide One folded Quick Reference card Certificate of Calibration
68. 414 y V V ER taraa 1 732 Ey Se aa o wi T V 1 2 V E t X 1 F 46 for C F 4 The multimeter s ac voltage and ac current functions measure the ac coupled true RMS value This is in contrast to the actdc true RMS value shown above Only the heating value of the ac components of the input waveform are measured dc is rejected For sinewaves triangle waves and square waves the ac and ac dc values are equal since these waveforms do not contain a dc offset Non symmetrical waveforms such as pulse trains contain dc voltages which are rejected by ac coupled true RMS measurements 206 Chapter 7 Measurement Tutorial Crest Factor Errors non sinusoidal inputs An ac coupled true RMS measurement is desirable in situations where you are measuring small ac signals in the presence of large dc offsets For example this situation is common when measuring ac ripple present on dc power supplies There are situations however where you might want to know the ac dc true RMS value You can determine this value by combining results from dc and ac measurements as shown below You should perform the dc measurement using at least 10 power line cycles of integration 6 digit mode for best ac rejection ac dc N ac de Crest Factor Errors non sinusoidal inputs A common misconception is that since an ac multimeter is true RMS its sinewave accuracy specifications apply to all waveforms Actually the shape
69. 68 e JEEE 488 Compliance Information on page 169 If you are a first time user of the SCPI language you may want to refer to these sections to become familiar with the language before attempting to program the multimeter 104 First time SCPI users see page 154 Chapter 4 Remote Interface Reference Command Summary Command Summary This section summarizes the SCPI Standard Commands for Programmable Instruments commands available to program the multimeter Refer to the later sections in this chapter for more complete details on each command Throughout this manual the following conventions are used for SCPI command syntax Square brackets indicate optional keywords or parameters Braces enclose parameters within a command string Triangle brackets lt gt indicate that you must substitute a value for the enclosed parameter The MEASure and CONFigure Commands see page 117 for more information MEASure VOLTage DC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF VOLTage DC RATio lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF VOLTage AC CURRent DC CURRent AC RESistance lt range gt lt range gt lt range gt lt range gt MIN MIN MIN MIN MAX DEF lt resolution gt MAX DEF lt resolution gt MAX DEF lt resolution gt MAX DEF lt resolution gt MIN MIN MIN MIN MAX DEF M
70. 9 test lead resistance 38 64 198 thermal EMF errors 198 threshold resistance continuity 52 transfer accuracy 228 TRG 75 TRIGGER 75 TRIGger COUNt 78 131 TRIGger DELay 80 131 TRIGger DELay AUTO 80 131 TRIGger SOURce 73 130 triggering abort measurements 76 auto trigger 42 73 commands 130 delay 79 external trigger 42 74 83 flowchart 72 front panel 42 idle trigger state 76 129 internal 75 multiple readings samples 77 multiple triggers 78 single trigger 42 73 software bus trigger 75 127 sources 73 wait for trigger state 76 129 TST 86 tutorial front panel menu 29 measurement 197 twisted pair connections 201 two wire ohms connections 17 math functions allowed 63 124 ranges 17 Vv vacuum fluorescent display 1 version firmware 89 SCPI 90 VM Comp terminal 5 83 voltage ac voltage connections 17 loading errors 209 math functions allowed 63 124 ranges 17 signal filter 51 214 dc voltage connections 17 input resistance 53 loading errors 199 math functions allowed 63 124 ranges 17 voltage selector module 15 Voltmeter Complete terminal 5 83 Ww wait for trigger state 76 129 warranty information inside front cover weight product 222 wiring adapter RS 232 149 wiring connections 2 wire ohms 17 4 wire ohms 17 ac current 18 ac volts 17 continuity 19 de current 18 de volts 17 dev dev ratio 44 d
71. A User s Guide Safety Symbols oi 0 eih Earth Ground Chassis Ground Risk of electric shock Refer to manual for addi tional safety information Alternating Current On supply Off supply In position of bi stable push switch Out position of bi stable push switch IEC Measurement Category Il CAT II 300V Inputs may be connected to mains up to 300 VAC under Category Il overvoltage condi tions Main Power and Test Input Dis connect Unplug instrument from wall outlet remove power cord and remove all probes from all terminals before servicing Only qualified service trained person nel should remove the cover from the instrument Line and Current Protection Fuses For continued protection against fire replace the line fuse and the current protection fuse only with fuses of the specified type and rating Front Rear Switch Do not change the position of the Front Rear switch on the front panel while signals are present on either the front or rear set of ter minals The switch is not intended as an active multiplexer Switch ing while high voltages or cur rents are present may cause instrument damage and lead to the risk of electric shock IEC Measurement Category Il The HI and LO input terminals may be connected to mains in IEC Cate gory II installations for line volt ages up to 300 VAC To avoid the danger of electric shock do not connect the inputs to mains for lin
72. ANGE SAVED Keep in mind that math null is turned on and 2 0 volts is used as the null value for measurements To clear the null value press Null This is the end of the front panel menu tutorial The remainder of the chapter discusses several of the most common front panel operations Sy 6 On Off Shift lt v lt A Auto Man ENTER Chapter 2 Front Panel Menu Operation To Turn Off the Comma Separator To Turn Off the Comma Separator The multimeter can display readings on the front panel with or without a comma separator The following steps show how to disable the comma 08 241 53 VDC 08 24153 VDC With comma separator factory setting Without comma separator 1 Turn on the menu A MEAS MENU 2 Move across to the SYS MENU choice on the menus level D SYS MENU 3 Move down a level and then across to the COMMA command 7 COMMA 4 Move down a level and then move across to the OFF choice OFF 5 Save the change and turn off the menu The comma separator setting is stored in non volatile memory and does not change when power has been off or after a remote interface reset Chapter 2 Front Panel Menu Operation To Make Null Relative Measurements To Make Null Relative Measurements Each null measurement also called relative is the difference between a stored null value
73. AX DEF MAX DEF MAX DEF FRESistance lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF FREQuency lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF PERiod lt range gt MIN CONTinuity DIODe CONFigure VOLTage DC lt range gt VOLTage DC RATio lt range VOLTage AC lt range gt CURRent DC lt range gt CURRent AC lt range gt RESistance lt range gt MIN MIN MIN MIN MIN MAX DEF lt resolution gt MIN MAX DEF lt resolution gt MAX DEF lt resolution gt MAX DEF lt resolution gt MAX DEF lt resolution gt MAX DEF lt resolution gt MAX MIN MIN MIN MIN MIN DEF MAX DEF gt MIN MAX DEF lt resolution gt MIN MAX DEF MAX DEF MAX DEF MAX DEF MAX DEF FRESistance lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF FREQuency lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF PERiod lt range gt MIN CONTinuity DIODe CONFigure MAX DEF lt resolution gt MIN MAX DEF 105 Chapter 4 Remote Interface Reference Command Summary Measurement Configuration Commands see page 121 for more information SENSe FUNCtion VOL FUNCtion VOL FUNCtion VOL Tage DC Tage DC RATio Tage AC FUNCtion CURRent DC FUNCtion CURRent AC FU
74. Agilent 34401A 6 Digit Multimeter User s Guide Bee Agilent Technologies Notices Agilent Technologies Inc 1991 2012 No part of this manual may be reproduced in any form or by any means including elec tronic storage and retrieval or translation into a foreign language without prior agree ment and written consent from Agilent Technologies Inc as governed by United States and international copyright laws Manual Part Number 34401 90004 Edition Eighth Edition May 2012 Printed in Malaysia Agilent Technologies Inc 3501 Stevens Creek Blvd Santa Clara CA 95052 USA Microsoft and Windows are U S regis tered trademarks of Microsoft Corporation Software Revision This guide is valid for the firmware that was installed in the instrument at the time of manufacture However upgrading the firm ware may add or change product features For the latest firmware and documentation go to the product page at www agilent com find 34401A Warranty The material contained in this docu ment is provided as is and is sub ject to being changed without notice in future editions Further to the max imum extent permitted by applicable law Agilent disclaims all warranties either express or implied with regard to this manual and any information contained herein including but not limited to the implied warranties of merchantability and fitness for a par ticular purpose Agilent shall not be
75. C REM SInclude QBSetup DEV amp 722 INFO1S RST LENGTH1 LEN INFO1 S INFO2S CLS LENGTH2 LEN INFO2S INFO3S CALC DBM REF 50 LENGTH3 LEN INFO3 INFO4S CONF VOLT AC 1 0 001 LENGTH4 LEN INFO4 INFO5S DET BAND 200 LENGTH5 LEN INFO5 INFO6S TRIG COUN 5 LENGTH6 LEN INFO6S INFO7S TRIG SOUR IMM LENGTH7 LEN INFO7 INFO8S CALC FUNC DBM LENGTH8 LEN INFO8S S INFO9S CALC STAT ON LENGTH9 LEN INFO9S INFO10 READ LENGTH10 LEN INFO10 DIM A 1 5 Actual 0 Call IOCLEAR DEV Call IOOUTPUTS DEV amp INFO1 LENGTH1 Call IOOUTPUTS DEV amp INFO2 LENGTH2 Call IOOUTPUTS DEV amp INFO3 LENGTH3 Call IOOUTPUTS DEV amp INFO4 LENGTH4 Call IOOUTPUTS DEV amp INFO5 LENGTH5 Call IOOUTPUTS DEV amp INFO6 LENGTH6 Call IOOUTPUTS DEV amp INFO7 LENGTH7 Call IOOUTPUTS DEV amp INFO8 LENGTH8 Call IOOUTPUTS DEV amp INFO9 LENGTH9 Call IOOUTPUTS DEV amp INFO10 LENGTH103 Call IOE ER DEV amp Seg A 1 5 Actual For I 1 to 5 Print A I ext I END 187 Chapter 6 Application Programs Using the Status Registers Using the Status Registers The following example shows how you can use the multimeter s status registers to determine w
76. C EN 45014 EN DECLARATION OF CONFORMITY Manufacturer s Name Agilent Technologies Incorporated Manufacturer s Address 815 14 St SW Loveland Colorado 80537 USA Declares that the product Product Name Multimeter Model Number 34401A Product Options This declaration covers all options of the above product s Conforms with the following European Directives The product herewith complies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC including 93 68 EEC and carries the CE Marking accordingly Conforms with the following product standards EMC Standard Limit IEC 61326 1 1997 A1 1998 EN 61326 1 1997 A1 1998 CISPR 11 1990 EN 55011 1991 Group 1 Class A IEC 61000 4 2 1995 A1 1998 EN 61000 4 2 1995 4kV CD 8kV AD IEC 61000 4 3 1995 EN 61000 4 3 1995 3 V m 80 1000 MHz IEC 61000 4 4 1995 EN 61000 4 4 1995 0 5kV signal lines 1kV power lines IEC 61000 4 5 1995 EN 61000 4 5 1995 0 5 kV line line 1 kV line ground IEC 61000 4 6 1996 EN 61000 4 6 1996 3V 0 15 80 MHz IEC 61000 4 11 1994 EN 61000 4 11 1994 Dips 30 10ms 60 100ms Interrupt gt 95 5000ms Canada ICES 001 1998 Australia New Zealand AS NZS 2064 1 The product was tested in a typical configuration with Agilent Technologies test systems Safety IEC 61010 1 1990 A1 1992 A2 1995 EN 61010 1 1993 A2 1995 Canada CSA C22 2 No 1010 1 1992 UL 3111 1 1994 18 July 2001 Dat
77. CD oN Wea eee TX 3 TX DTR 4 4 DTR GND 5 b GND DSR 6 6 DSR RTS 7 J RTS CTS 8 8 CTS RI 9 9 RI DB9 DB9 DB9 DB9 Male Female Female Male DB 25 Serial Connection If your computer or terminal has a 25 pin serial port with a male connector use the null modem cable and 25 pin adapter included with the Agilent 34398A Cable Kit The cable and adapter pin diagram is shown below F1047 80002 5181 6641 C ia gt a E gt Instrument PC Printer DCD 1 1 3 2 TX RX 2 2 2 3 RX TX 3 3 3 4 RTS DTR 4 4 4 5 CTS GND 5 5 o E 6 DSR DSR 6 6 6 7 GND RTS 7 7 2 8 DCD CTS 8 8 8 20 DTR RI 9 9 9 DB9 DB9 DB9 DB9 DB25 DB25 Male Female Female ale Female Male 150 Chapter 4 Remote Interface Reference RS 232 Interface Configuration DTR DSR Handshake Protocol The multimeter is configured as a DTE Data Terminal Equipment device and uses the DTR Data Terminal Ready and DSR Data Set Ready lines of the RS 232 interface to handshake The multimeter uses the DTR line to send a hold off signal The DTR line must be TRUE before the multimeter will accept data from the interface When the multimeter sets the DTR line FALSE the data must cease within 10 characters To disable the DTR DSR handshake do not connect the DTR line and tie the DSR line to logic TRUE If you disable the DTR DSR handshake also select a slower baud rate 300 600 or 1200 baud to ensure that the data is
78. ENU See also To Use Reading Hold on page 43 82 Chapter 3 Features and Functions Triggering Voltmeter Complete Terminal The rear panel VM Comp voltmeter complete terminal provides a low true pulse after the completion of each measurement Voltmeter complete and external trigger see below implement a standard hardware handshake sequence between measurement and switching devices VM Comp Output 5V z OV lt Approximately 2us External Trigger Terminal You can trigger the multimeter by applying a low true pulse to the rear panel Ext Trig external trigger terminal To use this terminal from the remote interface you must select the external trigger source TRIGger SOURce EXTernal Ext Trig Input 5V OV k gt 1 us You can use a simple switch to generate an external trigger using the Ext Trig input as shown below Ext Trig e 83 Chapter 3 Features and Functions System Related Operations System Related Operations This section gives information on topics such as reading memory errors self test and front panel display control This information is not directly related to making measurements but is an important part of operating the multimeter Reading Memory The multimeter can store up to 512 readings in internal memory Readings are stored in first in first out FIFO order The first reading returned is the first reading stored
79. Equipment WEEE Directive 2002 96 EC This product complies with the WEEE Direc tive 2002 96 EC marking requirement The affixed product label see below indi cates that you must not discard this electri cal electronic product in domestic household waste Product Category With reference to the equipment types in the WEEE directive Annex 1 this product is classified as a Monitoring and Control instrumentation product Do not dispose in domestic household waste To return unwanted products contact your local Agilent office or see www agilent com environment product for more information Agilent 34138A Test Lead Set The Agilent 34401A is compatible with the Agilent 34138A Test Lead Set described below Test Lead Ratings Test Leads 1000V 15A Fine Tip Probe Attachments 300V 3A Mini Grabber Attachment 300V 3A SMT Grabber Attachments 300V 3A Operation The Fine Tip Mini Grabber and SMT Grab ber attachments plug onto the probe end of the Test Leads Maintenance If any portion of the Test Lead Set is worn or damaged do not use Replace with a new Agilent 34138A Test Lead Set If the Test Lead Set is used ina manner not specified by Agilent Technologies the protection pro vided by the Test Lead Set may be impaired Also do not use a dam aged or worn Test Lead Set Instrument damage or personal injury may result oem Agilent Technologies According to ISO IEC Guide 22 and CEN CENELE
80. Error code e Remote Interface Operation SYSTem ERRor Reads one error from the error queue Errors have the following format the error string may contain up to 80 characters 113 Undefined header 172 101 102 103 104 105 108 109 Chapter 5 Error Messages Execution Errors Execution Errors Invalid character An invalid character was found in the command string You may have inserted a character such as or in the command header or within a parameter Example CONF VOLT DC Syntax error Invalid syntax was found in the command string You may have inserted a blank space before or after a colon in the command header or before a comma Example SAMP COUN pl Invalid separator An invalid separator was found in the command string You may have used a comma instead of a colon semicolon or blank space or you may have used a blank space instead of a comma Example TRIG COUN 1 or CONF FREQ 1000 0 1 Data type error The wrong parameter type was found in the command string You may have specified a number where a string was expected or vice versa Example DISP TEXT 5 0 GET not allowed A Group Execute Trigger GET is not allowed within a command string Parameter not allowed More parameters were received than expected for the command You may have entered an extra parameter or you added a parameter to a command that does not accept a parameter Exam
81. Features and Functions Math Operations Limit Testing e Remote Interface Operation You can use the following commands for limit testing continued CALCu CALCul CALCU late ate ate FUNCtion LIMit STATe OFF ON LIMit LOWer lt value gt MINimum MAXimum CALCul ate LIMit UPPer lt value gt MINimum MAXimum There are two unused pins on the RS 232 interface connector which are available to indicate the pass fail status of readings taken with limit testing To configure these pins for limit testing you must install two jumpers inside the multimeter See the Service Guide for more information A low going pulse is output to pin 1 for each reading that is within the specified limits A low going pulse is output to pin 9 for each reading that exceeds the upper or lower limit 5V OV As 232 9 rs Pin 1 Pass Output 2ms Pin 9 Fail Output minimum Caution Do not use the RS 232 interface if you have configured the multimeter to output pass fail signals on pins 1 and 9 Internal components on the RS 232 interface circuitry may be damaged 70 Chapter 3 Features and Functions Triggering Triggering The multimeter s triggering system allows you to generate triggers either manually or automatically take multiple readings per trigger and insert a delay before each reading Normally the multimeter will take one reading each time it receives a trigger but you can specify
82. I to LO Input terminals is 1000 VDC or 750 VAC which is also the maximum voltage measurement This limit can also be expressed as 1000 Vpk maximum LO to Ground Protection Limit The LO input terminal can safely float a maxi mum of 500 Vpk relative to ground As is implied by the above limits the Protec tion Limit for the HI input terminal is a maxi mum of 1500 Vpk relative to ground Current Input Terminal The current input I terminal has a Protection Limit of 3A rms maximum current flowing from the LO input terminal Note that the current input terminal will be at approximately the same voltage as the LO terminal Note The current protection circuitry includes a fuse on the rear panel To main tain protection replace this fuse only with a fuse of the specified type and rating Sense Terminal Protection Limits The HI and LO sense terminals are used only for four wire resistance and tempera ture measurements Q 4W The Protec tion Limit is 200 Vpk for all of the terminal pairings LO sense to LO input HI sense to LO input HI sense to LO sense Note The 200 Vpk limit on the sense termi nals is the Protection Limit Operational voltages in resistance measurements are much lower less than 10 V in normal operation IEC Measurement Category Il Overvoltage Protection To protect against the danger of electric shock the Agilent 34401A Digital Multime ter provides overvoltage protection for line
83. Interface Reference The SCPI Status Model The SCPI Status Model All SCPI instruments implement status registers in the same way The status system records various instrument conditions in three register groups the Status Byte register the Standard Event register and the Questionable Data register The status byte register records high level summary information reported in the other register groups The diagram on the next page illustrates the SCPI status system Chapter 6 Application Programs contains an example program showing the use of the status registers You may find it useful to refer to the program after reading the following section in this chapter What is an Event Register The standard event and questionable data registers have event registers An event register is a read only register that reports defined conditions within the multimeter Bits in the event registers are latched Once an event bit is set subsequent state changes are ignored Bits in an event register are automatically cleared by a query of that register such as ESR or STAT QUES EVEN or by sending the CLS clear status command A reset RST or device clear will not clear bits in event registers Querying an event register returns a decimal value which corresponds to the binary weighted sum of all bits set in the register What is an Enable Register An enable register defines which bits in the corresponding ev
84. NCtion RESistance 2 wire ohms FUNCtion FRESistance 4 wire ohms FUNCtion FREQuency FUNCtion PERiod FUNCtion CONTinuity FUNCtion DIODe FUNCtion SENSe VOLTage DC RANGe lt range gt MINimum MAXimum VOLTage DC RANGe Nimum MAXimum VOLTage AC RANGe lt range gt Nimum MAXimum VOLTage AC RANGe Nimum MAXimum CURRent DC RANGe lt range gt Nimum MAXimum CURRent DC RANGe Nimum MAXimum CURRent AC RANGe lt range gt Nimum MAXimum CURRent AC RANGe Nimum MAXimum RESistance RANGe lt range gt Nimum MAXimum RESistance RANGe Nimum MAXimum FRESistance RANGe lt range gt MINimum MAXimum FRESistance RANGe MINimum MAXimum FREQuency VOLTage RANGe lt range gt MINimum MAXimum FREQuency VOLTage RANGe MINimum MAXimum PERiod VOLTage RANGe lt range gt MINimum MAXimum PERiod VOLTage RANGe MINimum MAXimum SENSe VOLTage DC RANGe AUTO OFF ON VOLTage DC RANGe AUTO VOLTage AC RANGe AUTO OFF ON VOLTage AC RANGe AUTO CURRent DC RANGe AUTO OFF ON CURRent DC RANGe AUTO CURRent AC RANGe AUTO OFF ON CURRent AC RANGe AUTO RESistance RANGe AUTO OFF ON RESistance RANGe AUTO FRESistance RANGe AUTO OFF ON FRESistance RANGe AUTO FREQuency VOLTage RANGe AUTO OFF ON FREQuency VOLTage RANGe AUTO PERiod VOLTage RANGe AUTO OFF ON PERiod VOLTage RANGe AUTO Default parameters are shown in bold 106 Chapter 4 Remote Interfac
85. NG MENU USE TOP OF MENU You pressed while on the menus level this is the top level of the menu and you cannot go any higher To turn off the menu press Shift lt Menu On Off To move across the choices on a level press lt or gt To move down a level press v MENUS You are onthe menus level Press lt or gt to view the choices COMMANDS You are on the commands level Press lt or gt to view the command choices within the selected menu group PARAMETER You are on the parameter level Press lt or gt to view and edit the parameter for the selected command MENU BOTTOM You pressed lv while on the parameter level this is the bottom level of the menu and you cannot go any lower To turn off the menu press Shift lt Menu On Off To move up a level press la CHANGE SAVED The change made on the parameter level is saved This is displayed after you press Auto Man Menu Enter to execute the command MIN VALUE The value you specified on the parameter level is too small for the selected command The minimum value allowed is displayed for you to edit MAX VALUE The value you specified on the parameter level is too large for the selected command The maximum value allowed is displayed for you to edit EXITING MENU You will see this message if y
86. ONFigure with a Math Operation 186 Using the Status Registers 188 RS 232 Operation Using QuickBASIC 192 RS 232 Operation Using Turbo C 193 c c O O Contents Chapter 7 Measurement Tutorial Thermal EMF Errors 199 Loading Errors de volts 199 Leakage Current Errors 199 Rejecting Power Line Noise Voltages 200 Common Mode Rejection CMR 201 Noise Caused by Magnetic Loops 201 Noise Caused by Ground Loops 202 Resistance Measurements 203 4 Wire Ohms Measurements 203 Removing Test Lead Resistance Errors 204 Power Dissipation Effects 204 Settling Time Effects 204 Errors in High Resistance Measurements 205 DC Current Measurement Errors 205 True RMS AC Measurements 206 Crest Factor Errors 207 Loading Errors ac volts 209 Measurements Below Full Scale 210 High Voltage Self Heating Errors 210 Temperature Coefficient and Overload Errors 210 Low Level Measurement Errors 211 Common Mode Errors 212 AC Current Measurement Errors 212 Frequency and Period Measurement Errors 213 Making High Speed DC and Resistance Measurements 213 Making High Speed AC Measurements 214 Chapter 8 Specifications DC Characteristics 216 AC Characteristics 218 Frequency and Period Characteristics 220 General Information 222 Product Dimensions 223 To Calculate Total Measurement Error 224 Interpreting Multimeter Specifications 226 Configuring for Highest Accuracy Measurements 229 Index 231 Declaration of Conformity
87. Panel Menu Operation Front Panel Menu Reference D SYStem MENU 1 RDGS STORE gt 2 SAVED RDGS gt 3 ERROR gt 4 TEST gt 5 DISPLAY gt 6 BEEP gt 7 COMMA gt 8 REVISION RDGS STORE SAVED RDGS ERROR TEST DISPLAY BEEP COMMA REVISION E Input Output MENU Enables or disables reading memory Recalls readings stored in memory up to 512 readings Retrieves errors from the error queue up to 20 errors Performs a complete self test Enables or disables the front panel display Enables or disables the beeper function Enables or disables a comma separator between digits on the display Displays the multimeter s firmware revision codes 1 GPIB ADDR gt 2 INTERFACE gt 3 BAUD RATE gt 4 PARITY gt 5 LANGUAGE 1 HP IB ADDR 2 INTERFACE 3 BAUD RATE 4 PARITY 5 LANGUAGE F CALibration MENU Sets the GPIB bus address 0 to 31 Selects the GPIB or RS 232 interface Selects the baud rate for RS 232 operation Selects even odd or no parity for RS 232 operation Selects the interface language SCPI Agilent 3478 or Fluke 8840 42 1 SECURED gt 1 UNSECURED gt 2 CALIBRATE gt 3 CAL COUNT gt 4 MESSAGE 1 SECURED 1 UNSECURED 2 CALIBRATE 3 CAL COUNT 4 MESSAGE The multimeter is secured against calibration enter code to unsecure The multimeter is unsecured for calibration enter code to secure Performs complete calibr
88. Query the input resistance mode Returns 0 OFF or 1 ON ROUTe TERMinals Query the multimeter to determine if the front or rear input terminals are selected Returns FRON or REAR 123 Chapter 4 Remote Interface Reference Math Operation Commands Math Operation Commands See also Math Operations starting on page 63 in chapter 3 There are five math operations available only one of which can be enabled at a time Each math operation performs a mathematical operation on each reading or stores data on a series of readings The selected math operation remains in effect until you disable it change functions turn off the power or perform a remote interface reset The math operations use one or more internal registers You can preset the values in some of the registers while others hold the results of the math operation The following table shows the math measurement function combinations allowed Each X indicates an allowable combination If you choose a math operation that is not allowed with the present measurement function math is turned off If you select a valid math operation and then change to one that is invalid a Settings conflict error is generated over the remote interface For null and dB measurements you must turn on the math operation before writing to their math registers Null Min Max dB dBm Limit DCV ACV DCI ACI 22W Q 4W Freq Per Cont Diode Ratio X X X X
89. R gt 4 TEST gt 5 DISPLAY gt 6 BEEP gt 7 COMMA gt 8 REVISION E Input Output MENU 1 GPIB ADDR gt 2 INTERFACE gt 3 BAUD RATE gt 4 PARITY gt 5 LANGUAGE F CALibration MENU 1 SECURED gt 1 UNSECURED gt 2 CALIBRATE gt 3 CAL COUNT gt 4 MESSAGE The commands enclosed in square brackets are hidden unless the multimeter is UNSECURED for calibration Display Annunciators 61 2 Digit Multimeter RRERRRERR RAD x Adrs Rm Man Trig Hold Mem Raho Math ERROR Rear Shift i xt Agi lent 344014 x Turns on during a measurement Adrs Multimeter is addressed to listen or talk over the GPIB interface Rmt Multimeter is in remote mode remote interface Man Multimeter is using manual ranging autorange is disabled Trig Multimeter is waiting for a single trigger or external trigger Hold Reading Hold is enabled Mem Turns on when reading memory is enabled Ratio Multimeter is in dcv dcv ratio function Math A math operation is enabled null min max dB dBm or limit test Hardware or remote interface command errors are detected ERROR gt Rear input terminals are selected Rear A Shift key has been pressed Press Shift again to turn off Shift rae 3 3 ed Multimeter is in 4 wire ohms function Multimeter is in continuity test function gt Multimeter is in diode test function To review the display annunciat
90. S and a READ command is received 175 221 222 223 224 230 330 Chapter 5 Error Messages Execution Errors Settings conflict This error can be generated in one of the following situations e You sent a CONFigure or MEASure command with autorange enabled and with a fixed resolution Example CONF VOLT DC DEF 0 1 e You turned math on CALC STAT ON and then changed to a math operation that was not valid with the present measurement function For example dB measurements are not allowed with 2 wire ohms The math state is turned off as a result of this condition Data out of range A numeric parameter value is outside the valid range for the command Example TRIG COUN 3 Too much data A character string was received but could not be executed because the string length was more than 12 characters This error can be generated by the CALibration STRing and DISPlay TEXT commands Illegal parameter value A discrete parameter was received which was not a valid choice for the command You may have used an invalid parameter choice Example CALC FUNC SCALE SCALE is not a valid choice Data stale A FETCh command was received but internal reading memory was empty The reading retrieved may be invalid Self test failed The multimeter s complete self test failed from the remote interface TST command In addition to this error more specific self test errors are also reported See also
91. SOURce BUS Front panel Single key Trigger Delay TRIGger DELay Sample Annunciator Measurement Sample Sample Count 1 Trigger Count 1 128 Chapter 4 Remote Interface Reference Triggering The Wait for Trigger State After you have configured the multimeter and selected a trigger source you must place the multimeter in the wait for trigger state A trigger will not be accepted until the multimeter is in this state If a trigger signal is present and if multimeter is in the wait for trigger state the measurement sequence begins and readings are taken The wait for trigger state is a term used primarily for remote interface operation From the front panel the multimeter is always in the wait for trigger state and will accept triggers at any time unless a measurement is already in progress You can place the multimeter in the wait for trigger state by executing any of the following commands from the remote interface MEASure READ INITiate The multimeter requires approximately 20 ms of set up time after you send a command to change to the wait for trigger state Any external triggers that occur during this set up time are ignored 129 Chapter 4 Remote Interface Reference Triggering Commands Triggering Commands See also Triggering starting on page 71 in chapter 3 INITiate Change the state of the triggering system from
92. Standard Commands for Programmable Instruments is an ASCII based instrument command language designed for test and measurement instruments Refer to Simplified Programming Overview starting on page 112 for an introduction to the basic techniques used to program the multimeter over the remote interface SCPI commands are based on a hierarchical structure also known as a tree system In this system associated commands are grouped together under a common node or root thus forming subsystems A portion of the SENSE subsystem is shown below to illustrate the tree system SENSe VOLTage DC RANGe lt range gt MINimum MAXimum VOLTage DC RANGe MINimum MAXimum FREQuency VOLTage RANGe lt range gt MINimum MAXimum FREQuency VOLTage RANGe MINimum MAXimum DETector BANDwidth 3 20 200 MINimum MAXimum DETector BANDwidth MINimum MAXimum ZERO AUTO OFF ONCE ON ZERO AUTO n ENSe is the root keyword of the command VOLTage and FREQuency are second level keywords and DC and VOLTage are third level keywords A colon separates a command keyword from a lower level keyword 154 Chapter 4 Remote Interface Reference An Introduction to the SCPI Language Command Format Used in This Manual The format used to show commands in this manual is shown below VOLTage DC RANGe lt range gt MINimum MAXimum The command syntax shows most commands
93. The reading memory feature is available only from the front panel e You can use reading memory with all functions math operations and also reading hold After you have enabled reading memory you can change the function Be aware however that the function labels VDC OHM etc are not stored with the reading e Readings taken while reading memory is enabled are stored in volatile memory the multimeter clears the stored readings when reading memory is turned on again when power has been off after a self test or after a remote interface reset e You can use reading memory with auto trigger single trigger external trigger and reading hold If you configure the multimeter for multiple readings per trigger the specified number of readings are stored in memory each time a trigger is received e Front Panel Operation 1 RDGS STORE SYS MENU store readings in memory 2 SAVED RDGS SYS MENU read the stored readings Reading memory is automatically turned off when you go to the parameter level in the menu to recall the readings See also To Use Reading Memory on page 46 e Remote Interface Operation The INITiate command uses reading memory to store readings prior to a FETCh command You can query the number of stored readings in memory by sending the DATA POINts command from the remote interface 84 Chapter 3 Features and Functions System Related Operations Error Conditions When the front pan
94. _enab OxEF IRQ4 interrupt controller enable mask define INT_controller 0x20 8259 Interrupt controller address define End_of_interrupt 0x20 Non specific end of interrupt command void interrupt int_char_in void void send_ctlc void define INT_BUF_size 9000 char int_buf INT_BUF_size int_buf_in int_buf int_buf_out int_buf unsigned int int_buf_count 0 unsigned char int_buf_ovfl 0 int main int argc char argv void interrupt oldvect char command 80 c LAG I7 oldvect getvect IRQ4_int Save old interrupt vector setvect IRQ4_int int_char_in Set up new interrupt handler bioscom 0 BAUD9600 EVEN_7 0 Initialize settings for COM1 outportb MCR 0x9 Enable IRQ buffer DTR 1 outporth IER 0x1 Enable UART data receive interrupt Enable IRQ4 in 8259 interrupt controller register outportb INT_controller 1l inportb INT_controllert l amp IRQ4_enab do if int_buf_ovfl printf nBuffer Overflow n n int_buf_in int_buf_out int_buf int_buf_count int_buf_ovfl 0 Continued on next page gt 194 Chapter 6 Application Programs RS 232 Operation Using Turbo C RS 232 Operation Using Turbo C continued printf nEnter command string n gets command strcat command n SCPI requires line feed if command 0 0x19 send_ctlc If Y then s
95. a crest factor of 3 and a fundamental frequency of 20 kHz For this example assume the multimeter s 90 day accuracy specifications 0 05 0 03 Total Error 0 08 0 15 1 4 1 6 208 Chapter 7 Measurement Tutorial Loading Errors ac volts Loading Errors ac volts In the ac voltage function the input of the Agilent 34401A appears as a 1 MQ resistance in parallel with 100 pF of capacitance The cabling that you use to connect signals to the multimeter will also add additional capacitance and loading The table below shows the multimeter s approximate input resistance at various frequencies Input Frequency Input Resistance 100 Hz 1 MQ 1 kHz 850 ka 10 kHz 160 ka 100 kHz 16 ka For low frequencies 100 x R Error ___ R 1MQ Additional error for high frequencies Error 100 x 1 N 1 22x Fx Rs x Cin Rs source resistance F input frequency Cin input capacitance 100 pF plus cable capacitance 209 Chapter 7 Measurement Tutorial Measurements Below Full Scale Measurements Below Full Scale You can make the most accurate ac measurements when the multimeter is at full scale of the selected range Autoranging occurs at 10 and 120 of full scale This enables you to measure some inputs at full scale on one range and 10 of full scale on the next higher range The accuracy will be significantly different for these two cases For highest accuracy
96. ace command you append this address to the GPIB interface s select code normally 7 Therefore with an address of 22 and a select code of 7 the combination is 722 IBM is a U S registered trademark of International Business Machines Corporation 184 Chapter 6 Application Programs Using MEASure for a Single Measurement Using MEASure for a Single Measurement The following example uses the MEASure command to make a single ac current measurement This is the easiest way to program the multimeter for measurements However MEASure does not offer much flexibility The example is shown in BASIC and QuickBASIC GPIB Operation Using BASIC 10 REAL Rdg 20 ASSIGN Dmm TO 722 30 CLEAR 7 Clear GPIB and dmm 40 OUTPUT Dmm RST Reset dmm 50 OUTPUT Dmm CLS Clear dmm status registers 60 OUTPUT Dmm MEASURE CURRENT AC 1A 0 001MA Set to 1 amp ac range 70 ENTER Dmm Rdg 80 PRINT Rdg 90 END GPIB Operation Using QuickBASIC EM S Include QBSetup EV amp 722 FO1S RST ENGTH1 LEN INFO1S FO2S CLS ENGTH2 LEN INFO2S FO3S MEASURE CURRENT AC 1A 0 001MA ENGTH3 LEN INFO3 Poe aonw Call IOCLEAR DEV amp Call IOOUTPUTS DEV INFO1S LENGTH1 Call IOOUTPUTS DEV amp INFO2S LENGTH2 Call IOOUTPUTS DEV amp INFO3S LENGTH3 Call IOENTER DEVE Rdg Pri
97. address is stored in non volatile memory and does not change when power has been off or after a remote interface reset e You can set the address to 31 which is the talk only mode In this mode the multimeter can output readings directly to a printer without being addressed by a bus controller over either GPIB or RS 232 For proper operation make sure your printer is configured in the listen always mode Address 31 is not a valid address if you are operating the multimeter from the GPIB interface with a bus controller If you select the RS 232 interface and then set the GPIB address to the talk only address 31 the multimeter will send readings over the RS 232 interface when in the local mode e Ifyou select the RS 232 interface and then set the GPIB address to the talk only address 31 the multimeter will send readings over the RS 232 interface when in the local mode e Your GPIB bus controller has its own address Be sure to avoid using the bus controller s address for any instrument on the interface bus Agilent controllers generally use address 21 e Front Panel Operation 1 GPIB ADDR I O MENU See also To Set the GPIB Address on page 161 91 Chapter 3 Features and Functions Remote Interface Configuration Remote Interface Selection The multimeter is shipped with both an GPIB IEEE 488 interface and an RS 232 interface Only one interface can be enabled at a time The GPIB interface is selected
98. ail testing to upper and lower limits that you specify Applies to all measurement functions except continuity and diode tests e You can set the upper and lower limits to any value between 0 and 120 of the highest range for the present function The upper limit selected should always be a more positive number than the lower limit The default upper and lower limits are both 0 e The upper and lower limits are stored in volatile memory the multimeter sets both limits to 0 when power has been off after a remote interface reset or after a function change e You can configure the multimeter to generate a service request SRQ on the first occurrence of a failed reading See The SCPI Status Model starting on page 134 for more information e Front Panel Operation The multimeter displays OK for each reading that is within the specified limits It displays HI or LO for each reading that exceeds the upper or lower limit The multimeter beeps once if the front panel beeper is enabled on the first occurrence of a failed reading after a good reading See also Beeper Control on page 88 5 LIMIT TEST MATH MENU enable or disable limit test 6 HIGH LIMIT MATH MENU set the upper limit 7 LOW LIMIT MATH MENU set the lower limit You can also turn off limit test by selecting a different math operation from the front panel only one math operation can be enabled at a time 69 Chapter 3
99. alue use the MATH menu 7 34401A yE Agilent 317 Digit Multimeter a BE Math Enables dB operation Math annunciator is on when Press again to disable dB operation is enabled e Select DCV or ACV e The first reading taken after you enable dB measurements is converted to dBm and is stored as the relative value in the dB Relative Register Any previously stored value is replaced with the new value e After enabling dB operations you can edit the relative value by pressing Shift gt Menu Recall This takes you to the dB REL command in the MATH MENU only if dB is enabled Go down to the parameter level and then edit the value displayed e The register is cleared when you change functions turn dB off turn off the power or perform a remote interface reset 40 Chapter 2 Front Panel Menu Operation To Make dBm Measurements To Make dBm Measurements The dBm operation calculates the power delivered to a resistance referenced to 1 milliwatt dBm 10 x Log reading reference resistance 1 mW To read edit the dBm reference resistance use the MATH menu H 34401A ye Agilent 61 2 Digit Multimeter RERERRERER Math Enables dBm operation Math annunciator is on when Press again to disable dBm operation is enabled e Select DCV or ACV e The factory setting for the reference resistance is 600 Q To select a different
100. alue to any number between 0 and 120 of the highest range for the present function MIN 120 of the highest range MAX 120 of the highest range Stored in volatile memory CALCulate LIMit LOWer MINimum MAXimum Query the lower limit CALCulate LIMit UPPer lt value gt MINimum MAXimum Set the lower limit for limit testing You can set the value to any number between 0 and 120 of the highest range for the present function MIN 120 of the highest range MAX 120 of the highest range Stored in volatile memory CALCulate LIMit UPPer MINimum MAXimum Query the upper limit DATA FEED RDG STORE CALCulate Selects whether readings taken using the INITiate command are stored in the multimeter s internal memory default or not stored at all In the default state DATA FEED RDG_STORE CALC up to 512 readings are stored in memory when INITiate is executed The MEASure and CONFigure commands automatically select CALC With memory disabled DATA FEED RDG_STORE readings taken using INITiate are not stored This may be useful with the min max operation since it allows you to determine an average of the readings without storing the individual values An error will be generated if you attempt to transfer readings to the output buffer using the FETCh command DATA FEED Query the reading memory state Returns CALC or 126 First time SCPI users see page
101. ar panel Ext Trig external trigger terminal Stored in volatile memory TRIGger SOURce Query the present trigger source Returns BUS IMM or EXT 130 Chapter 4 Remote Interface Reference Triggering Commands TRIGger DELay lt seconds gt MINimum MAXimum Insert a trigger delay between the trigger signal and each sample that follows If you do not specify a trigger delay the multimeter automatically selects a delay for you Select from 0 to 3600 seconds MIN 0 seconds MAX 3600 seconds Stored in volatile memory TRIGger DELay MINimum MAXimum Query the trigger delay TRIGger DELay AUTO OFF ON Disable or enable an automatic trigger delay The delay is determined by function range integration time and ac filter setting Selecting a specific trigger delay value automatically turns off the automatic trigger delay Stored in volatile memory TRIGger DELay AUTO Query the automatic trigger delay setting Returns 0 OFF or 1 ON SAMPle COUNt lt value gt MINimum MAXimum Set the number of readings samples the multimeter takes per trigger Select from 1 to 50 000 readings per trigger MIN 1 MAX 50 000 Stored in volatile memory SAMPle COUNt MINimum MAXimum Query the sample count TRIGger COUNt lt value gt MINimum MAXimum INFinite Set the number of triggers the multimeter will accept before returning to the idle state Select from 1 to 50 000 trigg
102. asurement with the specified range and resolution This command does not initiate the measurement For frequency measurements the multimeter uses one range for all inputs between 3 Hz and 300 kHz With no input signal applied frequency measurements return 0 CONFigure PERiod lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure a period measurement with the specified range and resolution This command does not initiate the measurement For period measurements the multimeter uses one range for all inputs between 0 33 seconds and 3 3 usec With no input signal applied period measurements return 0 CONFigure CONTinuity Preset and configure the multimeter for continuity measurements This command does not initiate the measurement The range and resolution are fixed for continuity tests 1 KQ range and 51 digits CONF igure DIODe Preset and configure the multimeter for diode measurements This command does not initiate the measurement The range and resolution are fixed for diode tests 1 Vdc range with 1 mA current source output and 5 digits CONFigure Query the multimeter s present configuration and return a quoted string 120 Chapter 4 Remote Interface Reference Measurement Configuration Commands Measurement Configuration Commands See also Measurement Configuration starting on page 51 in chapter 3 FUNCtion lt function gt Select a measurement fun
103. ation of present function must be UNSECURED Reads the total number of times the multimeter has been calibrated Reads the calibration string up to 12 characters entered from remote The commands enclosed in square brackets are hidden unless the multimeter is UNSECURED for calibration 28 Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial A Front Panel Menu Tutorial This section is a step by step tutorial which shows how to use the front panel menu We recommend that you spend a few minutes with this tutorial to get comfortable with the structure and operation of the menu The menu is organized in a top down tree structure with three levels menus commands and parameters You move down lv or up a the menu tree to get from one level to the next Each of the three levels has several horizontal choices which you can view by moving left lt or right gt Menus Commands Parameters e To turn on the menu press To turn off the menu press Shift Menu On Off Shift Menu On Off or press any of the function or math keys on the top row of front panel keys e To execute a menu command press To recall the last menu command that was executed press Shift Recall 29 Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial MESSAGES DISPLAYED DURI
104. ative value is stored in the multimeter s dB Relative Register There are two ways you can specify the relative value First you can enter a specific number into the register from the front panel menu or from the remote interface Any previously stored value is replaced with the new value If you are operating the multimeter from the front panel entering a relative value also turns on the dB function The second way to enter the relative value is to let the multimeter take the first reading convert it to dBm and store that value in the register Changing the dBm reference resistance see page 68 does not change the stored relative value After you enable dB the first reading taken will be 0 dB if you have not changed the value stored in the register If you entered a number into the register as described in the paragraph above the first reading does not overwrite the stored value e Front Panel Operation After enabling dB you can edit the stored relative value by pressing Shift gt Menu Recall Any previously stored value is replaced with the new value Turning on the menu does not disable the dB operation the multimeter will resume taking measurements when you turn off the menu 3 dB REL MATH MENU See also To Make dB Measurements on page 40 67 Chapter 3 Features and Functions Math Operations Remote Interface Operation You can use the following commands to make dB measurements Math must b
105. by pressing Single It is like the single trigger mode except that you apply a trigger pulse to the rear panel Ext Trig terminal The multimeter is triggered on the negative edge of a TTL pulse The front panel Single key is disabled when in remote 42 Chapter 2 Front Panel Menu Operation To Use Reading Hold To Use Reading Hold The reading hold feature allows you to capture and hold a stable reading on the display When a stable reading is detected the multimeter emits a beep and holds the value on the display To adjust the reading hold sensitivity band use the TRIG menu Jeg i 34401A te Agilent 61 2 Digit Multimeter Auto Hold RRRERRE Hold Toggles between auto trigger Hold annunciator is on when and reading hold reading hold is enabled e Reading hold has an adjustable sensitivity band to allow you to select which readings are considered stable enough to be displayed The band is expressed as a percent of reading on the selected range The multimeter will capture and display a new value only after three consecutive readings are within the band e The default band is 0 10 of reading After enabling reading hold you can choose a different band by pressing Shift gt Menu Recall This takes you to the READ HOLD command in the TRIG MENU only if reading hold is enabled Go down to the parameter level and then select a value 0 01 0 10 1 00
106. code Calibration Count You can determine the number of times that your multimeter has been calibrated Your multimeter was calibrated before it left the factory When you receive your multimeter read the count to determine its initial value e The calibration count is stored in non volatile memory and does not change when power has been off or after a remote interface reset e The calibration count increments up to a maximum of 32 767 after which it wraps around to 0 Since the value increments by one for each calibration point a complete calibration increases the value by several counts e Front Panel Operation 3 CAL COUNT CAL MENU Remote Interface Operation CALibration COUNt 98 Chapter 3 Features and Functions Calibration Overview Calibration Message You can use the calibration message feature to record calibration information about your multimeter For example you can store such information as the last calibration date the next calibration due date the multimeter s serial number or even the name and phone number of the person to contact for a new calibration You can record information in the calibration message only from the remote interface However you can read the message from either the front panel menu or the remote interface e The calibration message may contain up to 40 characters However the multimeter can display only 12 characters of the message on the front panel ad
107. compared to PTFE PTFE insulators 10 ohms Leakage from nylon or PVC insulators can easily contribute a 0 1 error when measuring a 1 MQ resistance in humid conditions DC Current Measurement Errors When you connect the multimeter in series with a test circuit to measure current a measurement error is introduced The error is caused by the multimeter s series burden voltage A voltage is developed across the wiring resistance and current shunt resistance of the multimeter as shown below Rs Vs source voltage Rs DUT source resistance Vb multimeter burden voltage R multimeter current shunt 100 x Vb Error V S 205 Chapter 7 Measurement Tutorial True RMS AC Measurements True RMS AC Measurements True RMS responding multimeters like the Agilent 34401A measure the heating potential of an applied voltage Unlike an average responding measurement a true RMS measurement is used to determine the power dissipated in a resistor The power is proportional to the square of the measured true RMS voltage independent of waveshape An average responding ac multimeter is calibrated to read the same as a true RMS meter for sinewave inputs only For other waveform shapes an average responding meter will exhibit substantial errors as shown below Waveform Crest Factor Average Shape C F AC RMS AC DC RMS Responding Error A 1 414 v y Calibrated for O error 1 414 1
108. ct the measurement function range and resolution all in one command Use the range parameter to specify the expected value of the input signal The multimeter then selects the correct measurement range For frequency and period measurements the multimeter uses one range for all inputs between 3 Hz and 300 kHz The range parameter is required only to specify the resolution Therefore it is not necessary to send a new command for each new frequency to be measured Use the resolution parameter to specify the desired resolution for the measurement Specify the resolution in the same units as the measurement function not in number of digits For example for dc volts specify the resolution in volts For frequency specify the resolution in hertz You must specify a range to use the resolution parameter Using the READ Command The READ command changes the state of the trigger system from the idle state to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied following the receipt of the READ command Readings are sent immediately to the output buffer You must enter the reading data into your bus controller or the multimeter will stop making measurements when the output buffer fills Readings are not stored in the multimeter s internal memory when using the READ command Sending the READ command is like sending the INITiate command followed immediately by th
109. ction The function must be enclosed in quotes in the command string FUNC VOLT DC Specify one of the following strings VOLTage DC FRESistance 4 wire ohms VOLTage DC RATio FREQuency VOLTage AC PERiod CURRent DC CONTinuity CURRent AC DIODe RESistance 2 wire ohms FUNCtion Query the measurement function and return a quoted string lt function gt RANGe lt range gt MINimum MAXimum Select the range for the selected function For frequency and period measurements ranging applies to the signal s input voltage not its frequency use FREQuency VOLTage or PERiod VOLTage MIN selects the lowest range for the selected function MAX selects the highest range Stored in volatile memory lt function gt RANGe MINimum MAXimum Query the range for the selected function lt function gt RANGe AUTO OFF ON Disable or enable autoranging for the selected function For frequency and period use FREQuency VOLTage or PERiod VOLTage Autorange thresholds Down range at lt 10 of range Up range at gt 120 of range Stored in volatile memory lt function gt RANGe AUTO Query the autorange setting Returns 0 OFF or 1 ON 121 Chapter 4 Remote Interface Reference Measurement Configuration Commands lt function gt RESolution lt resolution gt MINimum MAXimum Select the resolution for the specified function not valid for frequency period or ratio Specify the r
110. d when in remote Remote Interface Operation TRIGger SOURce EXTernal 74 Chapter 3 Features and Functions Triggering Internal Triggering In the internal trigger mode remote interface only the trigger signal is always present When you place the multimeter in the wait for trigger state the trigger is issued immediately This is the power on trigger source for remote interface operation To select the internal trigger source send the following command The CONFigure and MEASure commands automatically set the trigger source to IMMediate TRIGger SOURce IMMediate Software Bus Triggering The bus trigger mode is available only from the remote interface This mode is similar to the single trigger mode from the front panel but you trigger the multimeter by sending a bus trigger command e To select the bus trigger source send the following command TRIGger SOURce BUS To trigger the multimeter from the remote interface GPIB or RS 232 send the TRG trigger command The TRG command will not be accepted unless the multimeter is in the wait for trigger state e You can also trigger the multimeter from the GPIB interface by sending the IEEE 488 Group Execute Trigger GET message The multimeter must be in the wait for trigger state The following statement shows how to send a GET using BASIC TRIGGER 722 Group Execute Trigger 75 Chapter 3 Features and Functions Triggering The Wait for Tri
111. da N10149 Chapter 8 Specifications Product Dimensions E Product Dimensions Ge Hane j oo 60000000 Oe 103 8 mm oe000000 ante J 379 4 mm a HU 261 1 mm RE 1 2 O og299990 Se gs smm S9 ac0ca000 2126mm a 348 3 mm M4 X 07 4 PLACES ea M3 5 X 0 6 4 PLACES 2X 5 52 SQ All dimensions are shown in millimeters 223 Chapter 8 Specifications To Calculate Total Measurement Error To Calculate Total Measurement Error Each specification includes correction factors which account for errors present due to operational limitations of the multimeter This section explains these errors and shows how to apply them to your measurements Refer to Interpreting Multimeter Specifications starting on page 226 to get a better understanding of the terminology used and to help you interpret the multimeter s specifications The multimeter s accuracy specifications are expressed in the form of reading of range In addition to the reading error and range error you may need to add additional errors for certain operating conditions Check the list below to make sure you include all measurement errors for a given functio
112. ditional characters are truncated e The calibration message is stored in non volatile memory and does not change when power has been off or after a remote interface reset e Front Panel Operation 4 MESSAGE CAL MENU read the cal message Remote Interface Operation CALibration STRing lt quoted string gt store the cal message The following command string shows how to store a calibration message CAL STR CAL 2 1 96 99 Chapter 3 Features and Functions Operator Maintenance Operator Maintenance This section describes how to replace the power line and current fuses If you need additional information about replacing parts or repairing the multimeter see the Service Guide To Replace the Power Line Fuse The power line fuse is located within the multimeter s fuse holder assembly on the rear panel see also page 15 See the rear panel of the multimeter for the proper fuse rating To replace the 250 mAT fuse order Agilent part number 2110 0817 To Replace the Current Input Fuses The front and rear current input terminals are protected by two series fuses The first fuse is a 3A 250 Vac fast blow fuse and is located on the rear panel To replace this fuse order Agilent part number 2110 0780 A WwW An WwW Front amp Rear S VM Zon Current 5 Mar O Aca 1u 300V pl pei oe With a small flatblade screwdriver push in on the fuse cap and rotate it counterclockwise Remove the fuse cap
113. ditioning components These errors are included in the instrument specifications Internal temperature changes due to self heating may cause additional error on lower ac voltage ranges The additional error will be less than 0 02 of reading and will generally dissipate within a few minutes System Speeds 11 12 Function or Range Change Autorange Time ASCII readings to RS 232 ASCII readings to GPIB Max Internal Trigger Rate Max External Trigger Rate to Memory Max Extemal Trigger Rate to GPIB RS 232 Slow ac filter sinewave input 2 Relative to calibration standards add 0 13 of range for sinewave input only 8 For1 kQ unbalance in LO lead when input dc level varies 10 settling delay Delay Auto Fast AC filter 5 sec lt 0 8 sec 50 sec 50 sec 50 sec 50 sec 50 sec 1 Specifications are for 1 hour warm up at 61 2 digits 3 20 overrange on all ranges except 750 Vac 3 A range 4 Specifications are for sinewave input gt 5 of range For inputs from 1 to 5 of range and lt 50 kHz add 0 1 of range additional error For 50 kHz to 100 kHz 5 750 Vac range limited to 100 kHz or 8x1 0 Volt Hz 6 Typically 30 of reading error at 1 MHz 7 For frequencies below 100 Hz slow AC filter specified 9 Maximum reading rates for 0 01 of ac step additional error Additional settling delay required For External Trigger or remote operation using default 11 Maximum useful limit with d
114. e request service bit in the status byte summary register No other bits are affected Performing a serial poll will not affect instrument throughput The IEEE 488 2 standard does not ensure synchronization between your bus controller program and the instrument Use the OPC command to guarantee that commands previously sent to the instrument have completed Executing a serial poll before a RST CLS or other commands have completed can cause previous conditions to be reported 137 Chapter 4 Remote Interface Reference The SCPI Status Model Using STB to Read the Status Byte The STB status byte query command is similar to a serial poll except it is processed like any other instrument command The STB command returns the same result as an IEEE 488 serial poll except that the request service bit bit 6 is not cleared if a serial poll has occurred The STB command is not handled automatically by the IEEE 488 bus interface hardware and the command will be executed only after previous commands have completed Polling is not possible using the STB command Using the STB command does not clear the status byte summary register To Interrupt Your Bus Controller Using SRQ e Send a bus device clear message e Clear the event registers with the CLS clear status command e Set the ESE standard event register and SRE status byte register enable masks e Send the OPC operation complete quer
115. e the stored value Front Panel Operation After enabling null you can edit the stored null value by pressing Shift gt Menu Recall Any previously stored value is replaced with the new value Turning on the menu does not disable the null operation the multimeter will resume taking measurements when you turn off the menu 2 NULL VALUE MATH MENU See also To Make Null Relative Measurements on page 38 Remote Interface Operation You can use the following commands to make null measurements Math must be enabled before you can store a value in the Null Register CALCulate FUNCtion NULL CALCulate STATe OFF ON CALCulate NULL OFFSet lt value gt MINimum MAXimum The following program segment shows the proper order that you should execute the commands to enable null and set an offset value CALC FUNC NULL CALC STAT ON CALC NULL OFFS 2 0 Chapter 3 Features and Functions Math Operations dB Measurements Each dB measurement is the difference between the input signal and a stored relative value with both values converted to dBm dB reading in dBm relative value in dBm Applies to dc voltage and ac voltage measurements only e The relative value is adjustable and you can set it to any value between 0 dBm and 200 00 dBm e The relative value is stored in volatile memory the value is cleared when power has been off after a remote interface reset or after a function change e The rel
116. e CAL MENU If you move across the commands level in the menu you will notice that the 2 CALIBRATE command is hidden if the multimeter is secured To unsecure the multimeter select the parameter level of the SECURED command enter the security code then press Menu Enter A000000 CODE When you go to the commands level in the CAL MENU again you will notice that the multimeter is unsecured Notice also that the 2 CALIBRATE command is no longer hidden and you can perform a calibration 1 UNSECURED Remote Interface Operation 96 CALibration SECure STATe OFF ON lt code gt To unsecure the multimeter send the above command with the same code used to secure For example CAL SEC STAT OFF HP034401 Chapter 3 Features and Functions Calibration Overview To Secure Against C alibration You can secure the multimeter against calibration either from the front panel or remote interface The multimeter is secured when shipped from the factory and the security code is set to HP034401 Make sure you have read the security code rules on page 95 before attempting to secure the multimeter e Front Panel Operation 1 UNSECURED If the multimeter is you go into the CAL CAL MENU unsecured you will see the above command when MENU To secure the multimeter select the parameter level of the UNSECURED command enter the secu
117. e FETCh command except readings are not buffered internally 114 Caution MEASure Example Chapter 4 Remote Interface Reference Simplified Programming Overview If you send two query commands without reading the response from the first and then attempt to read the second response you may receive some data from the first response followed by the complete second response To avoid this do not send a query command without reading the response When you cannot avoid this situation send a device clear before sending the second query command Using the INITiate and FETCh Commands The INITiate and FETCh commands provide the lowest level of control with the most flexibility of measurement triggering and reading retrieval Use the INITiate command after you have configured the multimeter for the measurement This changes the state of the triggering system from the idle state to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied after the INITiate command is received The readings are placed in the multimeter s internal memory up to 512 readings can be stored Readings are stored in memory until you are able to retrieve them Use the FETCh command to transfer the readings from the multimeter s internal memory to the multimeter s output buffer where you can read them into your bus controller The following program segment shows how to use t
118. e MEASure and CONFigure Commands MEASure CURRent AC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make an ac current measurement with the specified range and resolution The reading is sent to the output buffer For ac measurements resolution is actually fixed at 6 digits The resolution parameter only affects the front panel display MEASure RESistance lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make a 2 wire ohms measurement with the specified range and resolution The reading is sent to the output buffer MEASure FRESistance lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make a 4 wire ohms measurement with the specified range and resolution The reading is sent to the output buffer MEASure FREQuency lt ange gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make a frequency measurement with the specified range and resolution The reading is sent to the output buffer For frequency measurements the multimeter uses one range for all inputs between 3 Hz and 300 kHz With no input signal applied frequency measurements return 0 MEASure PERiod lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and make a period measurement with the specified range and resolution The reading is sent to the output buffer For period measurements the multimeter uses one range for all inputs
119. e Ray Corson Product Regulations Program Manager For further information please contact your local Agilent Technologies sales office agent or distributor Authorized EU representative Agilent Technologies Deutschland GmbH Herrenberger Stra e 130 D 71034 B blingen Germany Note Unless otherwise indicated this manual applies to all Serial Numbers The Agilent Technologies 34401A is a 64 digit high performance digital multimeter Its combination of bench top and system features makes this multimeter a versatile solution for your measurement needs now and in the future Convenient Bench Top Features e Highly visible vacuum fluorescent display e Built in math operations e Continuity and diode test functions e Hands free Reading Hold feature e Portable ruggedized case with non skid feet Flexible System Features e GPIB EEE 488 interface and RS 232 interface e Standard programming languages SCPI Agilent 3478A and Fluke 8840 e Reading rates up to 1000 readings per second e Storage for up to 512 readings e Limit testing with pass fail signals e Optional 34812A BenchLink Meter Software for Microsoft Windows Agilent 34401A Multimeter The Front Panel at a Glance O e hh Ia DCI ACI naw Period dB dBm ov ACV naw Freq Cont ra 3 Agi lent 34401A 61 2 Digit Multimeter N4W Sense Input Ratio Ref va Ftio Math Lo 0 0 Lo DCI ACI
120. e Reference Command Summary Measurement Configuration Commands continued SENSe VOLTage DC RESolution lt resolution gt MINimum MAXimum VOLTage DC RESolution Nimum MAXimum VOLTage AC RESolution lt resolution gt MINimum MAXimum VOLTage AC RESolution Nimum MAXimum CURRent DC RESolution lt resolution gt MINimum MAXimum CURRent DC RESolution Nimum MAXimum CURRent AC RESolution lt resolution gt MINimum MAXimum CURRent AC RESolution Nimum MAXimum RESistance RESolution lt resolution gt MINimum MAXimum RESistance RESolution Nimum MAXimum FRESistance RESolution lt resolution gt MINimum MAXimum FRESistance RESolution MINimum MAXimum SENSe VOLTage DC NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum VOLTage DC NPLCycles MINimum MAXimum CURRent DC NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum CURRent DC NPLCycles MINimum MAXimum RESistance NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum RESistance NPLCycles MINimum MAXimum FRESistance NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum FRESistance NPLCycles MINimum MAXimum SENSe FREQuency APERture 0 01 0 1 1 MINimum MAXimum SENSe SENSe FREQuency APERture PERiod APERture 0 01 0 1 1 MINimum MAXimum PERiod APERture MINimum MAXimum ZERO AUTO OFF ONCE ON ZERO AUTO INPut IMPedance AU IMPedance AU ROUTe TERMinal TO OFF ON TO s
121. e enabled before you can store a value to the Relative Register CALCulate FUNCtion DB CALCulate STATe OFF ON CALCulate DB REFerence lt value gt MINimum MAXimum dBm Measurements The dBm operation calculates the power delivered to a resistance referenced to 1 milliwatt dBm 10 x Log reading reference resistance 1 mW Applies to dc voltage and ac voltage measurements only 68 You can choose from 17 different reference resistance values The factory setting for the reference resistance is 6002 The choices are 50 75 93 110 124 125 135 150 250 300 500 600 800 900 1000 1200 or 8000 ohms The reference resistance is stored in non volatile memory and does not change when power has been off or after a remote interface reset Front Panel Operation After enabling dBm you can select a new reference resistance by pressing Shift gt Menu Recall Turning on the menu does not disable the dBm operation the multimeter will resume taking measurements when you turn off the menu 4 dBm REF R MATH MENU See also To Make dBm Measurements on page 41 Remote Interface Operation You can use the following commands to make dBm measurements CALCulate FUNCtion DBM CALCulate STATe OFF ON CALCulate DBM REFerence lt value gt MINimum MAXimum Chapter 3 Features and Functions Math Operations Limit Testing The limit test operation enables you to perform pass f
122. e multimeter determines an internal resolution based on a 3 Hz signal If you query the range the multimeter will respond with 3 Hz With no input signal applied frequency and period measurements return 0 e The range is fixed for continuity tests 1 kQ range and diode tests 1 Vdc range with 1 mA current source output e For ratio measurements the specified range applies to the signal connected to the Input terminals Autoranging is automatically selected for reference voltage measurements on the Sense terminals Ranging is local to the selected function This means that you can select the ranging method auto or manual for each function independently When manually ranging the selected range is local to the function the multimeter remembers the range when you switch between functions 61 Ranging continued Chapter 3 Features and Functions Measurement Configuration Front Panel Operation Use the front panel RANGE keys to select autoranging or manual ranging For frequency and period measurements from the front panel ranging applies to the signal s input voltage not its frequency See also To Select a Range on page 20 e Remote Interface Operation You can set the range using any of the 62 following commands CONFigure lt function gt lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF MFASure lt function gt lt range gt MIN MAX DEF lt
123. e necessary precautions to minimize thermocouple voltages and temperature variations in low level voltage measurements The best connections are formed using copper to copper crimped connections The table below shows common thermoelectric voltages for connections between dissimilar metals Copper to Approx uV TC Copper lt 0 3 Gold 0 5 Silver 0 5 Brass 3 Beryllium Copper 5 Aluminum 5 Kovar or Alloy 42 40 Silicon 500 Copper Oxide 1000 Cadmium Tin Solder 0 2 Tin Lead Solder 5 The Agilent 34401A s input terminals are copper alloy 198 Vs Rs Chapter 7 Measurement Tutorial Loading Errors dc volts Loading Errors dc volts Measurement loading errors occur when the resistance of the device under test DUT is an appreciable percentage of the multimeter s own input resistance The diagram below shows this error source Rs HI Vs ideal DUT voltage i i Rs DUT source resistance i Ideal Ri multimeter input resistance Vs Ri Meter 10 Mo or gt 10 Ga LOO Error 100 x Rs 1 i Rs F Ri To reduce the effects of loading errors and to minimize noise pickup you can set the multimeter s input resistance to greater than 10 GQ for the 100 mVdc 1 Vdc and 10 Vdc ranges The input resistance is maintained at 10 MQ for the 100 Vdc and 1000 Vdc ranges Leakage Current Errors The multimeter s input capacitance will charge up due to input bias currents whe
124. e number of the person to contact for a new calibration Stored in non volatile memory e You can record information in the calibration message only from the remote interface However you can read the message from either the front panel menu or the remote interface e The calibration message may contain up to 40 characters However the multimeter can display only 12 characters of the message on the front panel additional characters are truncated CALibration STRing Query the calibration message and return a quoted string CALibration VALue lt value gt Specify the value of the known calibration signal used by the calibration procedure CALibration VALue Query the present calibration value 147 Caution Chapter 4 Remote Interface Reference RS 232 Interface Configuration RS 232 Interface Configuration See also Remote Interface Configuration on page 91 in chapter 3 You connect the multimeter to the RS 232 interface using the 9 pin DB 9 serial connector on the rear panel The multimeter is configured as a DTE Data Terminal Equipment device For all communications over the RS 232 interface the multimeter uses two handshake lines DTR Data Terminal Ready on pin 4 and DSR Data Set Ready on pin 6 The following sections contain information to help you use the multimeter over the RS 232 interface The programming commands for RS 232 are listed on page 153 RS 232 Configuration Overview Config
125. e to the desired position ee LU Ly Bench top viewing positions Carrying position Chapter 1 Quick Start To Measure Voltage To Measure Voltage Ranges 100 mV 1V 10 V 100 V 1000 V 750 Vac Maximum resolution 100 nV on 100 mV range AC technique true RMS ac coupled HE Agilent 24407 mator 4WSoense Input A Ratio Ref Mao Ma AC or DC Voltage nerion ______ Math Lo DG AGI naw Porlod d dBm Power m 500Vpk 3A oev acy J aw Frea como no f Mi Max rma Le e T Oe 4Digt SDigh amp Digt Ana Hold x OOO Me tt z Recall Emer d Menu prof Ji To Measure Resistance Ranges 100 Q 1 KQ 10 kQ 100 kQ 1 MQ 10 MQ 100 MQ Maximum resolution 100 uQ on 100 ohm range aaaoia x Agilent yi Digit muttinater cy amv 10v Resistance Function Moth Dci ACI aw Period aB dBm Power s00Vp a nev av eal LJ cont nu MB J Met Wi BDigit Auto g 1 4 Wire lt gt A A S a Can Sense Lo On Olt CAT I 800 A Test Current a L naw 17 Chapter 1 Quick Start To Measure Current To Measure Current Ranges 10 mA dc only 100 mA dc only 1A 3A Maximum resolution 10 nA on 10 mA range AC technique true RMS ac coupled H 3440iA Agilent i Digit Mutimeter RAW Sense input A Ratio
126. e used to connect the multimeter to most computers or terminals e Verify that you have connected the interface cable to the correct serial port on your computer COM1 COM2 etc 152 Chapter 4 Remote Interface Reference RS 232 Interface Commands RS 232 Interface Commands Use the front panel I O MENU to select the baud rate parity and number of data bits see pages 163 and 164 for more information SYSTem LOCal Place the multimeter in the local mode for RS 232 operation All keys on the front panel are fully functional SYSTem REMote Place the multimeter in the remote mode for RS 232 operation All keys on the front panel except the LOCAL key are disabled It is very important that you send the S YSTem REMote command to place the multimeter in the remote mode Sending or receiving data over the RS 232 interface when not configured for remote operation can cause unpredictable results SYSTem RWLock Place the multimeter in the remote mode for RS 232 operation This command is the same as the SYSTem REMote command except that all keys on the front panel are disabled including the LOCAL key Ctrl C Clear the operation in progress over the RS 232 interface and discard any pending output data This is equivalent to the IEEE 488 device clear action over the GPIB interface 153 Chapter 4 Remote Interface Reference An Introduction to the SCPI Language An Introduction to the SCPI Language SCPI
127. e voltages above 300 VAC See IEC Measurement Category II Overvoltage Protection on the following page for further infor mation Protection Limits To avoid instru ment damage and the risk of elec tric shock do not exceed any of the Protection Limits defined in the following section Protection Limits The Agilent 34401A Digital Multimeter pro vides protection circuitry to prevent damage to the instrument and to protect against the danger of electric shock provided the Pro tection Limits are not exceeded To ensure safe operation of the instrument do not exceed the Protection Limits shown on the front and rear panel and defined as follows Q 4W Sense Input Ratio Ref VJ a 200V 1000V Max Max A i LO LO a o 3A 500Vpk Max rms A Front Rear CAT II 300V Rear Note The front panel terminals are shown above The rear panel terminals are identi cal The Front Rear switch selects the ter minal set to be used Do not operate this switch while signals are present on the front or rear terminals The current protec tion fuse is on the rear panel Input Terminal Protection Limits Protection Limits are defined for the input terminals Main Input HI and LO Terminals The HI and LO input terminals are used for voltage resistance frequency period and diode test measurements Two Protection Limits are defined for these terminals HI to LO Protection Limit The Protection Limit from H
128. efault settling delays defeated 12 Speeds are for 41 digits Delay 0 Display OFF and 219 Chapter 8 Specifications Frequency and Period Characteristics E Frequency and Period Characteristics Accuracy Specifications of reading 1 Temperature 24 Hour 2 90 Day 1 Year Coefficient C Function Range 3 Frequency 23 C 1 23T 5T 23 5C 0 C 18 C 28 C 55 C Frequency 100 mV 3 Hz 5 Hz 0 10 0 10 0 10 0 005 Period 4 to 5 Hz 10 Hz 0 05 0 05 0 05 0 005 750 V 10 Hz 40 Hz 0 03 0 03 0 03 0 001 40 Hz 300 kHz 0 006 0 01 0 01 0 001 Additional Low Frequency Errors of reading 4 Resolution Frequency 6 5 4 3 Hz 5 Hz 0 0 12 0 12 5 Hz 10 Hz 0 0 17 0 17 10 Hz 40 Hz 0 0 2 0 2 40 Hz 100 Hz 0 0 06 0 21 100 Hz 300 Hz 0 0 03 0 21 300 Hz 1 kHz 0 0 01 0 07 gt 1 kHz 0 0 0 02 Transfer Accuracy typical 0 0005 of reading Conditions Within 10 minutes and 0 5 C Within 10 of initial value Following a 2 hour warm up For inputs gt 1 kHz and gt 100 mV Using 6 digit slow resolution 1 second gate time Measurements are made using accepted metrology practices 220 Chapter 8 Specifications Frequency and Period Characteristics Measuring Characteristics Frequency and Period Measurement Method Reciprocal counting technique AC coupled input using the ac voltage measurement function Voltage Ranges Auto or manual ranging Gate
129. efinitions Questionable Data Register Decimal Bit Value 0 Voltage Overload 1 1 Current Overload 2 2 Not Used 4 3 Not Used 8 4 Not Used 16 5 Not Used 32 6 Not Used 64 7 Not Used 128 8 Not Used 256 9 Ohms Overload 512 10 Not Used 1024 11 Limit Fail LO 2048 12 Limit Fail HI 4096 13 Not Used 8192 14 Not Used 16384 15 Not Used 32768 Definition Range overload on dc volts ac volts frequency period diode or ratio function Range overload on dc or ac current function Always set to 0 Always set to 0 Always set to 0 Always set to 0 Always set to 0 Always set to 0 Always set to 0 Range overload on 2 wire or 4 wire ohms Always set to 0 Reading is less than lower limit in limit test Reading exceeds upper limit in limit test Always set to 0 Always set to 0 Always set to 0 142 Chapter 4 Remote Interface Reference The SCPI Status Model The questionable data event register is cleared when e You execute a CLS clear status command e You query the event register using STATus QUEStionable EVENt The questionable data enable register is cleared when e You turn on the power PSC does not apply e You execute the STATus PRESet command e You execute the STATus QUEStionable ENABle 0 command 143 Chapter 4 Remote Interface Reference Status Reporting Commands Status Reporting Commands SYSTem ERRor Query the multimeter s e
130. el ERROR annunciator turns on one or more command syntax or hardware errors have been detected A record of up to 20 errors is stored in the multimeter s error queue See chapter 5 Error Messages for a complete listing of the errors Errors are retrieved in first in first out FIFO order The first error returned is the first error that was stored When you have read all errors from the queue the ERROR annunciator turns off The multimeter beeps once each time an error is generated If more than 20 errors have occurred the last error stored in the queue the most recent error is replaced with 350 Too many errors No additional errors are stored until you remove errors from the queue If no errors have occurred when you read the error queue the multimeter responds with 0 No error The error queue is cleared when power has been off or after a CLS clear status command has been executed The RST reset command does not clear the error queue Front Panel Operation 3 ERROR SYS MENU If the ERROR annunciator is on press Shift lt Recall Menu to read the errors stored in the queue The errors are listed horizontally on the parameter level All errors are cleared when you go to the parameter level and then turn off the menu First error in queue Error code Remote Interface Operation SYSTem ERRor Reads one error from the error queue Errors have the follo
131. en a trigger event such as BUS or EXTernal will occur The MAV bit is set only after all specified measurements have completed when using the INITiate command followed by FETCh Readings are placed in the multimeter s internal memory when using INITiate Sending the FETCh command transfers readings stored in internal memory by the INITiate command to the multimeter s output buffer Therefore the MAV bit can only be set after all measurements have been completed Using OPC to Signal When Data is in the Output Buffer Generally it is best to use the operation complete bit bit 0 in the standard event register to signal when a command sequence is completed This bit is set in the register after an OPC command has been executed If you send OPC after a command which loads a message in the multimeter s output buffer either reading data or query data you can use the operation complete bit to determine when the message is available However if too many messages are generated before the OPC command executes sequentially the output buffer will fill and the multimeter will stop taking readings 139 Chapter 4 Remote Interface Reference The SCPI Status Model The Standard Event Register The standard event register reports the following types of instrument events power on detected command syntax errors command execution errors self test or calibration errors query errors or when an OPC command is exec
132. end C else if command 0 q for i 0 i lt strlen command i Wait for DSR and transmitter hold register empty while inportb LSR amp inportb MSR amp 0x20 outportb THR command i Send character if strpbrk command If query then get response c 0 do while int_buf_count amp amp kbhit putch c int_buf_out t int_buf_count if int_buf_out gt int_buf INT_BUF_size int_buf_out int_buf if kbhit if getch 0x19 send_ctlce if Y then send C c 0xa Terminate loop while c Oxa End if while command 0 q q to quit program outportb IER inportb IER amp Oxfe Disable UART interrupt outporthb MCR 0x1 Disable IRQ buffer DTR 1 Disable IRQ4 in 8259 interrupt controller register outportb INT_controller 1 inportb INT_controller l IRQ4_enab j setvect IRQ4_int oldvect Restore old interrupt vector return 0 Continued on next page gt 195 Chapter 6 Application Programs RS 232 Operation Using Turbo C RS 232 Operation Using Turbo C continued void interrupt int_char_in void enable if int_buf_count lt INT_BUF_size int_buf_int inportb RDR int_buf_count if int_buf_in gt int_buf INT_BUF_size 0 int_buf_ovfl else inportb RDR int_buf_ovfl 1
133. ent register are logically ORed together to form a single summary bit Enable registers are both readable and writable Querying an enable register will not clear it The CLS clear status command does not clear enable registers but it does clear the bits in the event registers The STATus PRESet command will clear the questionable data enable register To enable bits in an enable register you must write a decimal value which corresponds to the binary weighted sum of the bits you wish to enable in the register 134 11 12 15 af O MN Chapter 4 Remote Interface Reference The SCPI Status Model SCPI Status System Questionable Data Event Register Voltage Overload Current Overload Not Used Not Used Enable Register Not Used Not Used Not Used Not Used Not Used Ohms Overload Not Used Limit Test Fail LO Limit Test Fail HI Not Used Not Used Not Used STAT QUES EVEN STAT QUES ENAB Standard Event Event Register Operation Complete Not Used Query Error Device Error Execution Error Enable Register Command Error Not Used Power On ESR ESE lt value gt ESE D OR 0 Not Used Not Used Not Used 3 Questionable Data 4 Message Available Standard Event STAT QUES ENAB lt value gt Binary Weights o N 3 o D 2 2 2 2 24 2 2 2 Status Byte Summary Register Enable Register Request
134. ent to the front panel and return a quoted string DISPlay TEXT CLEar Clear the message displayed on the front panel 132 Chapter 4 Remote Interface Reference System Related Commands SYSTem BEEPer Issue a single beep immediately SYSTem BEEPer STATe OFF ON Disable or enable the front panel beeper Stored in non volatile memory When you disable the beeper the multimeter will not emit a tone when 1 anew minimum or maximum is found in a min max test 2 a stable reading is captured in reading hold 3 a limit is exceeded in a limit test 4 a forward biased diode is measured in the diode test function SYSTem BEEPer STATe Query the state of the front panel beeper Returns 0 OFF or 1 ON SYSTem ERRor Query the multimeter s error queue Up to 20 errors can be stored in the queue Errors are retrieved in first in first out FIFO order Each error string may contain up to 80 characters SYSTem VERSion Query the multimeter to determine the present SCPI version DATA POINts Query the number of readings stored in the multimeter s internal memory RST Reset the multimeter to its power on configuration TST Perform a complete self test of the multimeter Returns 0 if the self test is successful or 1 if it test fails IDN Read the multimeter s identification string be sure to dimension a string variable with at least 35 characters 133 Chapter 4 Remote
135. er Source TRIGger SOURce IMMediate TRIGger SOURce EXTernal TRIGger SOURce BUS Front panel Single key Trigger Delay TRIGger DELay Sample Annunciator Measurement Sample Sample Count 1 Trigger Count 1 72 Chapter 3 Features and Functions Triggering Trigger Source Choices You must specify the source from which the multimeter will accept a trigger From the front panel the multimeter will accept a single trigger a hardware trigger from the Ext Trig terminal or continuously take readings using auto trigger At power on auto triggering is used From the remote interface the multimeter will accept a software bus trigger a hardware trigger from the Ext Trig terminal or an immediate internal trigger The Q sample annunciator turns on during each measurement e The trigger source is stored in volatile memory the source is set to auto trigger front panel or immediate remote interface when power has been off or after a remote interface reset e To select the trigger source from the remote interface use the following command The CONFigure and MEASure commands automatically set the trigger source to IMMediate TRIGger SOURce BUS IMMediate EXTernal Auto Triggering In the auto trigger mode front panel only the multimeter continuously takes readings at the fastest rate possible for the present configuration This is the power on trigger source for front panel operati
136. er for measurements is by using the MEASure command However this command does not offer much flexibility When you execute the command the multimeter presets the best settings for the requested configuration and immediately performs the measurement You cannot change any settings other than function range and resolution before the measurement is taken The results are sent to the output buffer Sending the MEASure command is the same as sending a CONFigure command followed immediately by a READ command Using the CONFigure Command For a little more programming flexibility use the CONFigure command When you execute the command the multimeter presets the best settings for the requested configuration like the MEASure command However the measurement is not automatically started and you can change measurement parameters before making measurements This allows you to incrementally change the multimeter s configuration from the preset conditions The multimeter offers a variety of low level commands in the INPut SENSe CALCulate and TRIGger subsystems You can use the SENSe FUNCt ion command to change the measurement function without using MEASure or CONFigure Use the INITiate or READ command to initiate the measurement 113 Chapter 4 Remote Interface Reference Simplified Programming Overview Using the range and resolution Parameters With the MEASure and CONFigure commands you can sele
137. ers The INFinite parameter instructs the multimeter to continuously accept triggers you must send a device clear to return to the idle state Trigger count is ignored while in local operation MIN 1 MAX 50 000 Stored in volatile memory TRIGger COUNt MINimum MAXimum Query the trigger count If you specify an infinite trigger count the query command returns 9 90000000E 37 131 Chapter 4 Remote Interface Reference System Related Commands System Related Commands See also System Related Operations starting on page 84 in chapter 3 FETCh Transfer readings stored in the multimeter s internal memory by the INITiate command to the multimeter s output buffer where you can read them into your bus controller READ Change the state of the trigger system from the idle state to the wait for trigger state Measurements will begin when the specified trigger conditions are satisfied following the receipt of the READ command Readings are sent immediately to the output buffer DISPlay OFF ON Turn the front panel display off or on Stored in volatile memory DISPlay Query the front panel display setting Returns 0 OFF or 1 ON DISPlay TEXT lt quoted string gt Display a message on the front panel The multimeter will display up to 12 characters in a message any additional characters are truncated Stored in volatile memory DISPlay TEXT Query the message s
138. es and contact resistances are automatically reduced using this method Four wire ohms is often used in automated test applications where long cable lengths numerous connections or switches exist between the multimeter and the device under test The recommended connections for 4 wire ohms measurements are shown below See also To Measure Resistance on page 17 O p Veter Ideal ltest Meter 203 Chapter 7 Measurement Tutorial Removing Test Lead Resistance Errors Removing Test Lead Resistance Errors To eliminate offset errors associated with the test lead resistance in 2 wire ohms measurements follow the steps below 1 Short the ends of the test leads together The multimeter displays the test lead resistance 2 Press Null from the front panel The multimeter displays 0 ohms with the leads shorted together Power Dissipation Effects When measuring resistors designed for temperature measurements or other resistive devices with large temperature coefficients be aware that the multimeter will dissipate some power in the device under test If power dissipation is a problem you should select the multimeter s next higher measurement range to reduce the errors to acceptable levels The following table shows several examples DUT Range Test Current Power at Full Scale
139. esolution in the same units as the measurement function not in number of digits MIN selects the smallest value accepted which gives the most resolution MAX selects the largest value accepted which gives the least resolution Stored in volatile memory lt function gt RESolution MINimum MAXimum Query the resolution for the selected function For frequency or period measurements the multimeter returns a resolution setting based upon a 3 Hz input frequency lt function gt NPLCycles 0 02 0 2 1 10 100 MINimum MAXimum Select the integration time in number of power line cycles for the present function the default is 10 PLC This command is valid only for dc volts ratio dc current 2 wire ohms and 4 wire ohms MIN 0 02 MAX 100 Stored in volatile memory lt function gt NPLCycles MINimum MAXimum Query the integration time for the selected function FREQuency APERture 0 01 0 1 1 MINimum MAXimum Select the aperture time or gate time for frequency measurements the default is 0 1 seconds Specify 10 ms 41 digits 100 ms default 54 digits or 1 second 6 digits MIN 0 01 seconds MAX 1 second Stored in volatile memory FREQuency APERture MINimum MAXimum Query the aperture time for frequency measurements PERiod APERture 0 01 0 1 1 MINimum MAXimum Select the aperture time or gate time for period measurements the default is 0 1 seconds Specify 10 ms 41 digits 100 ms default 5 digi
140. eter s capabilities and operation 26 Chapter 2 Front Panel Menu Operation Front Panel Menu Reference Front Panel Menu Reference A MEASurement MENU 1 AC FILTER gt 2 CONTINUITY gt 3 INPUTR gt 4 RATIO FUNC gt 5 RESOLUTION 1 AC FILTER 2 CONTINUITY 3 INPUT R 4 RATIO FUNC 5 RESOLUTION B MATH MENU Selects the slow medium or fast ac filter Sets the continuity beeper threshold 1 Q to 1000 Q Sets the input resistance for dc voltage measurements Enables the dev dcv ratio function Selects the measurement resolution 1 MIN MAX gt 2 NULL VALUE gt 3 dB REL gt 4 dBm REFR gt 5 LIMIT TEST gt 6 HIGH LIMIT gt 7 LOW LIMIT MIN MAX NULL VALUE dB REL dBm REF R LIMIT TEST HIGH LIMIT LOW LIMIT NOOR ON C TRIGger MENU Recalls the stored minimum maximum average and reading count Recalls or sets the null value stored in the null register Recalls or sets the dBm value stored in the dB relative register Selects the dBm reference resistance value Enables or disables limit testing Sets the upper limit for limit testing Sets the lower limit for limit testing 1 READ HOLD gt 2 TRIG DELAY gt 3 N SAMPLES 1 READ HOLD 2 TRIG DELAY 3 N SAMPLES Sets the reading hold sensitivity band Specifies a time interval which is inserted before a measurement Sets the number of samples per trigger 27 Chapter 2 Front
141. eter in the wait for trigger state takes a reading when the Ext Trig terminal is pulsed and sends the reading to the multimeter s internal memory The FETCh command transfers the reading from internal memory to the output buffer CONF VOLT DC 10 0 003 TRIG SOUR EXT INIT FETC bus enter statement Storing readings in memory using the INITiate command is faster than sending readings to the output buffer using the READ command The multimeter can store up to 512 readings in internal memory If you configure the multimeter to take more than 512 readings using the sample count and trigger count and then send INITiate a memory error is generated After you execute an INITiate command no further commands are accepted until the measurement sequence is completed However if you select TRIGger SOURce BUS the multimeter will accept the TRG command bus trigger or an IEEE 488 Group Execute Trigger message 116 Chapter 4 Remote Interface Reference The MEASure and CONFigure Commands The MEASure and CONFigure Commands See also Measurement Configuration starting on page 51 in chapter 3 e For the range parameter MIN selects the lowest range for the selected function MAX selects the highest range DEF selects autoranging e For the resolution parameter specify the resolution in the same units as the measurement function not in number of digits MIN selects the smallest value accepted which gives
142. f 23 Chapter 1 Quick Start To Rack Mount the Multimeter HE Mallon 55 anne o o ooooo0oo0oo0O 2e O OSs 505000 O To rack mount a single instrument order adapter kit 5063 9240 Fe Mallen Piuse FE Meat ee O loe OOO0000 retatatatatate Qe To rack mount two instruments side by side order lock link kit 5061 9694 and flange kit 5063 9212 To install one or two instruments in a sliding support shelf order shelf 5063 9255 and slide kit 1494 0015 for a single instrument also order filler panel 5002 3999 24 Front Panel Menu Operation Front Panel Menu Operation By now you should be familiar with the FUNCTION and RANGE DIGITS groups of front panel keys You should also understand how to make front panel connections for the various types of measurements If you are not familiar with this information we recommend that you read chapter 1 Quick Start starting on page 11 This chapter introduces you to three new groups of front panel keys MENU MATH and TRIG You will also learn how to use the comma separator and store readings in memory This chapter does not give a detailed description of every front panel key or menu operation It does however give you a good overview of the front panel menu and many front panel operations See chapter 3 Features and Functions starting on page 49 for a complete discussion of the multim
143. f no readings are stored in memory EMPTY is displayed The stored readings are displayed with their units u m k etc when appropriate For example Reading number 10 31607K Exponent gt gt 11 Move across to view the two remaining stored readings The readings are stored horizontally on the parameter level If you press lt when you get to the parameter level you will see the last reading and you will know how many readings were stored On Off Shift lt 12 Turn off the menu EXITING MENU 48 Features and Functions Features and Functions You will find that this chapter makes it easy to look up all the details about a particular feature of the multimeter Whether you are operating the multimeter from the front panel or from the remote interface this chapter will be useful This chapter is divided into the following sections e Measurement Configuration starting on page 51 e Math Operations starting on page 63 Triggering starting on page 71 e System Related Operations starting on page 84 e Remote Interface Configuration starting on page 91 e Calibration Overview starting on page 95 e Operator Maintenance starting on page 100 e Power On and Reset State on page 101 Some knowledge of the front panel menu will be helpful before you read this chapter If you have not already read chapter 2 Front Panel Menu Operation
144. f or after a remote interface reset The beeper is enabled when the multimeter is shipped from the factory e Front Panel Operation 6 BEEP SYS MENU Remote Interface Operation SYSTem BEEPer issue a single beep immediately SYSTem BEEPer STATe OFF ON disable enable beeper state 88 Chapter 3 Features and Functions System Related Operations Comma Separators The multimeter can display readings on the front panel with or without a comma separator This feature is available only from the front panel 08 241 53 VDC 08 24153 VDC With comma separator factory setting Without comma separator e The display format is stored in non volatile memory and does not change when power has been off or after a remote interface reset The comma separator is enabled when the multimeter is shipped from the factory e Front Panel Operation 7 COMMA SYS MENU See also To Turn Off the Comma Separator on page 37 Firmware Revision Query The multimeter has three microprocessors for control of various internal systems You can query the multimeter to determine which revision of firmware is installed for each microprocessor e The multimeter returns three numbers The first number is the firmware revision number for the measurement processor the second is for the input output processor and the third is for the front panel processor e Front Panel Operation 8 REVISION SYS MENU REV
145. face reset e There are certain restrictions to be aware of when you are selecting the interface language see also Remote Interface Selection on page 92 The Agilent 3478A and Fluke 8840A 8842A languages are not supported on the RS 232 interface GPIB 488 RS 232 SCPI Language X xX 3478A Language xX Not allowed Fluke 8840A Language xX Not allowed e Front Panel Operation 5 LANGUAGE I O MENU See also To Select the Programming Language on page 165 e Remote Interface Operation LI select SCPI language L2 select Agilent 3478A language L3 select Fluke 8840A language 94 Chapter 3 Features and Functions Calibration Overview Calibration Overview This section gives a brief introduction to the calibration features of the multimeter For a more detailed discussion of the calibration procedures see chapter 4 in the Service Guide Calibration Security This feature allows you to enter a security code to prevent accidental or unauthorized calibrations of the multimeter When you first receive your multimeter it is secured Before you can calibrate the multimeter you must unsecure it by entering the correct security code e The security code is set to HP034401 when the multimeter is shipped from the factory The security code is stored in non volatile memory and does not change when power has been off or after a remote interface reset e To secure the multimeter from the remote in
146. g null measurements also called relative each reading is the difference between a stored null value and the input signal One possible application is in making more accurate two wire ohms measurements by nulling the test lead resistance Result reading null value Applies to all measurement functions except continuity diode and ratio e The null value is adjustable and you can set it to any value between 0 and 120 of the highest range for the present function e The null value is stored in volatile memory the value is cleared when power has been off after a remote interface reset or after a function change 65 Null Relative continued Chapter 3 Features and Functions Math Operations 66 The null value is stored in the multimeter s Null Register There are two ways you can specify the null value First you can enter a specific number into the register from the front panel menu or from the remote interface Any previously stored value is replaced with the new value If you are operating the multimeter from the front panel entering a null value also turns on the null function The second way to enter the null value is to let the multimeter store the first reading in the register After you enable null the first reading displayed will be zero if you have not changed the value stored in the register If you entered a number into the register as described in the paragraph above the first reading does not overwrit
147. gger State After you have configured the multimeter and selected a trigger source you must place the multimeter in the wait for trigger state A trigger will not be accepted until the multimeter is in this state If a trigger signal is present and if multimeter is in the wait for trigger state the measurement sequence begins and readings are taken The wait for trigger state is a term used primarily for remote interface operation From the front panel the multimeter is always in the wait for trigger state and will accept triggers at any time unless a measurement is already in progress You can place the multimeter in the wait for trigger state by executing any of the following commands from the remote interface MEASure READ INITiate The multimeter requires approximately 20 ms of set up time after you send a command to change to the wait for trigger state Any external triggers that occur during this set up time are ignored Halting a Measurement in Progress You can send a device clear at any time to halt a measurement in progress and place the multimeter in the idle state The following statement shows how to send a device clear over the GPIB interface using BASIC CLEAR 722 IEEE 488 Device Clear A device clear does not affect the configuration of the triggering system The trigger source sample count trigger delay and number of triggers are not changed 76 Chap
148. guage L2 select Agilent 3478A language L3 select Fluke 8840A language Virtually all of the commands available for the other two multimeters are implemented in the 34401A with the exception of the self test and calibration commands You must always calibrate the 34401A using the SCPI language setting The calibration commands from the other two multimeters will not be executed Be aware that measurement timing may be different in the alternate language compatibility modes Agilent 3478A Language Setting All Agilent 3478A commands are accepted and executed by the 34401A with equivalent operations with the exception of the commands shown below Refer to your Agilent 3478A Operating Manual for further remote interface programming information 3478A Command Description Agilent 34401A Action C Perform a calibration Command is accepted but is ignored Device Clear Perform a self test and reset Self test is not executed 166 Chapter 4 Remote Interface Reference Alternate Programming Language Compatibility Fluke 8840A 8842A Language Setting All Fluke 8840A or 8842A commands are accepted and executed by the Agilent 34401A with equivalent operations with the exception of the commands shown below Refer to your Fluke 8840A or 8842A Instruction Manual for further remote interface programming information Fluke 8840A Command Description Agilent 34401A Action G2 GET calibration input prompt Generate
149. guage Version Query 90 Remote Interface Configuration GPIB Address 91 Remote Interface Selection 92 Baud Rate Selection RS 232 93 Parity Selection RS 232 93 Programming Language Selection 94 Calibration Calibration Security 95 Calibration Count 98 Calibration Message 99 Operator Maintenance To Replace the Power Line Fuse 100 To Replace the Current Input Fuses 100 Power On and Reset State 101 Contents Chapter 4 Remote Interface Reference Command Summary 105 Simplified Programming Overview 112 The MEASure and CONFigure Commands 117 Measurement Configuration Commands 121 Math Operation Commands 124 Triggering 127 Triggering Commands 130 System Related Commands 132 The SCPI Status Model 134 Status Reporting Commands 144 Calibration Commands 146 RS 232 Interface Configuration 148 RS 232 Interface Commands 153 An Introduction to the SCPI Language 154 Output Data Formats 159 Using Device Clear to Halt Measurements 160 TALK ONLY for Printers 160 To Set the GPIB Address 161 To Select the Remote Interface 162 To Set the Baud Rate 163 To Set the Parity 164 To Select the Programming Language 165 Alternate Programming Language Compatibility 166 SCPI Compliance Information 168 IEEE 488 Compliance Information 169 U9 U09 Chapter 5 Error Messages Execution Errors 173 Self Test Errors 179 Calibration Errors 180 Chapter 6 Application Programs Using MEASure for a Single Measurement 185 Using C
150. he MEASure command to make a measurement This example configures the multimeter for dc voltage measurements automatically places the multimeter in the wait for trigger state internally triggers the multimeter to take one reading and then sends the reading to the output buffer MEAS VOLT DC 10 0 003 bus enter statement This is the simplest way to take a reading However you do not have any flexibility with MEASure to set the trigger count sample count trigger delay etc All measurement parameters except function range and resolution are preset for you automatically see the table on page 112 115 CONFigure Example CONFigure Example Chapter 4 Remote Interface Reference Simplified Programming Overview The following program segment shows how to use the READ command with CONFigure to make an externally triggered measurement The program configures the multimeter for dc voltage measurements CONF igure does not place the multimeter in the wait for trigger state The READ command places the multimeter in the wait for trigger state takes a reading when the Ext Trig terminal is pulsed and sends the reading to the output buffer CONF VOLT DC 10 0 003 TRIG SOUR EXT READ bus enter statement The following program segment is similar to the program above but it uses INITiate to place the multimeter in the wait for trigger state The INITiate command places the multim
151. hen a command sequence is completed For more information see The SCPI Status Model starting on page 134 The example is shown in BASIC and QuickBASIC see page 190 GPIB Operation Using BASIC 10 REAL Aver Min_rdg Max_rdg 20 INTEGER Val Hpib Mask Task 30 ASSIGN Dmm TO 722 40 CLEAR 7 Clear GPIB and dmm 50 OUTPUT Dmm RST Reset dmm 60 OUTPUT Dmm CLS Clear dmm status registers 70 OUTPUT Dmm ESE 1 Enable operation complete bit to set standard event bit in status byte 80 OUTPUT Dmm SRE 32 Enable standard event bit in status byte to pull the IEEE 488 SRQ line 90 OUTPUT Dmm OPC Assure synchronization 100 ENTER Dmm Val TIO 1 120 Configure the multimeter to make measurements T304 140 OUTPUT Dmm CONF VOLT DC 10 Set dmm to 10 volt dc range 150 OUTPUT Dmm VOLT DC NPLC 10 Set the integration time to 10 PLCs 160 OUTPUT Dmm TRIG COUN 100 Dmm will accept 100 triggers 170 OUTPUT Dmm CALC FUNC AVER STAT ON Select min max and enable math 180 OUTPUT Dmm INIT Place dmm in wait for trigger state 190 OUTPUT Dmm OPC Set operation complete bit in standard event registers when measurement is complete 200 210 Hpib 7 220 ON INTR Hpib GOSUB Read_data 230 ask 2 Bit 1 is SRO 240 ENABLE INTR Hpib Mask Enable SRQ to inter
152. hows how to program an AT personal computer for interrupt driven COM port communications SCPI commands can be sent to the Agilent 34401A and responses received for commands that query information The following program is written in Turbo C and can be easily modified for use with Microsoft Quick C RS 232 Operation Using Turbo C Continued on next page gt include lt bios h gt include lt stdio h gt include lt string h gt include lt dos h gt include lt conio h gt define EVEN_7 0x18 0x02 0x04 Even parity 7 data 2 stop define ODD_7 0x08 0x02 0x04 Odd parity 7 data 2 stop define NONE_8 0x00 0x03 0x04 None parity 8 data 2 stop define BAUD300 0x40 define BAUD600 0x60 define BAUD1200 0x80 define BAUD2400 OxA0 define BAUD4800 0xC0 define BAUD9600 OxEO 8250 UART Registers define CO Ox3F8 COM1 base port address define THR COM 0 LCR bit 7 0 define RDR COM 0 LCR bit 7 0 define IER COM 1 LCR bit 7 0 define IIR COM 2 The rest are don t care for bit 7 define LCR COM 3 define MCR COM 4 define LSR COM 5 define MSR COM 6 Microsoft is a U S registered trademark of Microsoft Corporation 193 Chapter 6 Application Programs RS 232 Operation Using Turbo C RS 232 Operation Using Turbo C continued define IRQ4 int OxC IRQ4 interrupt vector number define IRQ4
153. ibration changing security code 98 commands 146 count 98 errors 180 message 99 secure procedure 97 security code factory setting 95 unsecure procedure 96 carrying handle adjusting 16 removing 23 chassis ground 5 CLEAR 76 comma separator 37 89 command compliance SCPD 168 summary 105 111 syntax conventions 50 105 155 common commands 169 common mode rejection CMR 201 complete self test 13 86 CONFigure 118 119 preset state 110 Conformity Declaration 237 connections 2 wire ohms 17 4 wire ohms 17 ac current 18 ac volts 17 continuity 19 de current 18 de volts 17 dev dev ratio 44 diode 19 frequency 18 period 18 connectors Ext Trig 5 83 GPIB interface 5 RS 232 interface 5 VM Comp 5 83 continuity connections 19 current source 19 math functions allowed 63 124 threshold resistance 52 crest factor error 207 224 current ac current connections 18 math functions allowed 63 124 ranges 18 signal filter 51 214 de current connections 18 math functions allowed 63 124 measurement errors 205 ranges 18 current input fuses replacing 100 current source continuity 19 diode 19 231 Index D DATA FEED 65 126 130 DATA FEED 65 126 130 DATA POINts 84 133 data logging to printer 91 160 data types SCPD 158 data formats output 159 dB measurements description 40 67 front panel 40 functions allowed 63 124 relative value 40
154. imple seven step sequence Place the multimeter in a known state often the reset state Change the multimeter s settings to achieve the desired configuration Set up the triggering conditions Initiate or arm the multimeter for a measurement Trigger the multimeter to make a measurement Retrieve the readings from the output buffer or internal memory Read the measured data into your bus controller SrO OTIR UD a The MEASure and CONFigure commands provide the most straight forward method to program the multimeter for measurements You can select the measurement function range and resolution all in one command The multimeter automatically presets other measurement parameters ac filter autozero trigger count etc to default values as shown below MEASure and CONFigure Preset States Command MEASure and CONFigure Setting AC Filter DET BAND 20 Hz medium filter Autozero ZERO AUTO OFF if resolution setting results in NPLC lt 1 ON if resolution setting results in NPLC gt 1 Input Resistance INP IMP AUTO OFF fixed at 10 MQ for all dc voltage ranges Samples per Trigger SAMP COUN 1 sample Trigger Count TRIG COUN 1 trigger Trigger Delay TRIG DEL Automatic delay Trigger Source TRIG SOUR Immediate Math Function CALCulate subsystem OFF 112 Chapter 4 Remote Interface Reference Simplified Programming Overview Using the MEASure Command The easiest way to program the multimet
155. ing table shows the range error applied to the multimeter s 24 hour dc voltage specification Range Error Range Range Input Level of range Error Voltage 10 Vde 10 Vdc 0 0004 lt 40 uV 10 Vdc 1 Vdc 0 0004 lt 40 uV 10 Vdc 0 1 Vdc 0 0004 lt 40 uV Total Measurement Error To compute the total measurement error add the reading error and range error You can then convert the total measurement error to a percent of input error or a ppm part per million of input error as shown below Total Measurement Error x 100 Kop inpun err Input Signal Level Total Measurement Error ppm of input error x 1 000 000 Input Signal Level Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range Compute the total measurement error using the 90 day accuracy specifications 0 0020 of reading 0 0005 of range Reading Error 0 0020 x 5 Vdc 100 uV Range Error 0 0005 x 10 Vdc 50 uV Total Error 100V 50 V 150V 0 0030 of 5 Vdc 30 ppm of 5 Vdc 225 Chapter 8 Specifications Interpreting Multimeter Specifications Interpreting Multimeter Specifications This section is provided to give you a better understanding of the terminology used and will help you interpret the multimeter s specifications Number of Digits and Overrange The number of digits specification is the most fundamental and sometimes the most confusing characteristic of
156. ing the input terminals on the rear panel See The Front Panel at a Glance on page 2 for the location of the front rear switch The input terminals can only be configured from the front panel You cannot select the terminals from the remote interface but you can query the present setting e The Rear annunciator turns on when you select the rear terminals e Remote Interface Operation You can query the multimeter to determine whether the front or rear input terminals are selected ROUTe TERMinals returns FRON or REAR 58 Chapter 3 Features and Functions Measurement Configuration Autozero When autozero is enabled default the multimeter internally disconnects the input signal following each measurement and takes a zero reading It then subtracts the zero reading from the preceding reading This prevents offset voltages present on the multimeter s input circuitry from affecting measurement accuracy When autozero is disabled the multimeter takes one zero reading and subtracts it from all subsequent measurements It takes a new zero reading each time you change the function range or integration time Applies to dc voltage dc current and 2 wire ohms measurements only Autozero is enabled when you select 4 wire ohms or ratio measurements e The autozero mode is stored in volatile memory the multimeter automatically enables autozero when power has been off or after a remote interface reset e Fro
157. iode 19 frequency 18 period 18 Z zero measurements 59 213
158. is stored in non volatile memory and does not change when power has been off or after a remote interface reset 163 On Off Shift lt Auto Man ENTER Chapter 4 Remote Interface Reference To Set the Pa rity To Set the Parity You can select the parity for RS 232 operation The multimeter is configured for even parity with 7 data bits when shipped from the factory See also Parity Selection on page 93 1 Turn on the front panel menu A MEAS MENU 2 Move across to the I O MENU choice on this level E I O M ENU 3 Move down a level and then across to the PARITY command 4 PARITY 4 Move down to the parameter level to select the parity Use the left right arrow keys to see the parity choices Choose from one of the following When you set None 8 data bits Even 7 data bits or Odd 7 data bits parity you are indirectly setting the number of data bits EVEN 7 BITS 5 Save the change and turn off the menu The parity selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset 64 On Off Shift lt Auto Man ENTER Chapter 4 Remote Interface Reference To Select the Programming Language To Select the Programming Language You can select one of three languages to program the multime
159. kBASIC The following example shows how to send command instructions and receive command responses over the RS 232 interface using QuickBASIC RS 232 Operation Using QuickBASIC CLS LOCATE 1 1 DIM cmd 100 resp 1000 Set up serial port for 9600 baud even parity 7 bits Ignore Request to Send and Carrier Detect Send line feed enable parity check reserve 1000 bytes for input buffer OPEN com1 9600 e 7 2 rs cd lf pe FOR RANDOM AS 1 LEN 1000 r r Put the multimeter into the remote operation mode PRINT 1 SYST REM r Query the multimeter s id string r PRINT 1 IDN LINE INPUT 1 resp RINT IDN returned resp td ig Ask what revision of SCPI the multimeter conforms to PRINT 1 SYST VERS LINE INPUT 1 resp PRI SYST VERS returned resp za Send a message to the multimeter s display and generate a beep PRINT 1 SYST BEEP DISP TEXT 34401Aa T r Configure the multimeter for dc voltage readings 0 V range 0 1 V resolution 4 readings PRINT 1 CONF VOLT DC 10 0 1 SAMP COUN 4 Trigger the readings and fetch the results PRINT 1 READ LINE INPUT 1 resp PRI READ returned resp END m 7 192 Chapter 6 Application Programs RS 232 Operation Using Turbo C RS 232 Operation Using Turbo C The following example s
160. l ranging applies to the signal s input voltage not its frequency e The range is fixed for continuity 1 KQ range and diode 1 Vdc range Ranging is local to the selected function This means that you can select the ranging method auto or manual for each function independently When manually ranging the selected range is local to the function the multimeter remembers the range when you switch between functions 20 Chapter 1 Quick Start To Set the Resolution To Set the Resolution You can set the display resolution to 41 514 or 614 digits either to optimize measurement speed or noise rejection In this book the most significant digit leftmost on the display is referred to as the digit since it can only be a 0 or 1 4 Digit 5 Digit 6 Digit Ue A putes Man Press the Shift key Selects 41 2 digits Selects 51 2 digits Selects 61 digits most noise rejection e The resolution is set to 5 digits at power on and after a remote interface reset The resolution is fixed at 5 digits for continuity and diode tests e You can also vary the number of digits displayed using the arrow keys however the integration time is not changed Fewer More Digits Digits Resolution is local to the selected function This means that you can select the resolution for each function independently The multimeter remembers the resolution when you switch between f
161. le on the rear panel You should also make sure that the power source you plugged the multimeter into is energized 2 Verify the power line voltage setting The line voltage is set to the proper value for your country when the multimeter is shipped from the factory Change the voltage setting if it is not correct The settings are 100 120 220 or 240 Vac for 230 Vac operation use the 220 Vac setting See the next page if you need to change the line voltage setting 3 Verify that the power line fuse is good The multimeter is shipped from the factory with a 250 mA fuse installed This is the correct fuse for all line voltages See the next page if you need to replace the power line fuse To replace the 250 mAT fuse order Agilent part number 2110 0817 14 Chapter 1 Quick Start If the Multimeter Does Not Turn On 1 Remove the power cord Remove the 2 Remove the line voltage selector from fuse holder assembly from the rear panel the assembly See rear panel for proper fuse rating Agilent Part Number 2110 0817 250 mAT 3 Rotate the line voltage selector until the correct voltage appears in the window 100 120 220 230 or 240 Vac Verify that the correct line voltage is selected and the power line fuse is good 15 Chapter 1 Quick Start To Adjust the Carrying Handle To Adjust the Carrying Handle To adjust the position grasp the handle by the sides and pull outward Then rotate the handl
162. ller asserts the DSR line TRUE to allow the multimeter to complete the transmission You can break the interface deadlock by sending the lt Ctrl C gt character which clears the operation in progress and discards pending output this is equivalent to the IEEE 488 device clear action For the lt C rl C gt character to be recognized reliably by the multimeter while it holds DTR FALSE the controller must first set DSR FALSE In addition you may have difficulty sending the lt Ctrl C gt character if you are interrupting a query operation in which case the multimeter hold the DTR line FALSE This may prevent the controller from sending anything unless you first reprogram the interface to ignore DTR RS 232 Troubleshooting Here are a few things to check if you are having problems communicating over the RS 232 interface If you need additional help refer to the documentation that came with your computer e Verify that the multimeter and your computer are configured for the same baud rate parity and number of data bits Make sure that your computer is set up for 1 start bit and 2 stop bits these values are fixed on the multimeter e Make sure to execute the SYSTem REMote command to place the multimeter in the REMOTE mode e Verify that you have connected the correct interface cable and adapters Even if the cable has the proper connectors for your system the internal wiring may not be correct The Agilent 34398A Cable Kit can b
163. lly understood and met A WARNING notice denotes a hazard It calls attention to an operating procedure practice or the like that if not correctly per formed or adhered to could result in personal injury or death Do not proceed beyond a WARNING notice until the indicated condi tions are fully understood and met 34401A User s Guide Safety Information General Do not use this product in any manner not specified by the manufacturer The protec tive features of this product may be impaired if it is used in a manner not speci fied in the operation instructions Do not install substitute parts or perform any unauthorized modification to the prod uct Return the product to an Agilent Tech nologies Sales and Service Office for service and repair to ensure that safety features are maintained Ground the Instrument If your product is provided with a ground ing type power plug the instrument chassis and cover must be connected to an electri cal ground to minimize shock hazard The ground pin must be firmly connected to an electrical ground safety ground terminal at the power outlet Any interruption of the protective grounding conductor or discon nection of the protective earth terminal will cause a potential shock hazard that could result in personal injury Cleaning Clean the outside of the instrument with a soft lint free slightly dampened cloth Do not use detergent or chemical solvents 34401
164. ltimeter you must unsecure it by entering the correct security code CALibration COUNt Query the multimeter to determine the number of times it has been calibrated Your multimeter was calibrated before it left the factory When you receive your multimeter read the count to determine its initial value Stored in non volatile memory e The calibration count increments up to a maximum of 32 767 after which it wraps around to 0 Since the value increments by one for each calibration point a complete calibration will increase the value by many counts CALibration SECure CODE lt new code gt Enter a new security code To change the security code you must first unsecure the multimeter using the old security code and then enter a new code The calibration code may contain up to 12 characters Stored in non volatile memory CALibration SECure STATe OFF ON lt code gt Unsecure or secure the multimeter for calibration The calibration code may contain up to 12 characters Stored in non volatile memory CALibration SECure STATe Query the secured state of the multimeter Returns 0 OFF or 1 ON 146 Chapter 4 Remote Interface Reference Calibration Commands CALibration STRing lt quoted string gt Record calibration information about your multimeter For example you can store such information as the last calibration date the next calibration due date the instrument serial number or even the name and phon
165. measuring ac voltages less than 100 mV be aware that these measurements are especially susceptible to errors introduced by extraneous noise sources An exposed test lead will act as an antenna and a properly functioning multimeter will measure the signals received The entire measurement path including the power line act as a loop antenna Circulating currents in the loop will create error voltages across any impedances in series with the multimeter s input For this reason you should apply low level ac voltages to the multimeter through shielded cables You should connect the shield to the input LO terminal Make sure the multimeter and the ac source are connected to the same electrical outlet whenever possible You should also minimize the area of any ground loops that cannot be avoided A high impedance source is more susceptible to noise pickup than a low impedance source You can reduce the high frequency impedance of a source by placing a capacitor in parallel with the multimeter s input terminals You may have to experiment to determine the correct capacitor value for your application Most extraneous noise is not correlated with the input signal You can determine the error as shown below Voltage Measured y Vin 24 Noise 2 Correlated noise while rare is especially detrimental Correlated noise will always add directly to the input signal Measuring a low level signal with the same frequency as the local power line is a common
166. meter Specifications Resolution Resolution is the numeric ratio of the maximum displayed value divided by the minimum displayed value on a selected range Resolution is often expressed in percent parts per million ppm counts or bits For example a 614 digit multimeter with 20 overrange capability can display a measurement with up to 1 200 000 counts of resolution This corresponds to about 0 0001 1 ppm of full scale or 21 bits including the sign bit All four specifications are equivalent Accuracy Accuracy is a measure of the exactness to which the multimeter s measurement uncertainty can be determined relative to the calibration reference used Absolute accuracy includes the multimeter s relative accuracy specification plus the known error of the calibration reference relative to national standards such as the U S National Institute of Standards and Technology To be meaningful the accuracy specifications must be accompanied with the conditions under which they are valid These conditions should include temperature humidity and time There is no standard convention among multimeter manufacturers for the confidence limits at which specifications are set The table below shows the probability of non conformance for each specification with the given assumptions Specification Probability Criteria of Failure Mean 2 sigma 4 5 Mean 3 sigma 0 3 Mean 4 sigma 0 006 Variations in performance fr
167. mmand does not initiate the measurement For ac measurements resolution is actually fixed at 6 digits The resolution parameter only affects the front panel display CONFigure CURRent DC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for dc current measurements with the specified range and resolution This command does not initiate the measurement CONFigure CURRent AC lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for ac current measurements with the specified range and resolution This command does not initiate the measurement For ac measurements resolution is actually fixed at 6 digits The resolution parameter only affects the front panel display CONFigure RESistance lt unge gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for 2 wire ohms measurements with the specified range and resolution This command does not initiate the measurement CONFigure FRESistance lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure the multimeter for 4 wire ohms measurements with the specified range and resolution This command does not initiate the measurement 119 Chapter 4 Remote Interface Reference The MEASure and CONFigure Commands CONFigure FREQuency lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF Preset and configure a frequency me
168. n Also make sure you apply the conditions as described in the footnotes on the specification pages e Ifyou are operating the multimeter outside the 23 C 5 C temperature range specified apply an additional temperature coefficient error e For dc voltage dc current and resistance measurements you may need to apply an additional reading speed error or autozero OFF error e For ac voltage and ac current measurements you may need to apply an additional low frequency error or crest factor error Understanding the of reading Error The reading error compensates for inaccuracies that result from the function and range you select as well as the input signal level The reading error varies according to the input level on the selected range This error is expressed in percent of reading The following table shows the reading error applied to the multimeter s 24 hour dc voltage specification Reading Error Reading Range Input Level of reading Error Voltage 10 Vde 10 Vde 0 0015 lt 150 uV 10 Vdc 1 Vdc 0 0015 lt 15uV 10 Vdc 0 1 Vdc 0 0015 lt 1 5 uV 224 Error Example Chapter 8 Specifications To Calculate Total Measurement Error Understanding the of range Error The range error compensates for inaccuracies that result from the function and range you select The range error contributes a constant error expressed as a percent of range independent of the input signal level The follow
169. n the terminals are open circuited if the input resistance is 10 GQ The multimeter s measuring circuitry exhibits approximately 30 pA of input bias current for ambient temperatures from 0 C to 30 C Bias current will double x2 for every 8 C change in ambient temperature above 30 C This current generates small voltage offsets dependent upon the source resistance of the device under test This effect becomes evident for a source resistance of greater than 100 kQ or when the multimeter s operating temperature is significantly greater than 30 C ib multimeter bias current Rs DUT source resistance Ci multimeter input capacitance For DCV ranges Meter 100V 1000V Ci lt 50 pF For all ACV ranges lt 50 pF l O et nh g a 0 1V 1V 10V Ci lt 700 pF i Error v ib X Rs 199 Chapter 7 Measurement Tutorial Rejecting Power Line Noise Voltages Rejecting Power Line Noise Voltages A desirable characteristic of integrating analog to digital A D converters is their ability to reject spurious signals Integrating techniques reject power line related noise present with dc signals on the input This is called normal mode rejection or NMR Normal mode noise rejection is achieved when the multimeter measures the average of the input by integrating it over a fixed period If you set the integration time to a whole number of power line cycles PLCs of the spurious input
170. ndard Event Request Service Not Used Serial Poll SPOLL SRE lt vaiue gt STB SRE Output Buffer ae on Operation Complete PSC 0 1 Not Used PSC Query Error Device Error f Execution Error OR Command Error SRE lt enable value gt ae SRE Power On ESR ESE lt value gt ESE STB Calibration Commands see page 146 for more information CALibration CALibration COUNt CALibration SECure CODE lt new code gt SECure STATe OFF ON lt code gt SECure STATe CALibration STRing lt quoted string gt STRing CALibration VALue lt value gt Default parameters are shown in bold 110 Chapter 4 Remote Interface Reference Command Summary RS 232 Interface Commands see page 148 for more information SYSTem LOCal SYSTem REMote SYSTem RWLock IEEE 488 2 Common Commands see page 169 for more information CLS ESE lt enable value gt ESE ESR IDN OPC OPC PSC 0 1 PSC RST SRE lt enable value gt SRE STB TRG TOL Default parameters are shown in bold 111 First time SCPI users see page 154 Chapter 4 Remote Interface Reference Simplified Programming Overview Simplified Programming Overview You can program the multimeter to take measurements from the remote interface using the following s
171. ng second 10 readings second e The ac filter selection is stored in volatile memory the multimeter selects the medium filter 20 Hz when power has been off or after a remote interface reset e Front Panel Operation Select from the menu the slow filter 3 Hz medium filter 20 HZ or fast filter 200 Hz The default is the medium filter 1 AC FILTER MEAS MENU e Remote Interface Operation Specify the lowest frequency expected in the input signal The multimeter selects the appropriate filter based on the frequency you specify see table above The CONFigure and MEASure commands select the 20 Hz filter DETector BANDwidth 3 20 200 MINimum MAXimum 51 Chapter 3 Features and Functions Measurement Configuration Continuity Threshold Resistance When measuring continuity the multimeter emits a continuous tone if the measured resistance is less than the threshold resistance You can set the threshold to any value between 1 Q and 1000 Q The threshold resistance is adjustable only from the front panel e The threshold resistance is stored in non volatile memory and does not change when power has been off or after a remote interface reset e The factory setting for the threshold resistance is 10 Q e After enabling the continuity function you can select a different threshold resistance by pressing Shift gt Menu Recall 2 CONTINUITY MEAS MENU A0010 OHM See also
172. ng languages and IEEE 488 interface cards provide access to this capability through their own unique commands The status registers the error queue and all configuration states are left unchanged when a device clear message is received Device clear performs the following actions e All measurements in progress are aborted e The multimeter returns to the trigger idle state e The multimeter s input and output buffers are cleared e The multimeter is prepared to accept a new command string For RS 232 operation sending the lt Ctrl C gt character will perform the equivalent operations of the IEEE 488 device clear message The multimeter s DTR data terminal ready handshake line will be true following a device clear message See DTR DSR Handshake Protocol on page 151 for further details TALK ONLY for Printers You can set the address to 31 which is the talk only mode In this mode the multimeter can output readings directly to a printer without being addressed by a bus controller over either GPIB or RS 232 For proper operation make sure your printer is configured in the listen always mode Address 31 is not a valid address if you are operating the multimeter from the GPIB interface with a bus controller If you select the RS 232 interface and then set the GPIB address to the talk only address 31 the multimeter will send readings over the RS 232 interface when in the local mode 160 On Off
173. nt Panel Operation The autozero mode is set indirectly when you set the resolution Resolution Choices Integration Time Autozero Fast 4 Digit 0 02 PLC Off Slow 4 Digit 1 PLC On Fast 5 Digit 0 2 PLC Off Slow 5 Digit default 10 PLC On Fast 6 Digit 10 PLC On Slow 6 Digit 100 PLC On These settings configure the multimeter just as if you had pressed the corresponding DIGITS keys from the front panel Remote Interface Operation The OFF and ONCE parameters have a similar effect Autozero OFF does not issue a new zero measurement Autozero ONCE issues an immediate zero measurement N ERO AUTO OFF ONCE ON 59 Autozero continued Chapter 3 Features and Functions Measurement Configuration The following table shows the relationship between integration time and autozero settings from the remote interface and the corresponding front panel settings Remote Configuration From 34401A Specifications NPLC 100 Autozero On Digits Displayed 61 NPLC 100 Autozero Off Digits Displayed 61 NPLC 10 Autozero On NPLC 10 Autozero Off Digits Displayed 612 NPLC 1 Autozero On NPLC 1 Autozero Off Digits Displayed 51 2 Front Panel Equivalent Digits Displayed Readings Sec Slow 6 digits N A N A Digits Displayed 67 N A 6 0 6 Fast 6 digits N A N A Slow 5 digits Digits Displayed 612 aS N A 6 6 Slow 4 digits N A N A Digits Displa
174. nt Rdg END ae ol oe 185 Chapter 6 Application Programs Using CONFigure with a Math Operation Using CONFigure with a Math Operation The following example uses CONFigure with the dBm math operation The CONFigure command gives you a little more programming flexibility than the MEASure command This allows you to incrementally change the multimeter s configuration The example is shown in BASIC and QuickBASIC see next page GPIB Operation Using BASIC 10 DIM Rdgs 1 5 20 ASSIGN Dmm TO 722 30 CLEAR 7 Clear GPIB and dmm 40 OUTPUT Dmm RST Reset dmm 50 OUTPUT Dmm CLS Clear dmm status registers 60 OUTPUT Dmm CALC DBM REF 50 50 ohm reference resistance 70 OUTPUT Dmm CONF VOLT AC 1 0 001 Set dmm to 1 amp ac range 80 OUTPUT Dmm DET BAND 200 Select 200 Hz fast ac filter 90 OUTPUT Dmm TRIG COUN 5 Dmm will accept 5 triggers 100 OUTPUT Dmm TRIG SOUR IMM Trigger source is IMMediate 110 OUTPUT Dmm CALC FUNC DBM Select dBm function 120 OUTPUT Dmm CALC STAT ON Enable math 130 OUTPUT Dmm READ Take readings send to output buffer 140 E ER Dmm Rdgs 150 PRINT USING K Rdgs 160 END 186 Chapter 6 Application Programs Using CONFigure with a Math Operation GPIB Operation Using QuickBASI
175. nt by executing SAMP COUN You can also query the minimum or maximum count allowed as follows SAMP COUN MIN SAMP COUN MAX If you send two query commands without reading the response from the first and then attempt to read the second response you may receive some data from the first response followed by the complete second response To avoid this do not send a query command without reading the response When you cannot avoid this situation send a device clear before sending the second query command SCPI Command Terminators A command string sent to the multimeter must terminate with a lt new line gt character The IEEE 488 EOI end or identify message is interpreted as a lt new line gt character and can be used to terminate a command string in place of a lt new line gt character A lt carriage return gt followed by a lt new line gt is also accepted Command string termination will always reset the current SCPI command path to the root level 157 Chapter 4 Remote Interface Reference An Introduction to the SCPI Language l E E E 488 2 Common Commands The IEEE 488 2 standard defines a set of common commandes that perform functions like reset self test and status operations Common commands always begin with an asterisk are four to five characters in length and may include one or more parameters The command keyword is separated from the first parameter by a blank space Use a semicolon
176. nutes and 0 5 C Within 10 of initial value Following a 2 hour warm up Fixed range between 10 and 100 of full scale Using 62 digit slow resolution 100 PLC Measurements are made using accepted metrology practices 216 Chapter 8 Specifications DC Characteristics Measuring Characteristics DC Voltage Measurement Method A D Linearity Input Resistance 0 1 V 1 V 10 V ranges 100 V 1000 V ranges Input Bias Current Input Terminals Input Protection Continuously integrating multi slope III A D converter 0 0002 of reading 0 0001 of range Selectable 10 MQ or gt 10 GQ 11 10 MQ 1 lt 30 pA at 25 C Copper alloy 1000 V on all ranges Resistance Measurement Method Max Lead Resistance 4 wire ohms Input Protection Selectable 4 wire or 2 wire ohms Current source referenced to LO input 10 of range per lead for 100 Q 1 kQ ranges 1 kQ per lead on all other ranges 1000 V on all ranges DC Current Shunt Resistor Input Protection 0 12 for 1A 3A 52 for 10 mA 100 mA Externally accessible 3A 250 V fuse Internal 7A 250 V fuse Continuity Diode Test Response Time 300 samples sec with audible tone Continuity Threshold Adjustable from 1 Q to 1000 Q DC DC Ratio Measurement Method Input HI LO Reference HI LO Input HI LO 100 mV to 1000 V ranges Reference Hl Input LO Input to Reference 100 mV to 10 V ranges autoranged Reference LO to Input LO vol
177. of the input signal can dramatically affect measurement accuracy A common way to describe signal waveshapes is crest factor Crest factor is the ratio of the peak value to RMS value of a waveform For a pulse train for example the crest factor is approximately equal to the square root of the inverse of the duty cycle as shown in the table on the previous page In general the greater the crest factor the greater the energy contained in higher frequency harmonics All multimeters exhibit measurement errors that are crest factor dependent Crest factor errors for the Agilent 34401A are shown in the specifications in chapter 8 Note that the crest factor errors do not apply for input signals below 100 Hz when using the slow ac filter 207 Crest Factor continued Example Chapter 7 Measurement Tutorial Crest Factor Errors non sinusoidal inputs You can estimate the measurement error due to signal crest factor as shown below Total Error Error sine Error crest factor Error bandwidth Error sine error for sinewave as shown in chapter 8 Error crest factor crest factor additional error as shown in chapter 8 Error bandwidth estimated bandwidth error as shown below C F2 F C F signal crest factor Bandwidth Error TMR K F input fundamental frequency 4n x BW BW multimeter s 3 dB bandwidth 1 MHz for the Agilent 34401A Calculate the approximate measurement error for a pulse train input with
178. om reading to reading and instrument to instrument decrease for increasing number of sigma for a given specification This means that you can achieve greater actual measurement precision for a specific accuracy specification number The Agilent 34401A is designed and tested to meet performance better than mean 4 sigma of the published accuracy specifications 227 Chapter 8 Specifications Interpreting Multimeter Specifications Transfer Accuracy Transfer accuracy refers to the error introduced by the multimeter due to noise and short term drift This error becomes apparent when comparing two nearly equal signals for the purpose of transferring the known accuracy of one device to the other 24 Hour Accuracy The 24 hour accuracy specification indicates the multimeter s relative accuracy over its full measurement range for short time intervals and within a stable environment Short term accuracy is usually specified for a 24 hour period and for a 1 C temperature range 90 Day and 1 Year Accuracy These long term accuracy specifications are valid for a 23 C 5 C temperature range These specifications include the initial calibration errors plus the multimeter s long term drift errors Temperature Coefficients Accuracy is usually specified for a 23 C 5 C temperature range This is a common temperature range for many operating environments You must add additional temperature coefficient errors to the accuracy s
179. ommand summary 105 111 compatibility 166 compliance SCP 168 restrictions 92 94 selecting 94 165 pushbuttons front panel 2 Q questionable data register bit definitions 142 clearing 143 R rack mounting bumpers removing 23 carrying handle removing 23 filler panel kit 24 flange kit 24 lock link kit 24 sliding shelf kit 24 ranges 2 wire ohms 17 4 wire ohms 17 ac current 18 ac volts 17 dc current 18 de volts 17 dev dev ratio 44 frequency 18 period 18 Index ranging autoranging 20 61 front panel keys 20 overload 61 142 selecting 20 ratio dev dev measurements connections 44 front panel 44 math functions allowed 63 124 selecting 45 READ 114 130 reading hold beeper control 88 description 43 82 front panel 43 sensitivity band 43 82 reading memory functions allowed 46 84 number of readings stored 84 retrieving readings 46 storing readings 46 readings number of 77 rear panel input terminals 5 pictorial overview 5 rear terminals query setting 58 123 selecting 58 reciprocal counting technique 213 register diagram status 135 regulatory requirements 237 relative value dB 40 67 relative measurements description 38 65 front panel 38 functions allowed 63 124 Null Register 38 66 null test lead resistance 38 65 204 remote interface GPIB connector 5 GPIB selection 92 162 language restrictions 92 94 RS 232 connector 5 150 RS 232
180. on Single Triggering In the single trigger mode front panel only you can manually trigger the multimeter by pressing Single The multimeter takes one reading or the specified number of readings sample count each time you press the key The Trig annunciator turns on when the multimeter is waiting for a trigger The front panel Single key is disabled when in remote 73 Chapter 3 Features and Functions Triggering External Triggering In the external trigger mode the multimeter will accept a hardware trigger applied to the Ext Trig terminal The multimeter takes one reading or the specified number of readings sample count each time Ext Trig receives a low true pulse See also External Trigger Terminal on page 83 e The multimeter buffers one external trigger This means that if the multimeter is taking a reading and another external trigger occurs that trigger is accepted a Trigger ignored error is not reported After the reading in progress is complete the stored trigger satisfies the trigger source and then the trigger is issued e Front Panel Operation The external trigger mode is like the single trigger mode except that you apply the trigger to the Ext Trig terminal Pressing Single to enable the single trigger mode also enables the external trigger mode The Trig annunciator turns on when the multimeter is waiting for an external trigger The front panel Single key is disable
181. or over the remote interface Remote Interface Reference Chapter 4 contains reference information to help you program the multimeter over the remote interface Error Messages Chapter 5 lists the error messages that may appear as you are working with the multimeter Each listing contains enough information to help you diagnose and solve the problem Application Programs Chapter 6 contains several remote interface application programs to help you develop programs for your measurement application Measurement Tutorial Chapter 7 discusses measurement considerations and techniques to help you obtain the best accuracies and reduce sources of measurement error Specifications Chapter 8 lists the multimeter s specifications and describes how to interpret these specifications If you have questions relating to the operation of the Agilent 34401A call 1 800 452 4844 in the United States or contact your nearest Agilent Sales Office If your 34401A fails within one year of purchase Agilent will repair or replace it free of charge Call 1 877 444 7278 Agilent Express in the United States or contact your nearest Agilent Sales Office Contents Chapter 1 Quick Start To Prepare the Multimeter for Use 13 If the Multimeter Does Not Turn On 14 To Adjust the Carrying Handle 16 To Measure Voltage 17 To Measure Resistance 17 To Measure Current 18 To Measure Frequency or Period 18 To Test Continuity 19 To Check Diode
182. or 10 00 of reading e The sensitivity band is stored in volatile memory the multimeter sets the band to 0 10 of reading when power has been off or after a remote interface reset 43 Chapter 2 Front Panel Menu Operation To Make dev dcv Ratio Measurements To Make dev dev Ratio Measurements To calculate a ratio the multimeter measures a dc reference voltage applied to the Sense terminals and the voltage applied to the Input terminals dc signal voltage dc reference voltage Ratio To enable ratio measurements use the MEAS menu r 3 Agilent Sit Dist Natmete NAW Sense Ratio Ref RERRERREERE E p N Signal Reference my Voltage Voltage rinin Matth as r a oci ACI nw Period d dBm ocev acv aw Fwa comm now Min oe pes 4 Digit 6 Digit Digt Auto Hold OCUA WG E a Rear L onsort Recall FEN Enter Local cari tov AY ees HHH Ratio annunciator is on when ratio measurements are enabled e At the Sense terminals the reference voltage measurement function is always dc voltage and has a maximum measurable input of 12 Vdc Autoranging is automatically selected for reference voltage measurements on the Sense terminals e The Input LO and Sense LO terminals must have a common reference and cannot have a voltage difference greater than 2 volts e The specified measurement range applies only to the signal connected to the Input te
183. ors hold down the Shift key as you turn on the multimeter The Rear Panel at a Glance i Q 4W Sonso Va TON 101 d j XS Ratio Ret 300V reig 5 TO o yy Un 45 440 Hz 26VA Mex oo 0207127 ao 240v 220 220 230v ila VM Comp Ext Trig Front amp Ri ront amp Rear Fuse 250V 260mAT Current Input aX Faso CAT II 300V BV Max to RS 232 HHH e 1 Chassis Ground 5 Voltmeter Complete Output Terminal 2 Power Line Fuse Holder Assembly 6 External Trigger Input Terminal 3 Power Line Voltage Setting 7 GPIB IEEE 488 Interface connector 4 Front and Rear Current Input Fuse 8 RS 232 interface connector Use the front panel Input Output Menu to Select the GPIB or RS 232 interface see chapter 4 Set the GPIB bus address see chapter 4 Set the RS 232 baud rate and parity see chapter 4 In This Book Quick Start Chapter 1 prepares the multimeter for use and helps you get familiar with a few of its front panel features Front Panel Menu Operation Chapter 2 introduces you to the front panel menu and describes some of the multimeter s menu features Features and Functions Chapter 3 gives a detailed description of the multimeter s capabilities and operation You will find this chapter useful whether you are operating the multimeter from the front panel
184. other high impedance low dielectric absorption wire insulation for these measurements Specifications are for 1 hour warm up at 6 digits Relative to calibration standards 20 overrange on all ranges except 1000 Vdc 3 A range Specifications are for 4 wire ohms function or 2 wire ohms using Math Null Without Math Null add 0 2 Q additional error in 2 wire ohms function 5 For 1 kQ unbalance in LO lead 6 For power line frequency 0 1 7 For power line frequency 1 subtract 20 dB For 3 subtract 30 dB 8 Readings speeds for 60 Hz and 50 Hz operation Autozero Off 9 Speeds are for 41 digits Delay 0 Autozero OFF and Display OFF Includes measurement and data transfer over GPIB Add 20 uV for dc volts 4 pA for de current or 20 ma for resistance For these ranges inputs beyond 17V are clamped through 100 kQ typical OND 10 11 Chapter 8 Specifications AC Characteristics E AC Characteristics Accuracy Specifications of reading of range 1 Temperature 24 Hour 2 90 Day 1 Year Coefficient C Function Range 3 Frequency 23 C 1 23 C 5 23 C 5C 0CT 18 28 55 C True RMS 100 0000 mV 3Hz 5 Hz 1 00 0 03 1 00 0 04 1 00 0 04 0 100 0 004 AC Voltage 5 Hz 10 Hz 0 35 0 03 0 35 0 04 0 35 0 04 0 035 0 004 4 10 Hz 20 kHz 0 04 0 03 0 05 0 04 0 06 0 04 0 005 0 004 20 kHz 50 kHz 0 10 0 05 0 11 0 05 0 12 0 05
185. ou turn off the menu by pressing Shift lt Menu On Off or a front panel function math key You did not edit any values on the parameter level and changes were NOT saved NOT ENTERED You will see this message if you turn off the menu by pressing Shift lt Menu On Off or a front panel function math key You did some editing of parameters but the changes were NOT saved Press Auto Man Menu Enter to save changes made on the parameter level NOT RELEVANT The selected math operation is NOT valid for the function in use 30 Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial Menu Example 1 The following steps show you how to turn on the menu move up or Shift down between levels move across the choices on each level and turn off the menu In this example you will turn off the front panel beeper On Off lt 1 Turn on the menu You enter the menu on the menus level The MEAS MENU is your first choice on this level A MEAS MENU gt Vv Vv 2 Move across to the SYS MENU choice on this level There are six menu group choices available on the menus level Each choice has a letter prefix for easy identification A B etc D SYS MENU 3 Move down to the commands level within the SYS MENU The RDGS STORE command is your first choice on this level 1 RDGS STORE 31
186. oving 23 hardware rack mounting 24 hardware handshake RS 232 151 HP IB See GPIB l identification string 89 idle trigger state 76 129 IDN 89 IEEE 488 GPIB address displayed at power on 13 factory setting 91 setting the 91 161 TALK ONLY mode 91 160 compliance information 168 connector location 5 selecting interface 92 162 induced voltages 201 INITiate 115 130 input bias current 199 INPut IMPedance AUTO 58 123 input message terminators 157 input resistance dc volts 53 input signal range frequency 18 period 18 input terminals Front Rear switch 2 58 query setting 58 input message terminators 157 integration time definition 57 vs autozero 59 60 vs resolution 54 57 59 interface remote GPIB connector 5 GPIB selection 92 162 language restrictions 92 94 RS 232 connector 5 150 RS 232 selection 92 162 internal reading memory functions allowed 46 84 number of readings stored 84 retrieving readings 46 storing readings 46 internal triggering 75 L L1 L2 L3 94 166 language command summary 105 111 compatibility 166 compliance SCPD 168 restrictions 92 94 selecting 94 162 lead resistance 38 65 204 leakage current errors 199 limit test beeper control 88 description 69 functions allowed 63 124 RS 232 pass fail outputs 70 service request 69 142 line frequency noise 57 line voltage factory setting 14 selector module 15 setting the 15
187. pecification if you are operating the multimeter outside a 23 C 5 C temperature range the specification is per C 228 Chapter 8 Specifications Configuring for Highest Accuracy Measurements Configuring for Highest Accuracy Measurements The measurement configurations shown below assume that the multimeter is in its power on or reset state It is also assumed that manual ranging is enabled to ensure proper full scale range selection DC Voltage DC Current and Resistance Measurements e Set the resolution to 6 digits you can use the 6 digits slow mode for further noise reduction e Set the input resistance to greater than 10 GQ for the 100 mV 1 V and 10 V ranges for the best dc voltage accuracy e Use 4 wire ohms for the best resistance accuracy e Use Math Null to null the test lead resistance for 2 wire ohms and to remove interconnection offset for dc voltage measurements AC Voltage and AC Current Measurements e Set the resolution to 6 digits e Select the slow ac filter 3 Hz to 300 kHz Frequency and Period Measurements e Set the resolution to 6 digits 229 230 Index If you have questions relating to the operation of the multimeter call 1 800 452 4844 in the United States or contact your nearest Agilent Sales Office ly digit 21 54 2 wire ohms See two wire ohms 34398A Cable Kit 149 34399A Adapter Kit 149 3478A compatibility 166 34812A BenchLink Software 1 4 wire ohms
188. ple READ 10 Missing parameter Fewer parameters were received than expected for the command You omitted one or more parameters that are required for this command Example SAMP COUN 173 112 113 121 123 124 131 138 148 Chapter 5 Error Messages Execution Errors Program mnemonic too long A command header was received which contained more than the maximum 12 characters allowed Example CONFIGURATION VOLT DC Undefined header A command was received that is not valid for this multimeter You may have misspelled the command or it may not be a valid command If you are using the short form of the command remember that it may contain up to four letters Example TRIGG COUN 3 Invalid character in number An invalid character was found in the number specified for a parameter value Example STAT QUES ENAB B01010102 Numeric overflow A numeric parameter was found whose exponent was larger than 32 000 Example TRIG COUN 1534000 Too many digits A numeric parameter was found whose mantissa contained more than 255 digits excluding leading zeros Invalid suffix A suffix was incorrectly specified for a numeric parameter You may have misspelled the suffix Example TRIG DEL 0 5 SECS Suffix not allowed A suffix was received following a numeric parameter which does not accept a suffix Example SAMP COUN 1 SEC SEC is not a valid suffix Character data not allowed A disc
189. r ac current is larger due to the multimeter s series inductance and your measurement connections The burden voltage increases as the input frequency increases Some circuits may oscillate when performing current measurements due to the multimeter s series inductance and your measurement connections 212 Chapter 7 Measurement Tutorial Frequency and Period Measurement Errors Frequency and Period Measurement Errors The multimeter uses a reciprocal counting technique to measure frequency and period This method generates constant measurement resolution for any input frequency The multimeter s ac voltage measurement section performs input signal conditioning All frequency counters are susceptible to errors when measuring low voltage low frequency signals The effects of both internal noise and external noise pickup are critical when measuring slow signals The error is inversely proportional to frequency Measurement errors will also occur if you attempt to measure the frequency or period of an input following a dc offset voltage change You must allow the multimeter s input dc blocking capacitor to fully settle before making frequency measurements Making High Speed DC and Resistance Measurements The multimeter incorporates an automatic zero measurement procedure autozero to eliminate internal thermal EMF and bias current errors Each measurement actually consists of a measurement of the input terminals followed by a mea
190. rete parameter was received but a character string or a numeric parameter was expected Check the list of parameters to verify that you have used a valid parameter type Example DISP TEXT ON 174 151 158 160 to 168 170 to 178 211 213 214 Chapter 5 Error Messages Execution Errors Invalid string data An invalid character string was received Check to see if you have enclosed the character string in single or double quotes and that the string contains valid ASCII characters Example DISP TEXT ON the ending quote is missing String data not allowed A character string was received but is not allowed for the command Check the list of parameters to verify that you have used a valid parameter type Example CALC STAT ON Block data errors The multimeter does not accept block data Expression errors The multimeter does not accept mathematical expressions Trigger ignored A Group Execute Trigger GET or TRG was received but the trigger was ignored Make sure the multimeter is in the wait for trigger state before issuing a trigger and make sure the correct trigger source is selected Init ignored An INITiate command was received but could not be executed because a measurement was already in progress Send a device clear to halt a measurement in progress and place the multimeter in the idle state Trigger deadlock A trigger deadlock occurs when the trigger source is BU
191. rity code then press Menu Enter A000000 CODE When you go to the commands level in the CAL MENU again you will notice that the multimeter is secured Notice also that the 2 CALIBRATE command is now hidden and you cannot perform a calibration 1 SECURED e Remote Interface Operation CALibration S ECure STATe OFF ON lt code gt To secure the multimeter send the above command with the same code as used to unsecure For example CAL SEC STAT ON HP034401 97 Calibration Security continued Chapter 3 Features and Functions Calibration Overview To Change the Security Code To change the security code you must first unsecure the multimeter and then enter a new code Make sure you have read the security code rules on page 95 before attempting to secure the multimeter e Front Panel Operation To change the security code first make sure that the multimeter is unsecured Select the parameter level of the UNSECURED command enter the new security code then press Menu Enter Changing the code from the front panel also changes the code as seen from the remote interface e Remote Interface Operation CALibration SECure CODE lt new code gt To change the security code first unsecure the multimeter using the old security code Then enter the new code For example CAL SEC STAT OFF HP034401 unsecure with old code CAL SEC CODE 22010443 enter new
192. rminals The signal on the Input terminals can be any dc voltage up to 1000 volts 44 On Off Shift lt Auto Man ENTER Chapter 2 Front Panel Menu Operation To Make dcev dcv Ratio Measurements The following steps show you how to select the ratio function using the front panel menu 1 Turn on the menu A MEAS MENU 2 Move down a level and then across to the RATIO FUNC command 4 RATIO FUNC 3 Move down to the parameter level For this command there is only one choice on this level DCV DCV 4 Select the ratio function and turn off the menu Notice that the Ratio annunciator turns on CHANGE SAVED To disable ratio measurements select a different measurement function by pressing any front panel function key 45 Single On Off Shift lt Chapter 2 Front Panel Menu Operation To Use Reading Memory To Use Reading Memory The multimeter can store up to 512 readings in internal memory The following steps demonstrate how to store readings and retrieve them Select the function Select any measurement function You can also select Null Min Max dB dBm or limit test You can change the function at any time during reading memory Select the single trigger mode Notice that the Trig annunciator turns on When reading memory is enabled readings are stored when you trigger the multimeter
193. rned on when power has been off or after a remote interface reset e Front Panel Operation After enabling min max you can read the stored minimum maximum average and count by pressing Shift gt Menu Recall Turning on the menu does not disable the min max operation the multimeter will resume taking measurements when you turn off the menu 1 MIN MAX MATH MENU See also To Store Minimum and Maximum Readings on page 39 64 Chapter 3 Features and Functions Math Operations e Remote Interface Operation You can use the following commands to make min max measurements CALCulate FUNCtion AVERage CALCulate STATe OFF ON CALCulate AVERage MINimum read the minimum value CALCulate AVERage MAXimum read the maximum value CALCulate AVERage AVERage read the average of all readings CALCulate AVERage COUNt read the count A new command is available starting with firmware Revision 2 which allows you to take readings using INITiate without storing them in internal memory This command may be useful with the min max operation since it allows you to determine the average of a series of readings without storing the individual values DATA FEED RDG_STORE do not store readings DATA FEED RDG_STORE CALCulate store readings default See page 126 for more information on using the DATA FEED command Null Relative Operation When makin
194. ronment Rack Dimensions HxWxD Weight Safety EMC Vibration and Shock Warranty 100 V 120 V 220 V 240 V 410 45 Hz to 66 Hz and 360 Hz to 440 Hz Automatically sensed at power on 25 VA peak 10 W average Full accuracy for 0 C to 55 C Full accuracy to 80 R H at 40 C 40 C to 70 C 88 5 mm x 212 6 mm x 348 3 mm 3 6 kg 8 Ibs See Delcaration of Conformity See Declaration of Conformity MIL T 28800E Type III Class 5 data on file 1 year standard Triggering and Memory Reading HOLD Sensitivity 0 01 0 1 1 or 10 of reading Samples per Trigger 1 to 50 000 Trigger Delay 0 to 3600 sec 10 us step size External Trigger Delay lt 1ms External Trigger Jitter lt 500 us Memory 512 readings Math Functions Null Min Max Average dB dBm Limit Test with TTL output dBm reference resistances 50 75 93 110 124 125 135 150 250 300 500 600 800 900 1000 1200 or 8000 ohms Standard Programming Languages SCPI Standard Commands for Programmable Instruments Agilent 3478A Language Emulation Fluke 8840A Fluke 8842A Language Emulation Accessories Included Test Lead Kit with probes alligator and grabber attachments User s Guide Service Guide test report and power cord 222 Remote Interface GPIB IEEE 488 1 IEEE 488 2 and RS 232C This ISM device complies with Canadian ICES 001 Cet appareil ISM est conforme a la norme NMB 001 du Cana
195. ront Panel Menu Tutorial Lv 5 Move down to edit the NULL VALUE parameter The null value should be 0 0 Vde when you come to this point in the menu for the first time For this example you will set the null value to 2 0 volts A000 000 mvVDC OD When you see the flashing A on the left side of the display you can abort the edit and return to the commands level by pressing a 6 Make the number negative The leftmost character on the display toggles between and 000 000 mvVDC gt 7 Move the flashing cursor over to edit the first digit Notice that the leftmost digit is flashing 000 000 mvDC a A 8 Increment the first digit until 2 is displayed You decrement or increment each digit independently Neighboring digits are not affected 200 000 mvVDC 35 Chapter 2 Front Panel Menu Operation A Front Panel Menu Tutorial lt lt 9 Move the flashing cursor over to the units location Notice that the units are flashing on the right side of the display 200 000 mVDC a 10 Increase the displayed number by a factor of 10 Notice that the position of the decimal point changes and the displayed number increases by a factor of 10 2 000 00 VDC Auto Man 11 Save the change and turn off the menu ENTER The multimeter beeps and displays a message to show that the change is now in effect You are then exited from the menu CH
196. ront panel menu A MEAS MENU 2 Move across to the I O MENU choice on this level E I O MENU 3 Move down a level and then across to the INTERFACE command 2 INTERFACE 4 Move down to the parameter level to select the interface Use the left right arrow keys to see the interface choices Choose from the following HP IB 488 or RS 232 HP IB 488 5 Save the change and turn off the menu The interface selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset 62 On Off Shift lt Auto Man ENTER Chapter 4 Remote Interface Reference To Set the Ba ud Rate To Set the Baud Rate You can select one of six baud rates for RS 232 operation The rate is set to 9600 baud when the multimeter is shipped from the factory See also Baud Rate Selection on page 93 1 Turn on the front panel menu A MEAS MENU 2 Move across to the I O MENU choice on this level E I O M ENU 3 Move down a level and then across to the BAUD RATE command 3 BAUD RATE 4 Move down to the parameter level to select the baud rate Use the left right arrow keys to see the baud rate choices Choose from one of the following 300 600 1200 2400 4800 or 9600 baud 9600 BAUD 5 Save the change and exit the menu The baud rate selection
197. rror queue Up to 20 errors can be stored in the queue Errors are retrieved in first in first out FIFO order Each error string may contain up to 80 characters STATus QUEStionable ENABle lt enable value gt Enable bits in the Questionable Data enable register The selected bits are then reported to the Status Byte STATus QUEStionable ENABle Query the Questionable Data enable register The multimeter returns a binary weighted decimal representing the bits set in the enable register STATus QUEStionable EVENt Query the Questionable Data event register The multimeter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register STATus PRESet Clear all bits in the Questionable Data enable register CLS Clear the Status Byte summary register and all event registers ESE lt enable value gt Enable bits in the Standard Event enable register The selected bits are then reported to the Status Byte ESE Query the Standard Event enable register The multimeter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register 144 Chapter 4 Remote Interface Reference Status Reporting Commands ESR Query the Standard event register The multimeter returns a decimal value which corresponds to the binary weighted sum of all bits set in the register OPC Sets the operation complete bit bit 0 in the Standard Event register after
198. rupt the program 250 260 Execute other tasks while waiting for data 270 Continued on next page gt 188 Chapter 6 Application Programs Using the Status Registers GPIB Operation Using BASIC continued 280 Task 1 290 WHILE Task 1 300 DISP Taking Readings 310 WAIT 5 320 DISP 330 WAIT 5 340 END WHILE 350 DISP AVE Aver MIN Min_rdg MAX Max_rdg 360 STOP 370 380 Read_data 390 OUTPUT Dmm CALC AVER AVER MIN MAX Read the average min and max 400 ER Dmm Aver Min_rdg Max_rdg 410 OUTPUT Dmm CLS Clear dmm status registers 420 Task 0 430 RETURN 440 END 189 Chapter 6 Application Programs Using the Status Registers GPIB Operation Using QuickBASIC EM S Include QBSetup SC amp 7 EV amp 722 FO1 RST ENGTH1 LEN INF0O1 FO2 CLS E H2 LEN INFO2S FO3 ESE 1 E H3 LEN INFO3 FO4S SRE 32 E H4 LEN INF0O4 FO5 0PC H5 LEN INFO5 6 CONF VOLT DC 10 H6 LEN INFO6 7 VOLT DC NPLC 10 H7 LEN INFO7S 8S TRIG COUN 100 H8 LEN INFO8S nj nj nj QONOCONONOQNOCONOQNONONONONQNOQ Ea EAEE E EE E a E EA E E Ea EEA EA VER EAE eE EE E A t FO9 CALC FUNC AVER STAT ON E H9 LEN INFO9 FO10 INIT E H10 LEN
199. s CONFigure lt fimction gt lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF MEASure lt function gt lt range gt MIN MAX DEF lt resolution gt MIN MAX DEF lt function gt RESolution lt resolution gt MIN MAX Specify the resolution in the same units as the measurement function not in number of digits For example for dc volts specify the resolution in volts For frequency specify the resolution in hertz CONF VOLT DC 10 0 001 4 digits on the 10 Vdc range MEAS CURR AC 1 1E 6 6 digits on the 1 A range CONF FREQ 1 KHZ 0 1 Hz 1000 Hz input 0 1 Hz resolution VOLT AC RES 0 05 50 mV resolution on the ac function 56 Chapter 3 Features and Functions Measurement Configuration Integration Time Integration time is the period during which the multimeter s analog to digital A D converter samples the input signal for a measurement Integration time affects the measurement resolution for better resolution use a longer integration time and measurement speed for faster measurements use a shorter integration time Applies to all measurement functions except ac voltage ac current frequency and period The integration time for the math operations null min max dB dBm limit test is the same as the integration time for the measurement function in use Integration time is specified in number of power line cycles NPLCs The choices are 0 02 0 2
200. s 19 To Select a Range 20 To Set the Resolution 21 Front Panel Display Formats 22 To Rack Mount the Multimeter 23 Chapter 2 Front Panel Menu Operation Front Panel Menu Reference 27 A Front Panel Menu Tutorial 29 To Turn Off the Comma Separator 37 To Make Null Relative Measurements 38 To Store Minimum and Maximum Readings 39 To Make dB Measurements 40 To Make dBm Measurements 41 To Trigger the Multimeter 42 To Use Reading Hold 43 To Make dev dev Ratio Measurements 44 To Use Reading Memory 46 Chapter 3 Features and Functions Measurement Configuration AC Signal Filter 51 Continuity Threshold Resistance 52 DC Input Resistance 53 Resolution 54 Integration Time 57 Front Rear Input Terminal Switching 58 Autozero 59 Ranging 60 U9 U09 o ayant c Q xj c O O Contents Chapter 3 Features and Functions continued Math Operations Min Max Operation 64 Null Relative Operation 65 dB Measurements 67 dBm Measurements 68 Limit Testing 69 Triggering Trigger Source Choices 73 The Wait for Trigger State 76 Halting a Measurement in Progress 76 Number of Samples 77 Number of Triggers 78 Trigger Delay 79 Automatic Trigger Delays 81 Reading Hold 82 Voltmeter Complete Terminal 83 External Trigger Terminal 83 System Related Operations Reading Memory 84 Error Conditions 85 Self Test 86 Display Control 87 Beeper Control 88 Comma Separators 89 Firmware Revision Query 89 SCPI Lan
201. s Error 51 in 8840A 8842A G4 GET calibration status Returns 1000 G8 Return identification string Returns HEWLETT PACKARD 34401A 0 X X X P2 PUT variable calibration value Generates Error 51 in 8840A 8842A P3 PUT user defined message Generates Error 51 in 8840A 8842A ZO Perform self test Self test is not executed and no errors are recorded in the status byte Co Store input as calibration value Generates Error 51 in 8840A 8842A C1 Begin A D calibration Generates Error 51 in 8840A 8842A C2 Begin high frequency AC calibration Generates Error 51 in 8840A 8842A C3 Enter ERASE mode Generates Error 51 in 8840A 8842A 167 Chapter 4 Remote Interface Reference SCPI Compliance Information SCPI Compliance Information The following commands are device specific to the Agilent 34401A They are not included in the 1991 0 version of the SCPI standard However these commands are designed with the SCPI format in mind and they follow all of the syntax rules of the standard Many of the required SCPI commands are accepted by the multimeter but are not described in this manual for simplicity or clarity Most of these non documented commands duplicate the functionality of a command already described in this chapter CALCulate AVERage MINimum AVERage MAXimum AVERage AVERage AVERage COUNt DB REFerence lt value gt MINimum MAXimum DB REFerence MINimum MAXimum DBM REFerence lt
202. splay always turns on for menu operation this means that even when the display is turned off you can still operate the menu Remote Interface Operation DISPlay OFF ON disable enable the display DISPlay TEXT lt quoted string gt display the string enclosed in quotes DISPlay TEXT CLEar clear the displayed message The following command string shows how to display a message on the front panel DISP TEXT HELLO 87 Chapter 3 Features and Functions System Related Operations Beeper Control Normally the multimeter will emit a tone whenever certain conditions are met from the front panel For example the multimeter will beep when a stable reading is captured in reading hold You may want to disable the front panel beeper for certain applications e When you disable the beeper the multimeter will not emit a tone when 1 anew minimum or maximum is found in a min max test 2 a stable reading is captured in reading hold 3 a limit is exceeded in a limit test 4 a forward biased diode is measured in the diode test function e Disabling the beeper has no effect on the tone generated when 1 an error is generated 2 the continuity threshold is exceeded 3 you turn off the front panel menu Turning off the beeper does not disable the key click generated when you press a front panel key e The beeper state is stored in non volatile memory and does not change when power has been of
203. surement of the internal offset voltage The internal offset voltage error is subtracted from the input for improved accuracy This compensates for offset voltage changes due to temperature For maximum reading speed turn autozero off This will more than double your reading speeds for dc voltage resistance and dc current functions Autozero does not apply to other measurement functions 213 Chapter 7 Measurement Tutorial Making High Speed AC Measurements Making High Speed AC Measurements The multimeter s ac voltage and ac current functions implement three different low frequency filters These filters allow you to trade off low frequency accuracy for faster reading speed The fast filter settles in 0 1 seconds and is useful for frequencies above 200 Hz The medium filter settles in 1 second and is useful for measurements above 20 Hz The slow filter settles in 7 seconds and is useful for frequencies above 3 Hz With a few precautions you can perform ac measurements at speeds up to 50 readings per second Use manual ranging to eliminate autoranging delays By setting the preprogrammed settling trigger delays to 0 each filter will allow up to 50 readings per second However the measurement might not be very accurate since the filter is not fully settled In applications where sample to sample levels vary widely the medium filter will settle at 1 reading per second and the fast filter will settle at 10 readings per second
204. t MINimum MAXimum System Related Commands see page 132 for more information SYSTem ERRor FETCh SYSTem VERSion READ DATA POINts DISPlay OFF ON DISPlay FROR DISPlay IST TEXT lt quoted string gt y 5 gt TEXT TON TEXT CLEar L1 L2 SYSTem L3 BEEPer BEEPer STATe OFF ON BEEPer STATe Default parameters are shown in bold 109 Chapter 4 Remote Interface Reference Command Summary Status Reporting Commands see page 144 for more information SYSTem ERRor STATus QUEStionable ENABle lt enable value gt QUEStionable ENABle QUEStionable EVENt Questionable Date Event Register Enable Register o Voltage Overload Current Overload Not Used Not Used Not Used C L S Not Used Not Used Not Used ESE lt enable value gt wee ESE 9 Ohms Overtoad Not Used 14 Limit Test Fail LO ESR 12 Limit Test Fail HI Not Used Not Used xOPC 15 Not Used STATus PRESet STAT QUES ENAB OPC Standard Event Event Register Enable Register o oR co gt STAT QUES EVEN STAT QUES ENAB lt vatue gt bh Binary Weights Bed 2 286 222 2 512 a 2 1024 2 8 2 2048 gate 27 4096 2 32 2 8192 2 64 2 16384 2 128 2 32768 Status Byte Summary Register Enable Register Not Used Not Used Not Used Questionable Data OR Message Available Sta
205. t to the same common ground point This will reduce or eliminate any voltage difference between the devices Also make sure the multimeter and device under test are connected to the same electrical outlet whenever possible RL i HI i i i V l Ideal l test o RL Lo l i l i Ri gt 10 Ga Vground i l LJ E be eee fae DA aha cece J 77 Ri lead resistance Ri multimeter isolation resistance Vground voltage drop on ground bus 202 Chapter 7 Measurement Tutorial Resistance Measurements Resistance Measurements The Agilent 34401A offers two methods for measuring resistance 2 wire and 4 wire ohms For both methods the test current flows from the input HI terminal and then through the resistor being measured For 2 wire ohms the voltage drop across the resistor being measured is sensed internal to the multimeter Therefore test lead resistance is also measured For 4 wire ohms separate sense connections are required Since no current flows in the sense leads the resistance in these leads does not give a measurement error The errors mentioned earlier in this chapter for dc voltage measurements also apply to resistance measurements Additional error sources unique to resistance measurements are discussed on the following pages 4 Wire Ohms Measurements The 4 wire ohms method provides the most accurate way to measure small resistances Test lead resistanc
206. table sensitivity band adjustable only from the front panel to allow you to select which readings are considered stable enough to be displayed The band is expressed as a percent of reading on the selected range The multimeter will capture and display a new value only after three consecutive readings are within the band Select one of these values 0 01 0 10 default 1 00 or 10 00 of reading For example assume that the 1 00 band is selected and a 5 volt signal is applied to the multimeter If three consecutive readings are between 4 975 volts and 5 025 volts the display will show a new reading e The sensitivity band is stored in volatile memory the multimeter sets the band to 0 10 when power has been off or after an interface reset Ifthe multimeter is in autorange when you enable reading hold it will autorange to the correct range If the multimeter is in the manual range mode the same fixed range will be used for reading hold e When reading hold is enabled the input resistance is automatically set to 10 MQ AUTO OFF for all de voltage ranges This helps to minimize noise pickup when the test leads are open circuit e For certain applications it may be useful to use reading hold with reading memory See also Reading Memory on page 84 e Front Panel Operation After enabling reading hold you can select a different sensitivity band by pressing Shift gt Menu Recall 1 READ HOLD TRIG M
207. tage lt 2 V Reference HI to Input LO voltage lt 12V Measurement Noise Rejection 60 Hz 50Hz 5 DC CMRR Integration Time 100 PLC 1 67s 2s 10 PLC 167 ms 200 ms 1 PLC 16 7 ms 20 ms 0 2 PLC 3 ms 3 ms 0 02 PLC 400 us 400 us 140 dB Normal Mode Rejection 6 60 cB 7 60 cB 7 60 cB 7 0 dB 0 dB Operating Characteristics 8 Additional Function Digits Readings s Noise Error DCV DCI and 6 0 6 0 5 0 of range Resistance 61 6 5 0 of range 5 60 50 0 001 of range 5 300 0 001 of range 10 42 1000 0 01 of range 10 System Speeds 9 Function Change 26 sec Range Change 50 sec Autorange Time lt 30 ms ASCII readings to RS 232 55 sec ASCII readings to GPIB 1000 sec Max Internal Trigger Rate 1000 sec Max External Trigger Rate to Memory 1000 sec Max External Trigger Rate to GPIB 900 sec Autozero OFF Operation Following instrument warm up at calibration temperature 1 C and lt 10 minutes add 0 0002 range additional error 5 uV Settling Considerations Reading settling times are affected by source impedance cable dielectric characteristics and input signal changes 12 Accuracy specifications are for the voltage measured at the input terminals only 1 mA test current is typical Variation in the current source will create some variation in the voltage drop across a diode junction 217 Measurement Considerations Agilent recommends the use of PTFE or
208. ter from the selected remote interface The language is SCPI when the multimeter is shipped from the factory See also Programming Language Selection on page 94 1 Turn on the front panel menu A MEAS MENU 2 Move across to the I O MENU choice on this level E I O MENU 3 Move down a level and then across to the LANGUAGE command 5 LANGUAGE 4 Move down to the parameter level to select the language Choose from one of the following SCPI Agilent 3478A or Fluke 8840A SCPI 5 Save the change and turn off the menu The language selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset 165 Chapter 4 Remote Interface Reference Alternate Programming Language Compatibility Alternate Programming Language Compatibility You can configure the Agilent 34401A to accept and execute the commands of either the Agilent 3478A multimeter or the Fluke 8840A 8842A multimeter Remote operation will only allow you to access the functionality of the multimeter language selected You can take advantage of the full functionality of the 34401A only through the SCPI programming language For more information on selecting the alternate languages from the front panel menu see To Select the Programming Language on the previous page From the remote interface use the following commands to select the alternate languages Li select SCPI lan
209. ter 3 Features and Functions Triggering Number of Samples Normally the multimeter takes one reading or sample each time it receives a trigger from the selected trigger source if the multimeter is in the wait for trigger state You can however instruct the multimeter to take multiple readings for each trigger received e Number of samples 1 to 50 000 The default is 1 sample per trigger e The selected number of samples is stored in volatile memory the multimeter sets the sample count to 1 when power has been off or after a remote interface reset The CONFigure and MEASure commands automatically set the sample count to 1 e Front Panel Operation 3 N SAMPLES TRIG MENU e Remote Interface Operation SAMPle COUNt lt value gt MINimum MAXimum 77 Chapter 3 Features and Functions Triggering Number of Triggers Normally the multimeter will accept only one trigger before returning to the idle trigger state You can however instruct the multimeter to accept multiple triggers This feature is available only from the remote interface If you set the trigger count and then go to local front panel the multimeter ignores the trigger count setting when you return to remote the trigger count returns to the value you selected e Number of triggers 1 to 50 000 The default is 1 trigger e The selected number of triggers is stored in volatile memory the multimeter sets the trigger count to 1 when
210. terface the security code may contain up to 12 alphanumeric characters as shown below The first character must be a letter but the remaining characters can be letters or numbers You do not have to use all 12 characters but the first character must always be a letter A 12 characters e To secure the multimeter from the remote interface so that it can be unsecured from the front panel use the eight character format shown below The first two characters must be HP and the remaining characters must be numbers Only the last six characters are recognized from the front panel but all eight characters are required To unsecure the multimeter from the front panel omit the HP and enter the remaining numbers as shown on the following pages H P 8 characters If you forget your security code you can disable the security feature by adding a jumper inside the multimeter and then entering a new code See the Service Guide for more information 95 Calibration Security continued Chapter 3 Features and Functions Calibration Overview To Unsecure for Calibration You can unsecure the multimeter for calibration either from the front panel or remote interface The multimeter is secured when shipped from the factory and the security code is set to HP034401 e Front Panel Operation 1 SECURED CAL MENU If the multimeter is secured you will see the above command when you go into th
211. the respective bits in the summary register The status byte enable register request service is cleared when e You turn on the power and you have previously configured the multimeter using the PSC 1 command e You execute a SRE 0 command The status byte enable register will not be cleared at power on if you have previously configured the multimeter using PSC 0 136 Caution Chapter 4 Remote Interface Reference The SCPI Status Model Using Service Request SRQ and Serial POLL You must configure your bus controller to respond to the IEEE 488 service request SRQ interrupt to use this capability Use the status byte enable register SRE to select which summary bits will set the low level IEEE 488 SRQ signal When the status byte request service bit bit 6 is set an IEEE 488 SRQ interrupt message is automatically sent to the bus controller The bus controller may then poll the instruments on the bus to identify which one requested service the one with bit 6 set in its status byte The request service bit is only cleared by reading the status byte using an IEEE 488 serial poll or by reading the event register whose summary bit is causing the service request To read the status byte summary register send the IEEE 488 serial poll message Querying the summary register will return a decimal value which corresponds to the binary weighted sum of the bits set in the register Serial poll will automatically clear th
212. transmitted correctly The multimeter sets the DTR line FALSE in the following cases When the multimeter s input buffer is full when approximately 100 characters have been received it sets the DTR line FALSE pin 4 on the RS 232 connector When enough characters have been removed to make space in the input buffer the multimeter sets the DTR line TRUE unless the second case see below prevents this When the multimeter wants to talk over the interface which means that it has processed a query and has received a lt new line gt message terminator it will set the DTR line FALSE This implies that once a query has been sent to the multimeter the controller should read the response before attempting to send more data It also means that a lt new line gt must terminate the command string After the response has been output the multimeter sets the DTR line TRUE again unless the first case see above prevents this The multimeter monitors the DSR line to determine when the controller is ready to accept data over the interface The multimeter monitors the DSR line pin 6 on the RS 232 connector before each character is sent The output is suspended if the DSR line is FALSE When the DSR line goes TRUE transmission will resume 151 Chapter 4 Remote Interface Reference RS 232 Interface Configuration The multimeter holds the DTR line FALSE while output is suspended A form of interface deadlock exists until the contro
213. ts or 1 second 61 2 digits MIN 0 01 seconds MAX 1 second Stored in volatile memory PERiod APERture MINimum MAXimum Query the aperture time for period measurements 122 Chapter 4 Remote Interface Reference Measurement Configuration Commands SENSe DETector BANDwidth 3 20 200 MINimum MAXimum Specify the lowest frequency expected in the input signal The multimeter selects the slow medium default or fast ac filter based on the frequency you specify MIN 3 Hz MAX 200 Hz Stored in volatile memory SENSe DETector BANDwidth MINimum MAXimum Query the ac filter Returns 3 000000E 00 2 000000E 01 or 2 000000E 02 SENSe ZERO AUTO OFF ONCE ON Disable or enable default the autozero mode The OFF and ONCE parameters have a similar effect Autozero OFF does not issue a new zero measurement until the next time the multimeter goes to the wait for trigger state Autozero ONCE issues an immediate zero measurement Stored in volatile memory SENSe ZERO AUTO Query the autozero mode Returns 0 OFF or ONCE or 1 ON INPut IMPedance AUTO OFF ON Disable or enable the automatic input resistance mode for dc voltage measurements With AUTO OFF default the input resistance is fixed at 10 MQ for all ranges With AUTO ON the input resistance is set to gt 10 GQ for the 100 mV 1 V and 10 V ranges Stored in volatile memory INPut IMPedance AUTO
214. turned on when power has been off or after a remote interface reset Stored in volatile memory CALCulate NULL OFFSet lt value gt MINimum MAXimum Store a null value in the multimeter s Null Register You must turn on the math operation before writing to the math register You can set the null value to any number between 0 and 120 of the highest range for the present function MIN 120 of the highest range MAX 120 of the highest range Stored in volatile memory CALCulate NULL OFFSet MINimum MAXimum Query the null value CALCulate DB REFerence lt value gt MINimum MAXimum Store a relative value in the dB Relative Register You must turn on the math operation before writing to the math register You can set the relative value to any number between 0 dBm and 200 dBm MIN 200 00 dBm MAX 200 00 dBm Stored in volatile memory CALCulate DB REFerence MINimum MAXimum Query the dB relative value 125 Chapter 4 Remote Interface Reference Math Operation Commands CALCulate DBM REFerence lt valwe gt MINimum MAXimum Select the dBm reference value Choose from 50 75 93 110 124 125 135 150 250 300 500 600 800 900 1000 1200 or 8000 ohms MIN 50 Q MAX 8000 Q Stored in non volatile memory CALCulate DBM REFerence MINimum MAXimum Query the dBm reference resistance CALCulate LIMit LOWer lt value gt MINimum MAXimum Set the lower limit for limit testing You can set the v
215. unctions 21 Chapter 1 Quick Start Front Panel Display Formats Front Panel Display Formats Negative sign or blank positive 12 digit 0 or 1 Numeric digits Exponent m k M Measurement units VDC OHM HZ dB H DDD DDD EFFF mmoOz Front panel display format 5 digits Yo digit This is the 10 Vdc range 5 digits are displayed Yo digit 045 23 mVDC This is the 100 mVdc range 4 digits are displayed 113 325 6 OHM This is the 100 ohm range 6 digits are displayed OVL D mVDC This is an overload indication on the 100 mVdc range N 2 Chapter 1 Quick Start To Rack Mount the Multimeter To Rack Mount the Multimeter You can mount the multimeter in a standard 19 inch rack cabinet using one of three optional kits available Instructions and mounting hardware are included with each rack mounting kit Any Agilent System II instrument of the same size can be rack mounted beside the 34401A Remove the carrying handle and the front and rear rubber bumpers before rack mounting the multimeter f M EE N ae U Vee fli foo om o2999900 6e o000000 oe To remove the handle rotate it to the vertical position and pull the ends outward A 3 i E i J A Front Rear bottom view To remove the rubber bumper stretch a corner and then slide it of
216. ure the RS 232 interface using the parameters shown below Use the front panel I O MENU to select the baud rate parity and number of data bits see also pages 163 and 164 for more information e Baud Rate 300 600 1200 2400 4800 or 9600 baud factory setting e Parity and Data Bits None 8 data bits Even 7 data bits factory setting or Odd 7 data bits e Number of Start Bits 1 bit fixed e Number of Stop Bits 2 hits fixed Do not use the RS 232 interface if you have configured the multimeter to output pass fail signals on pins 1 and 9 Internal components on the RS 232 interface circuitry may be damaged 148 Chapter 4 Remote Interface Reference RS 232 Interface Configuration RS 232 Data Frame Format A character frame consists of all the transmitted bits that make up a single character The frame is defined as the characters from the start bit to the last stop bit inclusively Within the frame you can select the baud rate number of data bits and parity type The multimeter uses the following frame formats for seven and eight data bits Start 7 Data Parity Stop Stop Start 8 Data Stop Stop Connection to a Computer or Terminal To connect the multimeter to a computer or terminal you must have the proper interface cable Most computers and terminals are DTE Data Terminal Equipment devices Since the multimeter is also a DTE device you must use a DTE to DTE interface cable These cables are also
217. uted Any or all of these conditions can be reported in the standard event summary bit through the enable register You must write a decimal value using the ESE event status enable command to set the enable register mask An error condition standard event register bits 2 3 4 or 5 will always record one or more errors in the multimeter s error queue except for the following case Read the error queue using SYSTem ERRor A reading overload condition is always reported in both the standard event register bit 3 and the questionable data event register bits 0 1 or 9 However no error message is recorded in the multimeter s error queue Bit Definitions Standard Event Register Decimal Bit Value Definition 0 Operation Complete 1 All commands prior to and including an OPC command have been executed 1 Not Used 2 Always set to 0 2 Query Error 4 The multimeter tried to read the output buffer but it was empty Or a new command line was received before a previous query has been read Or both the input and output buffers are full 3 Device Error 8 A self test calibration or reading overload error occurred see error numbers 501 through 748 in chapter 5 4 Execution Error 16 An execution error occurred see error numbers 211 through 230 in chapter 5 5 Command Error 32 A command syntax error occurred see error numbers 101 through 158 in chapter 5 6 Not Used 64 Always set to 0 7 Po
218. value press Shift gt Menu Recall after enabling dBm operations This takes you to the dBm REF R command in the MATH MENU only if dBm is enabled Go down to the parameter level and then select a value 50 75 93 110 124 125 135 150 250 300 500 600 800 900 1000 1200 or 8000 ohms e The reference resistance is stored in non volatile memory and does not change when power has been off or after a remote interface reset 41 Chapter 2 Front Panel Menu Operation To Trigger the Multimeter To Trigger the Multimeter You can trigger the multimeter from the front panel using single trigger or auto trigger i 34401A HE Agilent 61 2 Digit Multimeter Auto Hald Auto Hold Single Single DK DK BR BK BR K le le le le le 7 id 7 id 7 7 Trig Enables single trigger x sample annunciator is on and triggers the multimeter during each measurement Toggles between auto trigger Trig annunciator is on when the and reading hold multimeter is waiting for single trigger auto trigger disabled e Auto triggering is enabled when you turn on the multimeter Notice that the sample annunciator turns on during each measurement e Single triggering takes one reading each time you press Single and then waits for the next trigger Continue pressing this key to trigger the multimeter Using an External Trigger The external trigger mode is also enabled
219. value gt MINimum MAXimum DBM REFerence MINimum MAXimum FUNCtion NULL DB DBM AVERage LIMit FUNCtion LIMit LOWer lt value gt MINimum MAXimum LIMit LOWer MINimum MAXimum LIMit UPPer lt value gt MINimum MAXimum LIMit UPPer MINimum MAXimum NULL OFFSet lt value gt MINimum MAXimum NULL OFFSet MINimum MAXimum CALibration COUNt SECure CODE lt new code gt SECure STATe OFF ON lt code gt SECure STATe STRing lt quoted string gt STRing CONFigure CONTinuity DIODe INPut IMPedance AUTO OFF ON IMPedance AUTO MEASure CONTinuity DIODe SAMP le COUNt lt value gt MINimum MAXimum COUNt MINimum MAXimum SENSe FUNCtion CONTinuity FUNCtion DIODe FREQuency VOLTage RANGe lt range gt MINimum MAXimum FREQuency VOLTage RANGe MINimum MAXimum FREQuency VOLTage RANGe AUTO OFF ON FREQuency VOLTage RANGe AUTO PERiod VOLTage RANGe lt range gt MINimum MAXimum PERiod VOLTage RANGe MINimum MAXimum PERiod VOLTage RANGe AUTO OFF ON PERiod VOLTage RANGe AUTO ZERO AUTO SYSTem LOCal REMote RWLock 168 Chapter 4 Remote Interface Reference IEEE 488 Compliance Information IEEE 488 Compliance Information Dedicated Hardware Lines Addressed Commands ATN Attention DCL Device Clear IFC Interface Clear EOI End or Identify Message Terminator REN Remote Enable GET Group Execute Trigger SRQ Service Request Interrupt
220. wer On 128 Power has been turned off and on since the last time the event register was read or cleared 140 Chapter 4 Remote Interface Reference The SCPI Status Model The standard event register is cleared when e You senda CLS clear status command e You query the event register using the ESR event status register command The standard event enable register is cleared when e You turn on the power and you have previously configured the multimeter using the PSC 1 command e You execute a ESE 0 command The standard event enable register will not be cleared at power on if you have previously configured the multimeter using PSC 0 141 Chapter 4 Remote Interface Reference The SCPI Status Model The Questionable Data Register The questionable data register provides information about the quality of the multimeter s measurement results Overload conditions and high low limit test results are reported Any or all of these conditions can be reported in the questionable data summary bit through the enable register You must write a decimal value using the STATus ENABle command to set the enable register mask QUI EStionable Note A reading overload condition is always reported in both the standard event register bit 3 and the questionable data event register bits 0 1 or 9 However no error message is recorded in the multimeter s error queue Bit D
221. when the multimeter is shipped from the factory The remote interface can be set only from the front panel e The interface selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset e Ifyou select the GPIB interface you must select a unique address for the multimeter The GPIB address is displayed when you turn on the multimeter e Ifyou select the RS 232 interface you must set the baud rate and parity for the multimeter RS 232 is displayed when you turn on the multimeter e Ifyou select the RS 232 interface and then set the GPIB address to the talk only address 31 the multimeter will send readings over the RS 232 interface when in the local mode e There are certain restrictions to be aware of when you are selecting the remote interface see also Programming Language Selection on page 94 The only programming language supported on RS 232 is SCPI GPIB 488 RS 232 SCPI Language X xX 3478A Language X Not allowed Fluke 8840A Language x Not allowed e Front Panel Operation 2 INTERFACE I O MENU See also To Select the Remote Interface on page 162 92 Chapter 3 Features and Functions Remote Interface Configuration Baud Rate Selection RS 232 You can select one of six baud rates for RS 232 operation The rate is set to 9600 baud when the multimeter is shipped from the factory The baud rate can be set onl
222. wing format the error string may contain up to 80 characters 113 Undefined header 85 Chapter 3 Features and Functions System Related Operations Self Test A power on self test occurs automatically when you turn on the multimeter This limited test assures you that the multimeter is operational This self test does not perform the extensive set of analog tests that are included as part of the complete self test described below A complete self test runs a series of tests and takes approximately 15 seconds to execute If all tests pass you can have a high confidence that the multimeter is operational 86 The results of the complete self test are stored in internal reading memory see page 84 Memory is cleared as the self test stores this information Other than clearing memory the complete self test does not alter the state of the multimeter If the complete self test is successful PASS is displayed on the front panel If the self test fails FAIL is displayed and the ERROR annunciator turns on See the Service Guide for instructions on returning the multimeter to Agilent for service Front Panel Operation You can perform some of the tests complete self test individually or you can perform all tests together at once 4 TEST SYS MENU Another way to perform the complete front panel self test is as follows Hold down Shift as you press the Power switch to turn on the multimeter hold down
223. y command and enter the result to assure synchronization e Enable your bus controller s IEEE 488 SRQ interrupt To Determine When a Command Sequence is Completed e Send a device clear message to clear the multimeter s output buffer e Clear the event registers with the CLS clear status command e Enable operation complete using the ESE 1 command standard event register e Send the OPC operation complete query command and enter the result to assure synchronization e Send your programming command string and place the OPC operation complete command as the last command e Usea serial poll to check to see when bit 5 standard event is set in the status byte summary register You could also configure the multimeter for an SRQ interrupt by sending SRE 32 status byte enable register bit 5 138 Chapter 4 Remote Interface Reference The SCPI Status Model How to Use the Message Available Bit MAV You can use the status byte message available bit bit 4 to determine when data becomes available to read into your bus controller The multimeter sets bit 4 when the first reading trigger occurs which can be TRIGger SOURce IMMediate The multimeter subsequently clears bit 4 only after all messages have been read from the output buffer The message available MAV bit can only indicate when the first reading is available following a READ command This can be helpful if you do not know wh
224. y from the front panel e Select one of the following 300 600 1200 2400 4800 or 9600 baud factory setting e The baud rate selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset e Front Panel Operation 3 BAUD RATE I O MENU See also To Set the Baud Rate on page 163 Parity Selection RS 232 You can select the parity for RS 232 operation The multimeter is configured for even parity with 7 data bits when shipped from the factory The parity can be set only from the front panel e Select one of the following None 8 data bits Even 7 data bits or Odd 7 data bits When you set the parity you are indirectly setting the number of data bits e The parity selection is stored in non volatile memory and does not change when power has been off or after a remote interface reset e Front Panel Operation 4 PARITY I O MENU See also To Set the Parity on page 164 93 Chapter 3 Features and Functions Remote Interface Configuration Programming Language Selection You can select one of three languages to program the multimeter from the selected remote interface The language is SCPI when the multimeter is shipped from the factory e Select one of the following SCPI Agilent 3478A or Fluke 8840A e The language selection is stored in non volatile memory and does not change when power has been off or after a remote inter
225. yed 51 2 N A 5 60 N A N A N A NPLC 0 2 Autozero On Digits Displayed 51 2 NPLC 0 2 Autozero Off Fast 5 digits 5 300 Digits Displayed 51 2 NPLC 0 02 Autozero On N A N A N A Digits Displayed 41 2 NPLC 0 02 Autozero Off Digits Displayed 41 Fast 4 digits 4 1000 1 See the Agilent 34401A specifications listed on page 217 60 Chapter 3 Features and Functions Measurement Configuration Ranging You can let the multimeter automatically select the range using autoranging or you can select a fixed range using manual ranging Autoranging is convenient because the multimeter automatically selects the appropriate range for each measurement However you can use manual ranging for faster measurements since the multimeter does not have to determine which range to use for each measurement e The selected mode auto or manual range is stored in volatile memory the multimeter returns to autoranging when power has been off or after a remote interface reset e Autorange thresholds Down range at lt 10 of range Up range at gt 120 of range e Ifthe input signal is greater than the present range can measure the multimeter gives an overload indication OVLD from the front panel or 9 90000000E 37 from the remote interface e For frequency and period measurements the multimeter uses one range for all inputs between 3 Hz and 300 kHz Th

Agilent 34401A 6.5 Digital Multimeter

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