Agilent 34401A - Manuals

34401A User’s Guide v 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 wit...

DECLARATION OF CONFORMITY According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014 Revision: B.01 Issue Date: 18 July 2001 Document 34401A.DOC Manufacturer’s Name: Agilent Technologies, Incorporated Manufacturer’s Address: 815 – 14 th St. SW Loveland, Colorado 80537USA Declares, that the product Produ...

The Front Panel at a Glance 1 Measurement Function keys 2 Math Operation keys 3 Single Trigger / Autotrigger / Reading Hold key 4 Shift / Local key 5 Front / Rear Input Terminal Switch 6 Range / Number of Digits Displayed keys 7 Menu Operation keys 2

The Front-Panel Menu at a Glance A: MEASurement MENU 1: AC FILTER > 2: CONTINUITY > 3: INPUT R > 4: RATIO FUNC > 5: RESOLUTION F: CALibration MENU * 1: SECURED > [ 1: UNSECURED ] > [ 2: CALIBRATE ] > 3: CAL COUNT > 4: MESSAGE * The commands enclosed in square brackets ( [ ] )...

Display Annunciators Adrs Rmt Man Trig Hold Mem Ratio Math ERRORRear Shift 4W Turns on during a measurement. Multimeter is addressed to listen or talk over the GPIB interface. Multimeter is in remote mode (remote interface). Multimeter is using manual ranging (autorange is disabled). Multimeter is w...

The Rear Panel at a Glance 1 Chassis Ground 2 Power-Line Fuse-Holder Assembly 3 Power-Line Voltage Setting 4 Front and Rear Current Input Fuse 5 Voltmeter Complete Output Terminal 6 External Trigger Input Terminal 7 GPIB (IEEE-488) Interface connector 8 RS-232 interface connector Use the front-panel...

In This Book Quick Start Chapter 1 prepares the multimeter for use and helps youget familiar with a few of its front-panel features. Front-Panel Menu Operation Chapter 2 introduces you to thefront-panel menu and describes some of the multimeter’s menu features. Features and Functions Chapter 3 gives...

Contents Chapter 1 Quick Start To Prepare the Multimeter for Use 13If the Multimeter Does Not Turn On 14To Adjust the Carrying Handle 16To Measure Voltage 17To Measure Resistance 17To Measure Current 18To Measure Frequency (or Period) 18To Test Continuity 19To Check Diodes 19To Select a Range 20To S...

Chapter 3 Features and Functions (continued) Math Operations Min-Max Operation 64 Null (Relative) Operation 65 dB Measurements 67 dBm Measurements 68 Limit Testing 69Triggering Trigger Source Choices 73 The Wait-for-Trigger State 76 Halting a Measurement in Progress 76 Number of Samples 77 Number of...

Quick Start One of the first things you will want to do with your multimeter is tobecome acquainted with its front panel. We have written the exercisesin this chapter to prepare the multimeter for use and help you getfamiliar with some of its front-panel operations. The front panel has two rows of k...

To Prepare the Multimeter for Use The following steps help you verify that the multimeter is ready for use. 1 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....

If the Multimeter Does Not Turn On Use the following steps to help solve problems you might encounterwhen turning on the multimeter. If you need more help, see theService Guide for instructions on returning the multimeter to Agilent forservice. 1 Verify that there is ac power to the multimeter. Firs...

See rear panel for proper fuse rating. Agilent Part Number: 2110-0817 (250 mAT) 100, 120, 220 (230) or 240 Vac 1 Remove the power cord. Remove the fuse-holder assembly from the rear panel. 2 Remove the line-voltage selector from the assembly. 3 Rotate the line-voltage selector until the correct volt...

To Adjust the Carrying Handle To adjust the position, grasp the handle by the sides and pull outward.Then, rotate the handle to the desired position. Bench-top viewing positions Carrying position Chapter 1 Quick Start To Adjust the Carrying Handle 16

To Measure Voltage Ranges: 100 mV, 1 V, 10 V, 100 V, 1000 V (750 Vac)Maximum resolution: 100 nV (on 100 mV range)AC technique: true RMS , ac-coupled To Measure Resistance Ranges: 100 Ω, 1 k Ω , 10 k Ω , 100 k Ω , 1 M Ω , 10 M Ω , 100 M Ω Maximum resolution: 100 µΩ (on 100 ohm range) 1 Chapter 1 Quic...

To Measure Current Ranges: 10 mA (dc only), 100 mA (dc only), 1 A , 3 AMaximum resolution: 10 nA (on 10 mA range)AC technique: true RMS , ac-coupled To Measure Frequency (or Period) Measurement band: 3 Hz to 300 kHz (0.33 sec to 3.3 µ sec) Input signal range: 100 mVac to 750 VacTechnique: reciprocal...

To Select a Range You can let the multimeter automatically select the range usingautoranging or you can select a fixed range using manual ranging. • Autoranging is selected at power-on and after a remote interface reset. • Autorange thresholds: Down range at <10% of range Up range at >120% of ...

To Set the Resolution You can set the display resolution to 4 1 ⁄ 2 , 5 1 ⁄ 2 , or 6 1 ⁄ 2 digits either to optimize measurement speed or noise rejection. In this book, the mostsignificant digit (leftmost on the display) is referred to as the “ 1 ⁄ 2 ” digit, since it can only be a “0” or “1.” • The...

Front-Panel Display Formats - H.DDD,DDD EFFF Front-panel display format. 10.216,5 VDC This is the 10 Vdc range, 5 1 ⁄ 2 digits are displayed. - 045.23 mVDC This is the 100 mVdc range, 4 1 ⁄ 2 digits are displayed. 113.325,6 OHM This is the 100 ohm range, 6 1 ⁄ 2 digits are displayed. OVL.D mVDC This...

To Rack Mount the Multimeter You can mount the multimeter in a standard 19-inch rack cabinet usingone of three optional kits available. Instructions and mounting hardwareare included with each rack-mounting kit. Any Agilent System II instrument of the same size can be rack-mounted beside the 34401A....

To rack mount a single instrument, order adapter kit 5063-9240. 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, a...

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 makefront-panel connections for the various types of measurements. If youare not familiar with this information, we recommend that you readchapt...

Front-Panel Menu Reference 1: AC FILTER 2: CONTINUITY 3: INPUT R 4: RATIO FUNC 5: RESOLUTION Selects the slow, medium, or fast ac filter. Sets the continuity beeper threshold (1 Ω to 1000 Ω ). Sets the input resistance for dc voltage measurements. Enables the dcv:dcv ratio function. Selects the meas...

A Front-Panel Menu Tutorial This section is a step-by-step tutorial which shows how to use thefront-panel menu. We recommend that you spend a few minutes with thistutorial to get comfortable with the structure and operation of the menu. The menu is organized in a top-down tree structure with three l...

MESSAGES DISPLAYED DURING 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 (Menu On/Off). To move across the choiceson a level, press or . To move down a level, press . MENUS You are on the “menu...

Menu Example 1 The following steps show you how to turn on the menu, move up ordown between levels, move across the choices on each level, and turn offthe menu. In this example, you will turn off the front-panel beeper. 1 Turn on the menu. You enter the menu on the “menus” level. The MEAS MENU is yo...

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.). 6: BEEP 5 Move down a level to the BEEP parameter choices. The first parameter choice is “ O...

Menu Example 2 The following exercise demonstrates how to use the menu recall featureas 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 BEE...

Menu Example 3 Some commands in the menu require that you enter a numericparameter value. The following steps show you how to enter a numberin 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 5 1 ⁄ 2 digits of resoluti...

5 Move down to edit the NULL VALUE parameter. The null value should be 0.0 Vdc when you come to this point in themenu for the first time. For this example, you will set the null value to –2.0 volts. ∧ 000.000 mVDC When you see the flashing “ ∧ ” on the left side of the display, you can abort the edi...

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 10 Increase the displayed number by a factor of 10. Notice that the position of the decimal point changes and the displayednumber increases by a factor of 10. -...

To Turn Off the Comma Separator The multimeter can display readings on the front panel with or withouta comma separator. The following steps show how to disable the comma. 08.241,53 VDC 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 dow...

To Make Null (Relative) Measurements Each null measurement, also called relative, is the difference between astored null value and the input signal. Result = reading – null value • You can make null measurements with any function exceptcontinuity, diode, or ratio. The null operation is local to the ...

To Store Minimum and Maximum Readings You can store the minimum and maximum readings during a seriesof measurements. The following discussion shows how to read theminimum, maximum, average, and reading count. • You can use min-max with any function except continuity or diode test.The min-max operati...

To Make dB Measurements Each dB measurement is the difference between the input signal and astored relative value, with both values converted to dBm. dB = reading in dBm – relative value in dBm • Select DC V or AC V . • The first reading taken after you enable dB measurements isconverted to dBm and ...

To Make dBm Measurements The dBm operation calculates the power delivered to a resistancereferenced to 1 milliwatt. dBm = 10 × Log 10 ( reading 2 / reference resistance / 1 mW ) • Select DC V or AC V . • The factory setting for the reference resistance is 600 Ω . To select a different value, press S...

To Trigger the Multimeter You can trigger the multimeter from the front panel using single triggeror auto trigger. • Auto triggering is enabled when you turn on the multimeter. Noticethat the ∗ (sample) annunciator turns on during each measurement. • Single triggering takes one reading each time you...

To Use Reading Hold The reading hold feature allows you to capture and hold a stablereading on the display. When a stable reading is detected, themultimeter emits a beep and holds the value on the display. • Reading hold has an adjustable sensitivity band to allow you to select which readings are co...

To Make dcv:dcv Ratio Measurements To calculate a ratio, the multimeter measures a dc reference voltageapplied to the Sense terminals and the voltage applied to the Input terminals. • At the Sense terminals, the reference voltage measurement function is always dc voltage and has a maximum measurable...

The following steps show you how to select the ratio function using thefront-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:D...

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. 1 Select the function. Select any measurement function. You can also select Null, Min–Max,dB, dBm, or limit test. You can change the function ...

6 Move down a level and then across to the “ ON ” choice. ON 7 Save the change and exit the menu. Notice that the Mem (memory) annunciator turns on to indicate that the multimeter is ready to store readings. Up to 512 readings can be storedin first-in-first-out ( FIFO ) order. When memory is full, t...

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). If no readings are stored in memory, “ EMPTY ” is displayed. The stored readings...

Features and Functions You will find that this chapter makes it easy to look up all the detailsabout a particular feature of the multimeter. Whether you are operatingthe multimeter from the front panel or from the remote interface, thischapter will be useful. This chapter is divided into the followi...

Measurement Configuration This section contains information to help you configure the multimeterfor making measurements. You may never have to change any of themeasurement parameters discussed here, but they are provided to giveyou the flexibility you might need. AC Signal Filter The multimeter uses...

Continuity Threshold Resistance When measuring continuity, the multimeter emits a continuous tone ifthe measured resistance is less than the threshold resistance. You canset the threshold to any value between 1 Ω and 1000 Ω . The threshold resistance is adjustable only from the front panel. • The th...

DC Input Resistance Normally, the multimeter’s input resistance is fixed at 10 M Ω for all dc voltage ranges to minimize noise pickup. To reduce the effects ofmeasurement loading errors, you can set the input resistance to greaterthan 10 G Ω for the 100 mVdc, 1 Vdc, and 10 Vdc ranges. Applies to dc ...

Resolution Resolution is expressed in terms of number of digits the multimeter canmeasure or display. You can set the resolution to 4, 5, or 6 full digits,plus a “ 1 ⁄ 2 ” digit which can only be a “0” or “1”. To increase measurement accuracy and improve noise rejection, select 6 1 ⁄ 2 digits. To in...

10.216,5 VDC This is the 10 Vdc range, 5 1 ⁄ 2 digits are displayed. - 045.23 mVDC This is the 100 mVdc range, 4 1 ⁄ 2 digits are displayed. 113.325,6 OHM This is the 100 ohm range, 6 1 ⁄ 2 digits are displayed. • The resolution is stored in volatile memory; the multimeter sets theresolution to 5 1 ...

Resolution (continued) • Front-Panel Operation: Select either the slow or fast mode for eachresolution setting. The default mode is 5 digits slow. 5: RESOLUTION (MEAS MENU) See also “To Set the Resolution,” on page 21. • Remote Interface Operation: You can set the resolution using thefollowing comma...

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 fastermeasu...

Integration Time (continued) • Front-Panel Operation: Integration time is set indirectly when youselect the number of digits. See the table for resolution on page 54. • Remote Interface Operation: < function >:NPLCycles {0.02|0.2|1|10|100|MINimum|MAXimum} For frequency and period measurements,...

Autozero When autozero is enabled (default), the multimeter internallydisconnects the input signal following each measurement, and takes azero reading. It then subtracts the zero reading from the precedingreading. This prevents offset voltages present on the multimeter’s inputcircuitry from affectin...

Ranging You can let the multimeter automatically select the range usingautoranging or you can select a fixed range using manual ranging.Autoranging is convenient because the multimeter automatically selectsthe appropriate range for each measurement. However, you can usemanual ranging for faster meas...

Ranging (continued) • Front-Panel Operation: Use the front-panel RANGE keys to select autoranging or manual ranging. For frequency and periodmeasurements from the front panel, ranging applies to the signal’sinput voltage, not its frequency. See also “To Select a Range,” on page 20. • Remote Interfac...

Math Operations There are five math operations available, only one of which can beenabled at a time. Each math operation performs a mathematicaloperation 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 o...

Min–Max Operation The min-max operation stores the minimum and maximum readingsduring a series of measurements. The multimeter then calculates theaverage of all readings and records the number of readings taken sincemin-max was enabled. Applies to all measurement functions, except continuity and dio...

Null (Relative) (continued) • The null value is stored in the multimeter’s Null Register. There aretwo ways you can specify the null value. First, you can enter aspecific number into the register from the front-panel menu or fromthe remote interface. Any previously stored value is replaced with then...

dB Measurements Each dB measurement is the difference between the input signal and astored 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. • The relative value is adjustable and you can set it to a...

• Remote Interface Operation: You can use the following commands tomake dB measurements. Math must be enabled before you can store avalue to the Relative Register. CALCulate:FUNCtion DB CALCulate:STATe {OFF|ON} CALCulate:DB:REFerence {< value >|MINimum|MAXimum} dBm Measurements The dBm operati...

Limit Testing The limit test operation enables you to perform pass/fail testing toupper and lower limits that you specify. Applies to all measurement functions, except continuity and diode tests. • You can set the upper and lower limits to any value between 0 and ± 120% of the highest range, for the...

Limit Testing (continued) • Remote Interface Operation: You can use the following commands forlimit testing. CALCulate:FUNCtion LIMit CALCulate:STATe {OFF|ON} CALCulate:LIMit:LOWer {< value >|MINimum|MAXimum} CALCulate:LIMit:UPPer {< value >|MINimum|MAXimum} • There are two unused pins o...

Triggering The multimeter’s triggering system allows you to generate triggerseither manually or automatically, take multiple readings per trigger,and insert a delay before each reading. Normally, the multimeter willtake one reading each time it receives a trigger, but you can specifymultiple reading...

Agilent 34401A Triggering System Delay Idle State Wait-for- Trigger State Measurement Sample Sample Count ≠ 1 Trigger Count ≠ 1 Initiate Triggering MEASure? READ? INITiate Trigger Source TRIGger:SOURce IMMediate TRIGger:SOURce EXTernal TRIGger:SOURce BUS Front-panel “Single” key Trigger Delay TRIGge...

Trigger Source Choices You must specify the source from which the multimeter will accept atrigger. From the front panel, the multimeter will accept a singletrigger, a hardware trigger from the Ext Trig terminal, or continuouslytake readings using auto trigger. At power-on, auto triggering is used.Fr...

External Triggering In the external trigger mode, the multimeterwill 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 ...

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 triggerwill not be accepted until the multimeter is in this state. If a triggersignal is present, and if multimeter is in the “wait-for-tri...

Number of Samples Normally, the multimeter takes one reading (or sample) each time itreceives a trigger from the selected trigger source (if the multimeter isin the wait-for-trigger state). You can, however, instruct the multimeterto take multiple readings for each trigger received. • Number of samp...

Number of Triggers Normally, the multimeter will accept only one trigger before returningto the “idle” trigger state. You can, however, instruct the multimeter toaccept multiple triggers. This feature is available only from the remote interface. If you set thetrigger count and then go to local (fron...

Trigger Delay You can insert a delay between the trigger signal and each sample thatfollows. This may be useful in applications where you want to allow theinput to settle before taking a reading, or for pacing a burst of readings.If you do not specify a trigger delay, the multimeter automaticallysel...

• Front-Panel Operation (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 ∨ until ZERO DELAY is reached, then press Menu Enter. To select the automatic trigger de...

Automatic Trigger Delays If you do not specify a trigger delay, the multimeter selects anautomatic delay for you. The delay is determined by function, range,integration time, and ac filter setting. • DC Voltage and DC Current (for all ranges): • Resistance (2-wire and 4-wire): • AC Voltage and AC Cu...

Reading Hold The reading hold feature allows you to capture and hold a stablereading on the front-panel display. This is especially useful in situationswhere you want to take a reading, remove the test probes, and have thereading remain on the display. When a stable reading is detected, themultimete...

Voltmeter Complete Terminal The rear-panel VM Comp (voltmeter complete) terminal provides alow-true pulse after the completion of each measurement. Voltmetercomplete and external trigger (see below) implement a standard hardwarehandshake sequence between measurement and switching devices. External T...

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 directlyrelated to making measurements but is an important part of operatingthe multimeter. Reading Memory The multimeter can store up...

Error Conditions When the front-panel ERROR annunciator turns on, one or more command syntax or hardware errors have been detected. A record of upto 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 fi...

Self-Test A power-on self-test occurs automatically when you turn on themultimeter. This limited test assures you that the multimeter isoperational. This self-test does not perform the extensive set of analogtests that are included as part of the complete self-test described below. A complete self-t...

Display Control To speed up your measurement rate, or for security reasons, you maywant to turn off the front-panel display. From the remote interface, youcan also display a 12-character message on the front panel. • When the display is turned off, readings are not sent to the displayand all display...

Beeper Control Normally, the multimeter will emit a tone whenever certain conditionsare met from the front panel. For example, the multimeter will beepwhen a stable reading is captured in reading hold. You may want todisable the front-panel beeper for certain applications. • When you disable the bee...

Comma Separators The multimeter can display readings on the front panel with or withouta comma separator. This feature is available only from the front panel. 08.241,53 VDC • The display format is stored in non-volatile memory, and does notchange when power has been off or after a remote interface r...

SCPI Language Version Query The multimeter complies with the rules and regulations of the presentversion 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 ...

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 mult...

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 when the multimeter is shipped from the factory. The remote interface can be set only from the front-pane...

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 only from the front-panel. • Select one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud(factory ...

Programming Language Selection You can select one of three languages to program the multimeter fromthe selected remote interface. The language is SCPI when the multimeter is shipped from the factory. • Select one of the following: SCPI, Agilent 3478A, or Fluke 8840A. • The language selection is stor...

Calibration Overview This section gives a brief introduction to the calibration features of themultimeter. 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 orun...

CalibrationSecurity (continued) To Unsecure for Calibration You can unsecure the multimeterfor calibration either from the front panel or remote interface.The multimeter is secured when shipped from the factory, and thesecurity code is set to “ HP034401 ”. • Front-Panel Operation: 1: SECURED (CAL ME...

To Secure Against Calibration You can secure the multimeteragainst calibration either from the front panel or remote interface.The multimeter is secured when shipped from the factory, and thesecurity code is set to “ HP034401 ”. Make sure you have read the security code rules on page 95 beforeattemp...

CalibrationSecurity (continued) To Change the Security Code To change the security code, you mustfirst unsecure the multimeter, and then enter a new code. Make sureyou have read the security code rules on page 95 before attempting tosecure the multimeter. • Front-Panel Operation: To change the secur...

Calibration Message You can use the calibration message feature to record calibrationinformation about your multimeter. For example, you can store suchinformation as the last calibration date, the next calibration due date,the multimeter’s serial number, or even the name and phone number ofthe perso...

Operator Maintenance This section describes how to replace the power-line and current fuses.If you need additional information about replacing parts or repairingthe multimeter, see the Service Guide. To Replace the Power-Line Fuse The power-line fuse is located within the multimeter’s fuse-holderass...

Power-On and Reset State Measurement Configuration AC Filter Autozero • Continuity Threshold Function Input Resistance Integration Time Range Resolution Math Operations Math State, Function Math Registers • dBm Reference Resistance Triggering Operations Reading Hold Threshold Samples Per Trigger Tri...

Remote Interface Reference • Command Summary, starting on page 105 • Simplified Programming Overview, starting on page 112 • The MEASure? and CONFigure Commands, starting on page 117 • Measurement Configuration Commands, starting on page 121 • Math Operation Commands, starting on page 124 • Triggeri...

Command Summary This section summarizes the SCPI (Standard Commands for Programmable Instruments) commands available to program themultimeter. Refer to the later sections in this chapter for more completedetails on each command. Throughout this manual, the following conventions are used for SCPI com...

Default parameters are shown in bold . Measurement Configuration Commands (see page 121 for more information) [SENSe:] FUNCtion "VOLTage:DC" FUNCtion "VOLTage:DC:RATio" FUNCtion "VOLTage:AC" FUNCtion "CURRent:DC" FUNCtion "CURRent:AC" FUNCtion "RESistance&...

Measurement Configuration Commands (continued) [SENSe:] VOLTage:DC:RESolution {< resolution >|MINimum|MAXimum} VOLTage:DC:RESolution? [MINimum|MAXimum] VOLTage:AC:RESolution {< resolution >|MINimum|MAXimum} VOLTage:AC:RESolution? [MINimum|MAXimum] CURRent:DC:RESolution {< resolution &...

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 {< value >|MINimum|MAXimum} :NULL:OFFSet? [MINim...

Triggering Commands (see page 127 for more information) INITiate READ? TRIGger :SOURce {BUS|IMMediate |EXTernal} :SOURce? TRIGger :DELay {< seconds >|MINimum|MAXimum} :DELay? [MINimum|MAXimum] TRIGger :DELay:AUTO {OFF|ON} :DELay:AUTO? SAMPle :COUNt {< value >|MINimum|MAXimum} :COUNt? [MI...

Default parameters are shown in bold . Status Reporting Commands (see page 144 for more information) SYSTem:ERRor? STATus :QUEStionable:ENABle < enable value > :QUEStionable:ENABle? :QUEStionable:EVENt? STATus:PRESet *CLS *ESE < enable value > *ESE? *ESR? *OPC *OPC? *PSC {0|1} *PSC? *SRE...

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 < enable value > *ESE? *ESR? *IDN? *OPC *OPC? *PSC {0|1} *PSC? *RST *SRE < enable value > *SRE? *STB? *TRG *TST?...

Simplified Programming Overview You can program the multimeter to take measurements from the remoteinterface using the following simple seven-step sequence. 1. Place the multimeter in a known state (often the reset state). 2. Change the multimeter’s settings to achieve the desired configuration. 3. ...

Using the MEASure? Command The easiest way to program the multimeter for measurements is byusing the MEASure? command. However, this command does not offer much flexibility. When you execute the command, the multimeterpresets the best settings for the requested configuration andimmediately performs ...

Using the range and resolution Parameters With the MEASure? and CONFigure commands, you can select the measurement function, range, and resolution all in one command.Use the range parameter to specify the expected value of the inputsignal. The multimeter then selects the correct measurement range. F...

C a u t i o n If you send two query commands without reading the response from thefirst, and then attempt to read the second response, you may receive somedata from the first response followed by the complete second response.To avoid this, do not send a query command without reading theresponse. Whe...

The MEASure? and CONFigure Commands See also “Measurement Configuration,” starting on page 51 in chapter 3. • For the range parameter, MIN selects the lowest range for the selected function; MAX selects the highest range; DEF selects autoranging. • For the resolution parameter, specify the resolutio...

CONFigure:FREQuency {< range >|MIN|MAX|DEF},{< resolution >|MIN|MAX|DEF} Preset and configure a frequency measurement with the specified rangeand resolution. This command does not initiate the measurement.For frequency measurements, the multimeter uses one “range” for allinputs between 3...

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 beenabled at a time. Each math operation performs a mathematicaloperation on each reading or stores data on a series of readings.The selected math ope...

CALCulate:AVERage:MINimum? Read the minimum value found during a min-max operation. Themultimeter clears the value when min-max is turned on, when powerhas been off, or after a remote interface reset. [Stored in volatile memory] CALCulate:AVERage:MAXimum? Read the maximum value found during a min-ma...

Triggering See also “Triggering,” starting on page 71 in chapter 3. The multimeter’s triggering system allows you to generate triggerseither manually or automatically, take multiple readings per trigger,and insert a delay before each reading. Normally, the multimeter willtake one reading each time i...

Triggering Commands See also “Triggering,” starting on page 71 in chapter 3. INITiate Change the state of the triggering system from the “idle” state to the“wait-for-trigger” state. Measurements will begin when the specifiedtrigger conditions are satisfied after the INITiate command is received. The...

TRIGger:DELay {< seconds >|MINimum|MAXimum} Insert a trigger delay between the trigger signal and each samplethat follows. If you do not specify a trigger delay, the multimeterautomatically selects a delay for you. Select from 0 to 3600 seconds. MIN = 0 seconds. MAX = 3600 seconds. [Stored in ...

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 th...

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) a new minimum or maximum is found in a min–max test. 2) a stable reading is c...

The SCPI Status Model All SCPI instruments implement status registers in the same way. The status system records various instrument conditions in threeregister groups: the Status Byte register, the Standard Event register,and the Questionable Data register. The status byte register recordshigh-level...

SCPI Status System 4 Chapter 4 Remote Interface Reference The SCPI Status Model 135

The Status Byte The status byte summary register reports conditions from other statusregisters. Query data that is waiting in the multimeter’s output buffer isimmediately reported through the “message available” bit (bit 4). Bits inthe summary registers are not latched. Clearing an event register wi...

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 stat...

How to Use the Message Available Bit ( MAV ) You can use the status byte “message available” bit (bit 4) to determinewhen data becomes available to read into your bus controller. Themultimeter sets bit 4 when the first reading trigger occurs (which can be TRIGger:SOURce:IMMediate ). The multimeter s...

The Standard Event Register The standard event register reports the following types of instrumentevents: power-on detected, command syntax errors, command executionerrors, self-test or calibration errors, query errors, or when an *OPC command is executed. Any or all of these conditions can be report...

The Questionable Data Register The questionable data register provides information about the qualityof the multimeter’s measurement results. Overload conditions andhigh/low limit test results are reported. Any or all of these conditionscan be reported in the questionable data summary bit through the...

Status Reporting Commands SYSTem:ERRor? Query the multimeter’s error queue. Up to 20 errors can be stored in thequeue. Errors are retrieved in first-in-first out ( FIFO ) order. Each error string may contain up to 80 characters. STATus:QUEStionable:ENABle < enable value > Enable bits in the Qu...

*ESR? Query the Standard event register. The multimeter returns a decimalvalue which corresponds to the binary-weighted sum of all bits set in theregister. *OPC Sets the “operation complete” bit (bit 0) in the Standard Event registerafter the command is executed. *OPC? Returns “1” to the output buff...

Calibration Commands See “Calibration Overview” starting on page 95 for an overview of thecalibration features of the multimeter. For a more detailed discussionof the calibration procedures, see chapter 4 in the Service Guide. CALibration? Perform a calibration using the specified calibration value(...

CALibration:STRing < quoted string > Record calibration information about your multimeter. For example,you can store such information as the last calibration date, the nextcalibration due date, the instrument serial number, or even the nameand phone number of the person to contact for a new ca...

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 communic...

RS-232 Data Frame Format A character frame consists of all the transmitted bits that make up asingle character. The frame is defined as the characters from the start bitto the last stop bit, inclusively. Within the frame, you can select thebaud rate, number of data bits, and parity type. The multime...

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 befor...

The multimeter holds the DTR line FALSE while output is suspended. A form of interface deadlock exists until the controller asserts the DSR line TRUE to allow the multimeter to complete the transmission. You can break the interface deadlock by sending the <Ctrl-C> character,which clears the op...

An Introduction to the SCPI Language SCPI (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 t...

Command Format Used in This Manual The format used to show commands in this manual is shown below: VOLTage:DC:RANGe {< range >|MINimum|MAXimum} The command syntax shows most commands (and some parameters)as a mixture of upper- and lower-case letters. The upper-case lettersindicate the abbrevia...

Command Separators A colon ( : ) is used to separate a command keyword from a lower-levelkeyword. You must insert a blank space to separate a parameter from acommand keyword. If a command requires more than one parameter,you must separate adjacent parameters using a comma as shown below: "CONF:V...

Querying Parameter Settings You can query the current value of most parameters by adding aquestion mark ( ? ) to the command. For example, the followingcommand sets the sample count to 10 readings: "SAMP:COUN 10" You can query the sample count by executing: "SAMP:COUN?" You can also ...

IEEE-488.2 Common Commands The IEEE -488.2 standard defines a set of common commands that perform functions like reset, self-test, and status operations. Commoncommands always begin with an asterisk ( * ), are four to five characters in length, and may include one or more parameters. The commandkeyw...

Boolean Parameters Boolean parameters represent a single binarycondition that is either true or false. For a false condition, the multimeterwill accept “ OFF ” or “0”. For a true condition, the multimeter will accept “ ON ” or “1”. When you query a boolean setting, the instrument will always return ...

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 programming languages and IEEE-488 interface cards provide access to this capability through their own unique commands. The status registers, the er...

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 between0 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 tur...

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...

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:...

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 thefactory. 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...

To Select the Programming Language You can select one of three languages to program the multimeterfrom the selected remote interface. The language is SCPI when the multimeter is shipped from the factory. See also “ProgrammingLanguage Selection,” on page 94. 1 Turn on the front-panel menu. A: MEAS ME...

Alternate Programming Language Compatibility You can configure the Agilent 34401A to accept and execute thecommands of either the Agilent 3478A multimeter or the Fluke8840A/8842A multimeter. Remote operation will only allow you toaccess the functionality of the multimeter language selected. You cant...

SCPI Compliance Information The following commands are device-specific to the Agilent 34401A. Theyare 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 requir...

IEEE-488 Compliance Information IEEE-488.2 Common Commands *CLS *ESE < enable value > *ESE?*ESR?*IDN?*OPC*OPC?*PSC {0|1} *PSC? *RST*SRE < enable value > *SRE?*STB?*TRG*TST? Dedicated Hardware Lines Addressed Commands ATN IFC RENSRQ Attention Interface Clear Remote Enable Service Request ...

Error Messages • Errors are retrieved in first-in-first-out ( FIFO ) order. The first error returned is the first error that was stored. When you haveread 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 h...

Execution Errors -101 Invalid character An invalid character was found in the command string. You may haveinserted a character such as #, $, or % in the command header or withina parameter. Example: CONF:VOLT#DC -102 Syntax error Invalid syntax was found in the command string. You may haveinserted a...

-112 Program mnemonic too long A command header was received which contained more than themaximum 12 characters allowed. Example: CONFIGURATION:VOLT:DC -113 Undefined header A command was received that is not valid for this multimeter. You mayhave misspelled the command or it may not be a valid comm...

-151 Invalid string data An invalid character string was received. Check to see if you haveenclosed the character string in single or double quotes and that thestring contains valid ASCII characters. Example: DISP:TEXT ’ON (the ending quote is missing). -158 String data not allowedA character string...

-221 Settings conflict This error can be generated in one of the following situations: • You sent a CONFigure or MEASure command with autorange enabled and with a fixed resolution. Example: CONF:VOLT:DC DEF,0.1 • You turned math on ( CALC:STAT ON ) and then changed to a math operation that was not v...

-350 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. -410 Query INTERRUPTED A comman...

616 DC current sense failed 617 Ohms 100 uA source failed 618 DC high voltage attenuator failed 619 Ohms 1 mA source failed 620 AC rms zero failed 621 AC rms full scale failed 622 Frequency counter failed 623 Cannot calibrate precharge 624 Unable to sense line frequency 625 I/O processor does not re...

Application Programs This chapter contains several remote interface application programsto help you develop programs for your measurement application.Chapter 4, “Remote Interface Reference,” starting on page 103, lists thesyntax for the SCPI (Standard Commands for Programmable Instruments) commands ...

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 themultimeter for measurements. However, MEASure? does not offer much flexibility. The example is shown in BASIC and QuickBASIC. 10 REAL...

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 isshown in BA...

Using the Status Registers The following example shows how you can use the multimeter’s statusregisters to determine when a command sequence is completed. Formore information, see “The SCPI Status Model,” starting on page 134.The example is shown in BASIC and QuickBASIC (see page 190). 10 REAL Aver,...

RS-232 Operation Using QuickBASIC The following example shows how to send command instructions andreceive command responses over the RS-232 interface 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 Car...

RS-232 Operation Using Turbo C The following example shows how to program an AT personal computerfor interrupt-driven COM port communications. SCPI commands can be sent to the Agilent 34401A and responses received for commands thatquery information. The following program is written in Turbo C and ca...

Measurement Tutorial The Agilent 34401A is capable of making highly accuratemeasurements. In order to achieve the greatest accuracy, you must takethe necessary steps to eliminate potential measurement errors. Thischapter describes common errors found in measurements and givessuggestions to help you ...

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. To reduce the effects of loading errors, and to minimize noise pickup,you ...

Rejecting Power-Line Noise Voltages A desirable characteristic of integrating analog-to-digital (A/D) convertersis their ability to reject spurious signals. Integrating techniques rejectpower-line related noise present with dc signals on the input. This iscalled normal mode rejection or NMR . Normal...

Common Mode Rejection (CMR) Ideally, a multimeter is completely isolated from earth-referenced circuits.However, there is finite resistance between the multimeter’s input LOterminal and earth ground as shown below. This can cause errors whenmeasuring low voltages which are floating relative to earth...

Noise Caused by Ground Loops When measuring voltages in circuits where the multimeter and thedevice-under-test are both referenced to a common earth ground,a “ground loop” is formed. As shown below, any voltage differencebetween the two ground reference points (V ground ) causes a current to flow th...

Resistance Measurements The Agilent 34401A offers two methods for measuring resistance:2-wire and 4-wire ohms. For both methods, the test current flows fromthe input HI terminal and then through the resistor being measured. For2-wire ohms, the voltage drop across the resistor being measured issensed...

Removing Test Lead Resistance Errors To eliminate offset errors associated with the test lead resistance in2-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 multime...

Errors in High Resistance Measurements When you are measuring large resistances, significant errors can occurdue to insulation resistance and surface cleanliness. You should takethe necessary precautions to maintain a “clean” high-resistance system.Test leads and fixtures are susceptible to leakage ...

True RMS AC Measurements True RMS responding multimeters, like the Agilent 34401A, measure the “heating” potential of an applied voltage. Unlike an “averageresponding” measurement, a true RMS measurement is used to determine the power dissipated in a resistor. The power is proportionalto the square ...

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 ripplepresent on dc power supplies. There are situations, however, where youmight want to know the ac+dc ...

Crest Factor (continued) You can estimate the measurement error due to signal crest factor asshown 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 chapt...

Loading Errors (ac volts) In the ac voltage function, the input of the Agilent 34401A appears as a1 M Ω resistance in parallel with 100 pF of capacitance. The cabling that you use to connect signals to the multimeter will also add additionalcapacitance and loading. The table below shows the multimet...

Measurements Below Full Scale You can make the most accurate ac measurements when the multimeteris at full scale of the selected range. Autoranging occurs at 10% and120% of full scale. This enables you to measure some inputs at full scaleon one range and 10% of full scale on the next higher range. T...

Low-Level Measurement Errors When measuring ac voltages less than 100 mV, be aware that thesemeasurements are especially susceptible to errors introduced byextraneous noise sources. An exposed test lead will act as an antennaand a properly functioning multimeter will measure the signalsreceived. The...

Frequency and Period Measurement Errors The multimeter uses a reciprocal counting technique to measurefrequency and period. This method generates constant measurementresolution for any input frequency. The multimeter’s ac voltagemeasurement section performs input signal conditioning. All frequencyco...

Making High-Speed AC Measurements The multimeter’s ac voltage and ac current functions implement threedifferent low-frequency filters. These filters allow you to trade-off lowfrequency accuracy for faster reading speed. The fast filter settles in0.1 seconds, and is useful for frequencies above 200 H...

DC Characteristics DC Characteristics Accuracy Specifications ± ( % of reading + % of range ) [ 1 ] Function Range [ 3 ] Test Current or Burden Voltage 90 Day 23°C ± 5°C 1 Year 23°C ± 5°C Temperature Coefficient /°C 0°C – 18°C 28°C – 55°C DC Voltage 100.0000 mV1.000000 V 10.00000 V 100.0000 V 1000.0...

DC Characteristics Function DCV, DCI, andResistance Digits 6 1 ⁄ 2 6 1 ⁄ 2 5 1 ⁄ 2 5 1 ⁄ 2 4 1 ⁄ 2 Readings/s 0.6 (0.5) 6 (5) 60 (50) 300 1000 Additional Noise Error 0% of range0% of range0.001% of range 0.001% of range0.01% of range System Speeds [ 9 ] Function ChangeRange ChangeAutorange Time ASCI...

AC Characteristics AC Characteristics Accuracy Specifications ± ( % of reading + % of range ) [ 1 ] Function Range [ 3 ] Frequency 24 Hour [ 2 ]23°C ± 1°C 1 Year 23°C ± 5°C Temperature Coefficient/°C 0°C – 18°C28°C – 55°C True RMS AC Voltage[ 4 ] 100.0000 mV 1.000000 V to 750.000 V 3 Hz – 5 Hz5 Hz –...

Frequency and Period Characteristics Frequency and Period Characteristics Accuracy Specifications ± ( % of reading ) [ 1 ] Function Range [ 3 ] Frequency 24 Hour [ 2 ] 23°C ± 1°C 1 Year23°C ± 5°C Temperature Coefficient/°C0°C – 18°C28°C – 55°C Frequency,Period [ 4 ] 100 mV to 750 V 3 Hz – 5 Hz5 Hz –...

General Information General Information General Specifications Power Supply: Power Line Frequency: Power Consumption:Operating Environment: Storage Environment:Rack Dimensions (HxWxD):Weight:Safety: EMC: Vibration and Shock: Warranty: 100 V / 120 V / 220 V / 240 V ± 10%. 45 Hz to 66 Hz and 360 Hz to...

Product Dimensions 348. 3 mm 88. 5 mm 212. 6 mm 261.1 mm 379.4 mm 103. 8 mm TOP Product Dimensions All dimensions areshown in millimeters. 8 Chapter 8 Specifications 223

To Calculate Total Measurement Error Each specification includes correction factors which account for errorspresent due to operational limitations of the multimeter. This sectionexplains these errors and shows how to apply them to your measurements.Refer to “Interpreting Multimeter Specifications,” ...

Understanding the “ % of range ” Error The range error compensatesfor inaccuracies that result from the function and range you select.The range error contributes a constant error, expressed as a percent ofrange, independent of the input signal level. The following table showsthe range error applied ...

Interpreting Multimeter Specifications This section is provided to give you a better understanding of the terminologyused and will help you interpret the multimeter’s specifications. Number of Digits and Overrange The “number of digits” specification is the most fundamental, andsometimes, the most c...

Resolution Resolution is the numeric ratio of the maximum displayed value dividedby the minimum displayed value on a selected range. Resolution isoften expressed in percent, parts-per-million (ppm), counts, or bits.For example, a 6 1 ⁄ 2 -digit multimeter with 20% overrange capability can display a ...

Transfer Accuracy Transfer accuracy refers to the error introduced by the multimeterdue to noise and short-term drift. This error becomes apparent whencomparing two nearly-equal signals for the purpose of “transferring”the known accuracy of one device to the other. 24-Hour Accuracy The 24-hour accur...

Configuring for Highest Accuracy Measurements The measurement configurations shown below assume that themultimeter is in its power-on or reset state. It is also assumed thatmanual ranging is enabled to ensure proper full scale range selection. DC Voltage, DC Current, and Resistance Measurements: • S...

Index “ 1 ⁄ 2 ” digit, 21, 54 2-wire ohms See two-wire ohms 34398A Cable Kit, 14934399A Adapter Kit, 1493478A compatibility, 16634812A BenchLink Software, 14-wire ohms See four-wire ohms “9.90000000E+37”, 61, 131 A a/d convertor, 55, 57abort measurement, 76ac bandwidth detector, 51, 214ac current co...