HP 34970A Manual do Utilizador Página 1

HP 34970A Data Acquisition / Switch Unit User’s GuidePart Number 34970-90002October 1997For Safety information, Warranties, and Regulatory informat

HP 34907A Multifunction Module• Two 8-bit Digital Input/Output ports, 400 mA sink, 42 V open collector• 100 kHz Totalize input with 1 Vpp sensi

• The specified resolution is used for all measurements on the selectedchannel. If you have applied Mx+B scaling or have assigned alarms tothe selecte

• Remote Interface Operation: Specify the resolution in the same unitsas the measurement function, not in number of digits. For example,if the functi

Custom A/D Integration TimeIntegration time is the period of time that the instrument’s analog-to-digital (A/D) converter samples the input signal for

• The instrument selects 1 PLC when the measurement function ischanged and after a Factory Reset (*RST command). An InstrumentPreset (SYSTem:PRESet co

AutozeroWhen autozero is enabled (default), the instrument internallydisconnects the input signal following each measurement, and takes azero reading.

Temperature Measurement ConfigurationThis section contains information to help you configure the instrumentfor making temperature measurements. For mo

Thermocouple Measurements To connect a thermocouple to the module’s screw terminals, see page 21.• The instrument supports the following thermocouple

• Front-Panel Operation: To select the thermocouple function on theactive channel, choose the following items. TEMPERATURE , THERMOCOUPLETo selec

• Remote Interface Operation: You can use the MEASure? orCONFigure command to select the probe type and thermocouple type.For example, the following

RTD MeasurementsTo connect an RTD to the module’s screw terminals, see page 21.• The instrument supports RTDs with α = 0.00385 (DIN / IEC 751) or α =

In This Book Quick Start Chapter 1 helps you get familiar with a few of theinstrument’s front-panel features. This chapter also shows how toinstall t

• Remote Interface Operation: You can use the MEASure? orCONFigure command to select the probe type and RTD type.For example, the following statement

Thermistor MeasurementsTo connect a thermistor to the module’s screw terminals, see page 21.• The instrument supports 2.2 kΩ (44004), 5 kΩ (44007), an

Voltage Measurement ConfigurationTo connect voltage sources to the module’s screw terminals, see page 21.This section contains information to help you

• Remote Interface Operation: You can enable or disable the automaticinput resistance mode on the specified channels. With AUTO OFF(default), the inp

Resistance Measurement ConfigurationTo connect resistances to the module’s screw terminals, see page 21.This section contains information to help you

Current Measurement ConfigurationTo connect a current source to the module’s screw terminals, see page 21.This section contains information to help yo

• Front-Panel Operation: First, select the ac current (or ac voltage)function on the active channel. Then, go to the Advanced menu andselect the slow

Frequency Measurement ConfigurationTo connect an ac source to the module’s screw terminals, see page 21.Low Frequency Timeout The instrument uses thre

Mx+B ScalingThe scaling function allows you to apply a gain and offset to all readingson a specified multiplexer channel during a scan. In addition to

• During a Monitor operation, the gain and offset values are applied toall readings on the specified channel. • You can specify a custom label with up

ContentsChapter 1 Quick StartTo Prepare the Instrument for Use 17Installing HP BenchLink Data Logger Software 18 To Connect Wiring to a Module 20T

• Front-Panel Operation: The menu automatically guides you throughthe gain, offset, and measurement label settings. SET GAIN , SET OFFSET , SET L

Alarm LimitsThe instrument has four alarms which you can configure to alert youwhen a reading exceeds specified limits on a channel during a scan.You

• You can assign an alarm to any configured channel and multiplechannels can be assigned to the same alarm number. However,you cannot assign alarms on

• Alarms are logged in the alarm queue only when a reading crosses alimit, not while it remains outside the limit and not when it returnsto within lim

• For details on configuring alarms on the multifunction module, see “Using Alarms With the Multifunction Module” on page 130. • A Factory Reset (*RST

Viewing Stored Alarm DataIf an alarm occurs on a channel as it is being scanned, then that channel’salarm status is stored in reading memory as the re

• Remote Interface Operation: The following command reads data fromthe alarm queue (one alarm event is read and cleared each time thiscommand is exec

Using the Alarm Output LinesFour TTL alarm outputs are available on the rear-panel Alarmsconnector. You can use these hardware outputs to trigger exte

• You can control the slope of the pulse from the alarm outputs(the selected configuration is used for all four outputs). In thefalling edge mode, 0V

Using Alarms With the Multifunction ModuleYou can configure the instrument to generate an alarm when a specificbit pattern or bit pattern change is de

Chapter 4 Features and FunctionsSCPI Language Conventions 73Scanning 74Single-Channel Monitoring 93Scanning With External Instruments 95General Me

• Remote Interface Operation (Digital Input Channel): To assign thealarm number to report any alarm conditions on the specified digitalinput channels

Example: Configuring an Alarm on a Digital InputAssume that you want to generate an alarm when a binary pattern of“1000” is read on the upper four

Digital Input Operations The multifunction module (HP 34907A) has two non-isolated 8-bitinput/output ports which you can use for reading digital patte

• Front-Panel Operation: After selecting the port, press to readthe bit pattern (the least significant bit is on the right). The bitpattern read fr

Totalizer Operations The multifunction module has a 26-bit totalizer which can count TTLpulses at a 100 kHz rate. You can manually read the totalizer

• The maximum count is 67,108,863 (226-1). The count rolls over to “0”after reaching the maximum allowed value.• You can configure the totalizer to re

• Remote Interface Operation: To read the count from the specifiedtotalizer channel, send the following command. The count may bereturned with time s

Digital Output OperationsThe multifunction module (HP 34907A) has two non-isolated 8-bitinput/output ports which you can use for outputting digital pa

DAC Output Operations The multifunction module (HP 34907A) has two low-noise analogoutputs capable of outputting calibrated voltages between ±12 volts

System-Related Operations This section gives information on system-related topics such as storinginstrument states, reading errors, running a self-tes

Chapter 5 Remote Interface ReferenceSCPI Command Summary 181Simplified Programming Overview 201The MEASure? and CONFigure Commands 207Setting the

• The name can contain up to 12 characters. The first character mustbe a letter (A-Z), but the remaining 11 characters can be letters,numbers (0-9), o

Error Conditions When the front-panel ERROR annunciator turns on, one or morecommand syntax or hardware errors have been detected. A record ofup t

Self-Test A power-on self-test occurs automatically when you turn on theinstrument. This limited test assures you that the instrument andall installe

Display Control For security reasons or for a slight increase in scanning rates, you maywant to turn off the front-panel display. From the remote i

Real-Time System ClockDuring a scan, the instrument stores all readings and alarms withthe current time and date. The instrument stores the time and d

Firmware Revision Query The instrument has three microprocessors for control of various internalsystems. Each plug-in module also has its own on-bo

Relay Cycle CountThe instrument has a Relay Maintenance System to help you predictrelay end-of-life. The instrument counts the cycles on each relay in

• Front-Panel Operation: To read the count on the active channel,choose the following item and then turn the knob. To read the counton the internal D

SCPI Language Version Query The instrument complies with the rules and conventions of the presentversion of SCPI (Standard Commands for Programmable

Remote Interface Configuration This section gives information on configuring the instrument for remoteinterface communication. For more information on

Chapter 7 Application ProgramsExample Programs for Excel 7.0 321Example Programs for C and C++ 328Chapter 8 TutorialSystem Cabling and Connections

Remote Interface Selection The instrument is shipped with both an HP-IB (IEEE-488) interfaceand an RS-232 interface. Only one interface can be enable

Baud Rate Selection (RS-232) You can select one of eight baud rates for RS-232 operation. The rate isset to 57,600 baud when the instrument is shippe

Flow Control Selection (RS-232) You can select one of several flow control methods to coordinate thetransfer of data between the instrument and your

• Modem: This mode uses the DTR/DSR and RTS/CTS lines to controlthe flow of data between the instrument and a modem. When theRS-232 interface is sele

Calibration OverviewThis section gives a brief introduction to the calibration features of theinstrument and plug-in modules. For a more detailed disc

To Unsecure for Calibration You can unsecure the instrumenteither from the front panel or over the remote interface. The instrumentis secured when sh

To Secure Against Calibration You can secure the instrument eitherfrom the front panel or over the remote interface. The instrument issecured when sh

Calibration Message The instrument allows you to store one message in calibration memoryin the mainframe. For example, you can store such information

Calibration Count You can query the instrument to determine how many calibrations havebeen performed. Note that your instrument was calibrated before

Factory Reset State The table below shows the state of the instrument after a FACTORY RESETfrom the Sto/Rcl menu or *RST command from the remote inter

1Quick Start 1

Instrument Preset StateThe table below shows the state of the instrument after a PRESET fromthe Sto/Rcl menu or SYSTem:PRESet command from the remote

Multiplexer Module Default SettingsThe table below shows the default settings for each measurementfunction on the multiplexer modules. When you config

Module OverviewThis section gives a description of each plug-in module, includingsimplified schematics and block diagrams. A wiring log is also includ

HP 34901A 20-Channel MultiplexerThis module is divided into two banks of 10 channels each. Two additionalfused channels are available for making dire

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch Name Function Comments01020304050607080910H COML COM 1

HP 34902A 16-Channel MultiplexerThis module is divided into two banks of eight channels each. All 16channels switch both HI and LO inputs, thus provi

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch Name Function Comments0102030405060708H COML COM 09 * 1

HP 34903A 20-Channel ActuatorThis module contains 20 independent, SPDT (Form C) latching relays.Screw terminals on the module provide access to the N

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch NO NC COM Comments0102030405060708091011121314151617181920NO

HP 34904A 4x8 Matrix SwitchThis module contains 32 two-wire crosspoints organized in a 4-row by8-column configuration. You can connect any combinatio

Quick StartOne of the first things you will want to do with your instrument is tobecome acquainted with the front panel. We have written the exercises

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Row Name Comments1234Column Name Comments12345678Example:

HP 34905A/6A Dual 4-Channel RF MultiplexersThese modules consist of two independent 4-to-1 multiplexers.The channels in each bank are organized in a

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch Name Comments11121314COM121222324COM2Refer to the diagrams

HP 34907A Multifunction Module This module combines two 8-bit ports of digital input/output, a 100 kHztotalizer, and two ±12 analog outputs. For gre

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch Name Comments01 (DIO 1) Bit 0Bit 1Bit 2Bit 3Bit 4Bit 5Bit

HP 34908A 40-Channel Single-Ended MultiplexerThe module is divided into two banks of 20 channels each. All of the40 channels switch HI only, with a

Module ReferenceWIRING LOG Slot Number: ❒ 100 ❒ 200 ❒ 300Ch Name Function Comments010203040506070809101112131415161718192

5Remote Interface Reference 5

Remote Interface Reference• SCPI Command Summary, starting on page 181• Simplified Programming Overview, starting on page 201• The MEASure? and CONFig

SCPI Command SummaryThroughout this manual, the following conventions are used forSCPI command syntax for remote interface programming:• Square bracke

To Prepare the Instrument for Use1 Check the list of supplied items.Verify that you have received the following items with your instrument.If anything

Rules for Using scan_list and ch_list ParametersBefore you can initiate a scan, you must set up a scan list to include alldesired multiplexer or digit

Scan Measurement Commands (see page 226 for more information)MEASure :TEMPerature? {TCouple|RTD|FRTD|THERmistor|DEF} ,{<type>|DEF}[,1[,{&

Scan Configuration Commands (see page 226 for more information)ROUTe :SCAN (@<scan_list>) :SCAN? :SCAN:SIZE?TRIGger :SOURce {BUS|IMMediate

Scan Statistics Commands (see page 233 for more information)CALCulate :AVERage:MINimum? [(@<ch_list>)] :AVERage:MINimum:TIME? [(@<ch_list

Scanning With an External Instrument (see page 239 for more information)ROUTe :SCAN (@<scan_list>) :SCAN? :SCAN:SIZE?TRIGger :SOURce {BUS|

Temperature Configuration Commands (see page 219 for more information)CONFigure :TEMPerature {TCouple|RTD|FRTD|THERmistor|DEF} ,{<type>|D

Voltage Configuration Commands (see page 223 for more information)CONFigure :VOLTage:DC [{<range>|AUTO|MIN|MAX|DEF} [,<resolution>|

Resistance Configuration Commands (see page 224 for more information)CONFigure :RESistance [{<range>|AUTO|MIN|MAX|DEF} [,<resolution&g

Current Configuration Commands (see page 224 for more information) Valid only on channels 21 and 22 on the HP 34901A multiplexer module.CONFigure :

Frequency and Period Configuration Commands (see page 214 for more information)CONFigure :FREQuency [{<range>|AUTO|MIN|MAX|DEF} [,<res

Installing HP BenchLink Data Logger SoftwareIf you ordered the HP 34970A with the internal DMM, then theHP BenchLink Data Logger software is included.

Mx+B Scaling Commands (see page 244 for more information)CALCulate :SCALe:GAIN <gain>[,(@<ch_list>)] :SCALe:GAIN? [(@<ch_list>)]

Alarm Limit Commands (see page 247 for more information)OUTPut :ALARm[1|2|3|4]:SOURce (@<ch_list>) :ALARm[1|2|3|4]:SOURce?CALCulate :LIMit:U

Digital Input Commands (see page 255 for more information)Ch 01DIO (LSB)Ch 02DIO (MSB)Ch 03TotalizerCh 04DACCh 05DACCONFigure:DIGital:BYTE (@<sca

Digital Output Commands (see page 258 for more information)Ch 01DIO (LSB)Ch 02DIO (MSB)Ch 03TotalizerCh 04DACCh 05DACSOURce :DIGital:DATA[:{BYTE|WO

Scan Triggering Commands (see page 228 for more information)TRIGger :SOURce {BUS|IMMediate|EXTernal|ALARm1|ALARm2|ALARm3|ALARm4|TIMer} :SOURce?TRI

System-Related Commands (see page 264 for more information)SYSTem :DATE <yyyy>,<mm>,<dd> :DATE? :TIME <hh>,<mm>,<

Interface Configuration Commands (see page 269 for more information)SYSTem:INTerface {GPIB|RS232}SYSTem:LOCalSYSTem:REMoteSYSTem:RWLock Status S

Calibration Commands (see page 292 for more information)CALibration?CALibration:COUNt?CALibration :SECure:CODE <new_code> :SECure:STATe {OF

IEEE 488.2 Common Commands *CLS*ESR?*ESE <enable_value>*ESE?*IDN?*OPC*OPC?*PSC {0|1}*PSC?*RST*SAV {0|1|2|3|4|5}*RCL {0|1|2|3|4|5}*STB?*SRE <

Simplified Programming OverviewThis section gives an overview of the basic techniques used to programthe HP 34970A over the remote interface. This sec

The HP 34970A combines precision measurement capability withflexible signal connections for your production and development testsystems. Three module

Creating Installation Floppy DisksYou have the option to create an installation on floppy disks from theCD-ROM installation utility. This utility is p

Using the MEASure? CommandThe MEASure? command provides the easiest way to program theinstrument for scanning. However, this command does not offer mu

Using the range and resolution Parameters With the MEASure? and CONFigure commands, you can select themeasurement function, range, and resolution all

Using the READ? Command The READ? command changes the state of the scan trigger system fromthe “idle” state to the “wait-for-trigger” state. Scanning

Example: Using MEASure? The following program segment shows how to use the MEASure?command to make a measurement on one channel. This exampleconfigu

Example: Using CONFigure With INITiate and FETCh? The following program segment is similar to the previous example but ituses INITiate to place the

The MEASure? and CONFigure CommandsBoth the MEASure? and CONFigure commands reset all measurementparameters to their default values. For more informat

MEASure:TEMPerature? {RTD|FRTD},{85|91|DEF} [,1[,<resolution>|MIN|MAX|DEF}]] ,(@<scan_list>)Configure the specified channels for 2-wir

MEASure:RESistance?MEASure:FRESistance? [{<range>|AUTO|MIN|MAX|DEF} [,<resolution>|MIN|MAX|DEF}],] (@<scan_list>)Configure the s

MEASure:DIGital:BYTE? (@<scan_list>)Configure the instrument to read the specified digital input channels onthe multifunction module and immedia

CONFigure Command Syntax CONFigure:TEMPerature {TCouple},{B|E|J|K|N|R|S|T|DEF} [,1[,<resolution>|MIN|MAX|DEF}]] ,(@<scan_list>)Confi

To Connect Wiring to a Module 6 mm 20 AWG Typical Channel Number:Slot Channel 5 Install the module into mainframe.Wiring Hints...• For detailed

CONFigure:VOLTage:DCCONFigure:VOLTage:AC [{<range>|AUTO|MIN|MAX|DEF} [,<resolution>|MIN|MAX|DEF}],] (@<scan_list>)Configure the

CONFigure:FREQuency CONFigure:PERiod [{<range>|AUTO|MIN|MAX|DEF} [,<resolution>|MIN|MAX|DEF}],] (@<scan_list>)Configure the spe

Setting the Function, Range, and ResolutionSee also “General Measurement Configuration” in chapter 4 startingon page 98.• For 4-wire measurements, the

[SENSe:] VOLTage:DC:RANGe {<range>|MIN|MAX}[,(@<ch_list>)] VOLTage:AC:RANGe {<range>|MIN|MAX}[,(@<ch_list>)] RESistance:RAN

[SENSe:] VOLTage:DC:RANGe:AUTO? [(@<ch_list>)] VOLTage:AC:RANGe:AUTO? [(@<ch_list>)] RESistance:RANGe:AUTO? [(@<ch_list>)] FRESi

[SENSe:] VOLTage:DC:APERture {<time>|MIN|MAX}[,(@<ch_list>)] RESistance:APERture {<time>|MIN|MAX}[,(@<ch_list>)] FRESistanc

[SENSe:] TEMPerature :NPLC {0.02|0.2|1|2|10|20|100|200|MIN|MAX}[,(@<ch_list>)] VOLTage:DC :NPLC {0.02|0.2|1|2|10|20|100|200|MIN|MAX}[,(@

Temperature Configuration CommandsSee also “Temperature Measurement Configuration” in chapter 4 startingon page 106. General Temperature Commands UNI

Thermocouple Commands [SENSe:]TEMPerature:TRANsducer :TCouple:TYPE {B|E|J|K|N|R|S|T}[,(@<ch_list>)] :TCouple:TYPE? [(@<ch_list>)]Selec

[SENSe:]TEMPerature:TRANsducer :TCouple:CHECk {OFF|ON}[,(@<ch_list>)] :TCouple:CHECk? [(@<ch_list>)]Disable or enable the thermocouple c

DC Voltage / AC Voltage / Frequency ThermocoupleThermocouple Types: B, E, J, K, N, R, S, TSee page 351 for thermocouple color codes.Ranges

RTD Commands [SENSe:]TEMPerature:TRANsducer :RTD:TYPE {85|91}[,(@<ch_list>)] :RTD:TYPE? [(@<ch_list>)] :FRTD:TYPE {85|91}[,(@<ch_li

Voltage Configuration CommandsSee also “Voltage Measurement Configuration” in chapter 4 starting onpage 113.INPut :IMPedance:AUTO {OFF|ON}[,(@<ch_

Resistance Configuration CommandsSee also “Resistance Measurement Configuration” in chapter 4 startingon page 115.[SENSe:] RESistance:OCOMpensated {O

Frequency Configuration CommandsSee also “Frequency Measurement Configuration” in chapter 4 starting onpage 118.[SENSe:] FREQuency:RANGe:LOWer {3|20|

Scanning OverviewSee also “Scanning” in chapter 4 starting on page 74.The instrument allows you to combine a DMM (either internal or external)with mul

• You can use either the internal DMM or an external DMM to makemeasurements of your configured channels. However, the instrumentallows only one scan

Scanning Commands ROUTe :SCAN (@<scan_list>) :SCAN?Select the channels to be included in the scan list. To start the scan,use the INITiate or

TRIGger :TIMer {<seconds>|MIN|MAX} :TIMer?Set the scan-to-scan interval (in seconds) for measurements on thechannels in the scan list. This co

ROUTe :CHANnel:DELay:AUTO {OFF|ON}[,(@<ch_list>)] :CHANnel:DELay:AUTO? [(@<ch_list>)]Disable or enable an automatic channel delay on the

Reading Format Commands During a scan, the instrument automatically adds a time stamp toall readings and stores them in non-volatile memory. Each re

To Set the Time and Date All readings during a scan are automatically time stamped and storedin non-volatile memory. In addition, alarm data is time s

FORMat :READing:TIME {OFF|ON} :READing:TIME?Disable (default) or enable the inclusion of a time stamp with dataproduced by READ?, FETCh?, or other q

Scan Statistics Commands While a scan is running, the instrument automatically stores theminimum and maximum readings and calculates the average for

CALCulate:AVERage:AVERage? [(@<ch_list>)]Calculate the mathematical average of all readings taken on each of thespecified channels since the sta

Scan Memory Commands You can store up to 50,000 readings in non-volatile memory duringa scan. Readings are stored only during a scan and all reading

SYSTem:TIME:SCAN?Read the time at the start of the scan. This command is not affected bythe FORMat:READ:TIME:TYPE command. Returns the time in the for

Single-Channel Monitoring OverviewIn the Monitor function, the instrument takes readings as often as it canon a single channel, even during a scan. Th

ROUTe :MONitor (@<channel>) :MONitor?Select the channel to be monitored. To turn on the monitor function,use the ROUT:MON:STATE ON command (se

Scanning With an External InstrumentIf your application doesn’t require the built-in measurement capabilitiesof the HP 34970A, you can order it withou

ROUTe :SCAN (@<scan_list>) :SCAN?Select the channels to be included in the scan list. To start the scan,use the INITiate or READ? command. To

TRIGger :TIMer {<seconds>|MIN|MAX} :TIMer?Set the scan-to-scan interval (in seconds) for measurements on thechannels in the scan list. This co

To Configure a Channel for Scanning Any channel that can be “read” by the instrument can also be includedin a scan. This includes readings on multiple

ROUTe :CHANnel:ADVance:SOURce {EXTernal|BUS|IMMediate} :CHANnel:ADVance:SOURce? This command is valid only when the internal DMM is disabled orremov

ROUTe :CHANnel:FWIRe {OFF|ON} [,(@<ch_list>)] :CHANnel:FWIRe? [(@<ch_list>)]This command is valid only when the internal DMM is disabled

Mx+B Scaling OverviewSee also “Mx+B Scaling” in chapter 4 starting on page 119. The scaling function allows you to apply a gain and offset to all read

Mx+B Scaling Commands CALCulate :SCALe:GAIN <gain>[,(@<ch_list>)] :SCALe:GAIN? [(@<ch_list>)]Set the gain (“M”) for scaled readi

CALCulate:SCALe:OFFSet:NULL (@<ch_list>)Make an immediate null measurement on the specified channels andstore it as the offset (“B”) for subsequ

Alarm System OverviewSee also “Alarm Limits” in chapter 4 starting on page 122.The instrument has four alarms which you can configure to alert youwhen

• You can assign an alarm to any configured channel and multiplechannels can be assigned to the same alarm number. However,you cannot assign alarms on

• Four TTL alarm outputs are available on the rear-panel Alarmsconnector. You can use these hardware outputs to trigger externalalarm lights, sirens,

Alarm Limit Commands OUTPut :ALARm[1|2|3|4]:SOURce (@<ch_list>) :ALARm[1|2|3|4]:SOURce? Assign the alarm number to report any alarm condition

CALCulate :LIMit:LOWer <value>[,(@<ch_ list>)] :LIMit:LOWer? [(@<ch_list>)]Set the lower limit for alarms on the specified channel

Note: Press to sequentially step through the scan list and take ameasurement on each channel (readings are not stored in memory).This is an easy wa

Alarm Output Commands Four TTL alarm outputs are available on the rear-panel Alarmsconnector. You can use these hardware outputs to trigger external

Digital I/O Alarm Commands See also “Using Alarms With the Multifunction Module” in chapter 4starting on page 130. CALCulate :COMPare:TYPE {EQUal|N

CALCulate :COMPare:MASK <mask>[,(@<ch_list>)] :COMPare:MASK? [(@<ch_list>)]Specify the mask pattern for comparisons on the specifi

Digital Input CommandsSee also “Digital Input Operations” in chapter 4 starting on page 133.MEASure:DIGital:BYTE? (@<scan_list>)Configure the in

Totalizer CommandsSee also “Totalizer Operations” in chapter 4 starting on page 135.MEASure:TOTalize? {READ|RRESet} ,(@<scan_list>)Configure the

[SENSe:] TOTalize:SLOPe {NEGative|POSitive}[,(@<ch_list>)] TOTalize:SLOPe? [(@<ch_list>)]Configure the totalizer to count on the rising

Digital Output CommandsSOURce :DIGital:DATA[:{BYTE|WORD}] <data> ,(@<ch_list>) :DIGital:DATA[:{BYTE|WORD}]? (@<ch_list>)Output an

Switch Control CommandsROUTe :CLOSe (@<ch_list>) :CLOSe:EXCLusive (@<ch_list>) :CLOSe? (@<ch_list>)Close the specified channels o

ROUTe :CHANnel:FWIRe {OFF|ON} [,(@<ch_list>)] :CHANnel:FWIRe? [(@<ch_list>)]This command is valid only when the internal DMM is disabled

State Storage CommandsThe instrument has six storage locations in non-volatile memory tostore instrument states. The locations are numbered 0 through

To Copy a Channel ConfigurationAfter configuring a channel to be included in the scan list, you cancopy that same configuration to other channels in t

MEMory:STATe :NAME {1|2|3|4|5} [,<name>] :NAME? {1|2|3|4|5}Assign a name to the specified storage location (you cannot assign aname to locatio

MEMory:STATe :RECall:AUTO {OFF|ON} :RECall:AUTO?Disable or enable (default) the automatic recall of the power-down statefrom storage location “0” wh

System-Related CommandsSee also “System-Related Operations” in chapter 4 starting on page 140.SYSTem:DATE <yyyy>,<mm>,<dd>Set the in

*IDN?Read the instrument’s identification string. The instrument returnsthree numbers for the system firmware. The first number is thefirmware revisio

DISPlay {OFF|ON}DISPlay?Disable or enable the front-panel display. When disabled, the entirefront-panel display goes dark and all display annunciators

INSTrument :DMM {OFF|ON} :DMM?Disable or enable the internal DMM. When you change the state of theinternal DMM, the instrument issues a Factory Rese

SYSTem:ERRor?Query the instrument’s error queue. A record of up to 10 errors is storedin the instrument’s error queue. Errors are retrieved in first-i

Interface Configuration CommandsSee also “Remote Interface Configuration” in chapter 4 starting on page 150.SYSTem:INTerface {GPIB|RS232}Select the re

RS-232 Interface ConfigurationSee also “Remote Interface Configuration” in chapter 4 on page 150.This section contains information to help you use the

RS-232 Flow Control ModesYou can select one of several flow control methods to coordinate thetransfer of data between the instrument and your computer

To Close a ChannelOn the multiplexer and switch modules, you can close and open individualrelays on the module. However, note that if you have already

RS-232 Data Frame FormatA character frame consists of all the transmitted bits that make up asingle character. The frame is defined as the bits from t

If your computer has a 9-pin serial port with a male connector, use thecable included with the instrument (if you ordered the internal DMM).If you nee

Modem CommunicationsThis section gives details on communicating with the instrument froma remote PC using a modem. To communicate over the phone lines

The SCPI Status SystemThis section describes the structure of the SCPI status system used bythe HP 34970A. The status system records various condition

HP 34970A Status SystemTot OvflMem Ovfl Alarm Register Questionable Data Register Status Byte Register STAT:QUES:COND?Curr Ovld Standard Ope

The Status Byte RegisterThe Status Byte register group reports conditions from the otherregister groups. Data in the instrument’s output buffer is imm

Using Service Request (SRQ) and Serial Poll You must configure your computer to respond to the IEEE-488 servicerequest (SRQ) interrupt to use this cap

Using the Message Available Bit (MAV)You can use the Status Byte “Message Available” bit (bit 4) to determinewhen data is available to read into your

The Questionable Data RegisterThe Questionable Data register group provides information about thequality of the instrument’s measurement results. Any

The Questionable Data event register is cleared when:• You execute a *CLS (clear status) command.• You query the event register using the STATus:QUES:

If the Instrument Does Not Turn OnUse the following steps to help solve problems you might encounterwhen turning on the instrument. If you need more h

The Standard Event RegisterThe Standard Event register group reports the following types ofinstrument events: power-on detected, command syntax error

The Standard event register is cleared when:• You execute the *CLS (clear status) command.• You query the event register using the *ESR? command.The S

The Alarm RegisterThe Alarm register group is used to report the status of the fourinstrument alarm limits. Any or all of these alarm conditions can b

The Standard Operation RegisterThe Standard Operation register group is used to report when theinstrument is scanning. Any or all of these conditions

Status System CommandsAn application program is included in chapter 7 which shows the use ofthe Status System Registers. Refer to page 330 for more in

Questionable Data Register Commands See the table on page 280 for the register bit definitions.STATus:QUEStionable:CONDition?Query the condition reg

Standard Event Register Commands See the table on page 282 for the register bit definitions.*ESR?Query the event register in this register group. Th

Alarm Register Commands See the table on page 284 for the register bit definitions.STATus:ALARm:CONDition?Query the condition register in this regis

Standard Operation Register Commands See the table on page 285 for the register bit definitions.STATus:OPERation:CONDition?Query the condition regis

DATA:POINts:EVENt:THReshold <num_rdgs>DATA:POINts:EVENt:THReshold?Set a bit in the event register when the specified number of readingshave been

1 Remove the power cord. Remove the fuse-holder assembly from the rear panel. 2 Remove the line-voltage selector from the assembly. 3

Calibration CommandsFor an overview of the calibration features of the instrument, refer to“Calibration Overview” in chapter 4 starting on page 155. F

CALibration:SECure:STATe {OFF|ON},<code>CALibration:SECure:STATe?Unsecure or secure the instrument for calibration. The security codemay contain

Service-Related CommandsINSTrument :DMM {OFF|ON} :DMM?Disable or enable the internal DMM. When you change the state of theinternal DMM, the instrume

*RSTReset the instrument to the Factory configuration. See “Factory ResetState” on page 160 in chapter 4 for a complete listing of the instrument’sFac

An Introduction to the SCPI LanguageSCPI (Standard Commands for Programmable Instruments) is anASCII-based instrument command language designed for te

Command Format Used in This ManualThe format used to show commands in this manual is shown below: VOLTage:DC:RANGe {<range>|MINimum|MAXimum}[,(

Command Separators A colon ( : ) is used to separate a command keyword from a lower-levelkeyword. You must insert a blank space to separate a paramete

Querying Parameter SettingsYou can query the current value of most parameters by adding aquestion mark ( ? ) to the command. For example, the followin

SCPI Parameter Types The SCPI language defines several different data formats to be used inprogram messages and response messages. Numeric Parameters

String Parameters String parameters can contain virtually any set ofASCII characters. A string must begin and end with matching quotes;either with a

The Front Panel at a Glance 1 State Storage / Remote Interface Menus2 Scan Start / Stop Key3 Measurement Configuration Menu4 Scaling Configuratio

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.

Using Device ClearDevice Clear is an IEEE-488 low-level bus message which you can useto return the instrument to a responsive state. Different program

6Error Messages 6

Error Messages • Errors are retrieved in first-in-first-out (FIFO) order. The first errorreturned is the first error that was stored. Errors are clear

Execution Errors -101 Invalid character An invalid character was found in the command string. You may haveused an invalid character such as #, {, $,

-114 Header suffix out of rangeA header suffix is the number that can be appended to the end of somecommand headers. This error is generated if an inv

-168 Block data not allowedData was sent to the instrument in SCPI definite length block format butthis command does not accept this format. Example:

-230 Data staleA FETCh? or DATA:REMove? command was received but internalreading memory was empty. The readings retrieved may be invalid.-310 Sys

Instrument Errors111 Channel list: slot number out of rangeThe specified slot number is invalid. The channel number has theform (@scc), where s is th

221 Settings conflict: calculate limit state forced offIf you plan to use scaling on a channel which will also use alarms, be sureto configure the sc

261 Not able to execute while scan initiatedWhile a scan is running, you cannot change any parameters that affectthe scan (channel configuration, scan

To Rack Mount the InstrumentYou can mount the instrument in a standard 19-inch rack cabinet usingone of three optional kits available. Instructions an

303 Module not able to perform requested operationA command was received which is not valid for the specified module.This error is most commonly gener

501 I/O processor: isolator framing error502 I/O processor: isolator overrun error511 Communications: RS-232 framing error512 Communications: RS-2

Self-Test Errors The following errors indicate failures that may occur during a self-test.Refer to the HP 34970A Service Guide for more information.60

Calibration Errors The following errors indicate failures that may occur during a calibration.Refer to the HP 34970A Service Guide for more informat

710 Cal: full scale correction out of range720 Cal: DCV offset out of range 721 Cal: DCI offset out of range 722 Cal: RES offset out of range 7

Plug-In Module Errors901 Module hardware: unexpected data received902 Module hardware: missing stop bit903 Module hardware: data overrun904 Module

7ApplicationPrograms 7

Application ProgramsThis chapter contains several example programs to help you developprograms for your specific measurement application. Chapter 5,“R

Example Programs for Excel 7.0This section contains two example programs written using Excel macros(Visual Basic ® for Applications) to control the HP

Excel 7.0 Example: takeReadings Macro ’""""""""""""""""""&

To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and flange kit 5063-9212. Be sure to use the support rails inside the rac

Excel 7.0 Example: Port Configuration Macro Option Explicit’ Declarations for VISA.DLL’ Basic I/O OperationsPrivate Declare Function viOpenDefaultRM

Sub OpenPort() ’""""""""""""""""""""""

Excel 7.0 Example: ScanChannels Macro ’""""""""""""""""""&

’ Set up the scan trigger parameters after configuring the channels in the scan list ’ using the CONFigure command. The following commands con

Sub makeDataTable(Channel As Integer, columnIndex As Integer) ’ This routine will take the parsed data in row ’1’ for a channel and put it into a

Example Programs for C and C++The following C programming examples show you how to send andreceive formatted I/O. For more information on non-formatte

C / C++ Example: dac_out.c /* dac_out.c/**************************************************************************** Required: HP 34907A Multifunct

C / C++ Example: stat_reg.c /* stat_reg.c/****************************************************************************** Required: VISA library.

do{ /* Stay in loop until the srqFlag goes negative */ index = 1; for (count = 0; count <45; count++) { index = 0; printf(&quo

8Tutorial 8

2Front-PanelOverview 2

TutorialThis chapter describes methods that you can use to reduce errors thatcan affect your measurements. You will also find information to helpyou b

System Cabling and ConnectionsThis section describes methods to reduce measurement errors that canbe introduced by your system cabling. Many system ca

• Cable Resistance – Varies with wire gauge size and cable length.Use the largest gauge wire possible and try to keep the cable lengthsas short as pos

Grounding TechniquesOne purpose of grounding is to avoid ground loops and minimize noise.Most systems should have at least three separate ground retur

Shielding TechniquesShielding against noise must address both capacitive (electrical) andinductive (magnetic) coupling. The addition of a grounded shi

Sources of System Cabling ErrorsRadio Frequency Interference Most voltage-measuring instrumentscan generate false readings in the presence of large,

Thermal EMF Errors Thermoelectric voltages are the most commonsource of error in low-level dc voltage measurements. Thermoelectricvoltages are genera

Noise Caused by Ground Loops When measuring voltages in circuitswhere the internal DMM and the device-under-test are both referencedto a common earth

Low-Level AC Measurement Errors When measuring ac voltagesless than 100 mV, be aware that these measurements are especiallysusceptible to errors intr

Measurement FundamentalsThis section explains how the HP 34970A makes measurements anddiscusses the most common sources of error related to these meas

Front-Panel OverviewThis chapter introduces you to the front-panel keys and menu operation.This chapter does not give a detailed description of every

Rejecting Power-Line Noise Voltages A desirable characteristic ofan integrating analog-to-digital (A/D) converter is its ability to rejectspurious si

Temperature MeasurementsA temperature transducer measurement is typically either a resistanceor voltage measurement converted to an equivalent tempera

RTD Measurements An RTD is constructed of a metal (typicallyplatinum) that changes resistance with a change in temperature in aprecisely known way. Th

Thermocouple Measurements A thermocouple converts temperatureto voltage. When two wires composed of dissimilar metals are joined,a voltage is generat

An ice bath is used to create a known reference temperature (0 °C).Once the reference temperature and thermocouple type are known,the temperature of t

To make a more accurate measurement, you should extend the coppertest leads of the internal DMM closer to the measurement and hold theconnections to t

In some measurement situations, however, it would be nice to removethe need for an ice bath (or any other fixed external reference). To dothis, an iso

T/C Type Pos (+) Lead Neg (-) LeadTemperatureRangeProbeAccuracy CommentsBU.S.BritishDINJapaneseFrenchPlatinum-30% Rhodium Gray N/A Red Red N/APla

Sources of Error in Thermocouple MeasurementsReference Junction Error A thermocouple is typically formed bywelding or soldering two wires together to

Shunt Impedance The insulation used for thermocouple wire andextension wire can be degraded by high temperatures or corrosiveatmospheres. These break

Front-Panel Menu ReferenceThis section gives an overview of the front-panel menus. The menus aredesigned to automatically guide you through all parame

DC Voltage MeasurementsTo make a useful dc meter, a “front-end” is required to condition theinput before the analog-to-digital conversion. Signal cond

Sources of Error in DC Voltage Measurements Common Mode Rejection Ideally, the internal DMM is completelyisolated from earth-referenced circuits. How

Noise Caused by Injected Current Residual capacitances in theinstrument’s power transformer cause small currents to flow from theLO terminal of the i

Loading Errors Due to Input Resistance Measurement loadingerrors occur when the resistance of the device-under-test (DUT) is anappreciable percentage

Loading Errors Due to Input Bias Current The semiconductordevices used in the input circuits of the internal DMM have slightleakage currents called bi

AC Voltage MeasurementsThe main purpose of an ac “front end” is to change an ac voltage inputinto a dc voltage which can be measured by the ADC. Signa

True RMS AC Measurements True RMS responding multimetersmeasure the “heating” potential of an applied voltage. Unlike an“average responding” measureme

Making High-Speed AC Measurements The internal DMM’sac voltage and ac current functions implement three low-frequencyfilters. These filters allow you

Sources of Error in AC Voltage MeasurementsMany of the errors associated with dc voltage measurements also applyto ac voltage measurements. Additional

Example: Calculating Measurement Error Calculate the approximate measurement error for a pulse train inputwith a crest factor of 3 and a fundamenta

Configure the advanced measurement features on displayed channel.• Set the integration time for measurements on the displayed channel. • Set the ch

AC Loading Errors In the ac voltage function, the input of theinternal DMM appears as a 1 MΩ resistance in parallel with 150 pFof capacitance. The ca

Low-Level AC Measurement Errors When measuring ac voltagesless than 100 mV, be aware that these measurements are especiallysusceptible to errors intr

Measurements Below Full Scale You can make the most accurateac measurements when the internal DMM is at full scale of the selectedrange. Autoranging

Current MeasurementsCurrent measurements are allowed only on the HP 34901A module.An ammeter senses the current flowing through its input connections

Sources of Error in DC Current Measurements When you connect the internal DMM in series with a test circuit tomeasure current, a measurement error is

Resistance MeasurementsAn ohmmeter measures the dc resistance of a device or circuit connectedto its input. Resistance measurements are performed by s

The 4-wire ohms method is used in systems where lead resistances canbecome quite large and variable and in automated test applicationswhere cable leng

Offset Compensation Most connections in a system use materialsthat produce small dc voltages due to dissimilar metal-to-metal contact(thermocouple ef

Sources of Error in Resistance MeasurementsExternal Voltages Any voltages present in the system cabling orconnections will affect a resistance measur

Strain Gage Measurements Although the instrument does not directly support strain measurements,you can measure a strain gage using a 4-wire resistanc

To Monitor a Single ChannelYou can use the Monitor function to continuously take readings on a singlechannel, even during a scan. This feature is usef

For more information on strain gages, refer to “Practical Strain GageMeasurements” (HP Application Note 290-1). This application note isalso available

Making Strain Gage Measurements A Wheatstone bridge iscommonly used to enable instruments with low-sensitivity measuringcapabilities to measure small

Frequency and Period MeasurementsThe internal DMM uses a reciprocal counting technique to measurefrequency and period. This method generates constant

Sources of Error in Frequency and Period MeasurementsThe internal DMM’s ac voltage measurement section performs inputsignal conditioning. All frequenc

Low-Level Signal Multiplexing and SwitchingLow-level multiplexers are available in the following types: one-wire,2-wire, and 4-wire. The following se

One-Wire (Single-Ended) Multiplexers On the HP 34908A multiplexer, all of the 40 channels switch the HIinput only, with a common LO for the module. Th

Four-Wire Multiplexers You can make 4-wire ohms measurements using the HP 34901A andHP 34902A multiplexers. For a 4-wire ohms measurement, the channel

Signal Routing and Multiplexing When used stand-alone for signal routing (not scanning or connected tothe internal DMM), multiple channels on the HP 3

Sources of Error in Multiplexing and SwitchingNoise can be coupled inside a switch by the drive circuitry, by switchthermal EMFs, or by coupling among

The HP 34901A and HP 34902A multiplexers have an additional relay,called a bank switch or tree switch, which helps reduce channel-to-channel noise (Ca

To Set a Scan IntervalYou can set the instrument’s internal timer to automatically scan at aspecific interval (e.g., start a new scan sweep every 10 s

Actuators and General-Purpose SwitchingThe HP 34903A Actuator provides 20 independent, isolated SPDT(single-pole, double-throw) or Form C switches. Th

Snubber Circuits Whenever a relay contact opens or closes, electrical breakdown orarching can occur between the contacts. This can cause high-frequenc

The maximum value for Rp is usually made equal to the load resistance RL.Therefore, the limits on Rp can be stated as: VImax < Rp < RLNote

Using Attenuators Provisions have been made on the HP 34903A circuit board forinstalling simple attenuators or filter networks. An attenuator iscompos

Matrix SwitchingA matrix switch connects multiple inputs to multiple outputs andtherefore offers more switching flexibility than a multiplexer. Use am

Combining Matrices You can combine two or more matrix switches to provide more complexswitching. For example, the HP 34904A provides a 4-row by 8-colu

RF Signal MultiplexingA special type of multiplexer is the RF multiplexer. This type of multiplexeruses special components to maintain a 50Ω or 75Ω im

Sources of Error in RF Switching Impedance mismatching can cause a variety of errors in an RFmultiplexing system. These errors can cause distorted w

Multifunction ModuleDigital InputThe HP 34907A module has two non-isolated 8-bit input/output portswhich you can use for reading digital patterns. • Y

Digital OutputThe HP 34907A module has two non-isolated 8-bit input/output portswhich you can use for outputting digital patterns. You can combine the

To Apply Mx+B Scaling to MeasurementsThe scaling function allows you to apply a gain and offset to all readingson a specified multiplexer channel duri

Using an External Pull-Up In general, an external pull-up is required only when you want to setthe output “high” value greater than TTL levels. For ex

TotalizerThe HP 34907A module has a 26-bit totalizer which can count pulses ata 100 kHz rate. You can manually read the totalizer count or you canconf

• You can control when the totalizer actually records counts by providinga gate signal (G and G terminals on the module). A TTL high signalapplied to

Voltage (DAC) OutputThe HP 34907A module has two analog outputs capable of outputtingcalibrated voltages between ±12 volts with 16 bits of resolution.

DAC Errors The output of a DAC varies with temperature. If possible, you shouldoperate the instrument at a stable temperature and as close as possible

Relay Life and Preventative MaintenanceThe HP 34970A Relay Maintenance System automatically counts thecycles on each relay in the instrument and store

Relay LifeAs a relay is used, the contacts begin to wear and the resistance of theclosed contacts increases. The initial contact resistance of a relay

Switching FrequencyRelay contacts heat up as they switch significant power. The heat isdissipated through the leads and the body of the relay. As you

9Specifications• DC, Resistance, and Temperature Accuracy Specifications, on page 404• DC Measurement and Operating Characteristics, on page 405• AC A

DC, Resistance, and Temperature Accuracy Specifications± ( % of reading + % of range ) [1]Includes measurement error, switching error, and transducer

The Front-Panel Menus at a GlanceSeveral of the front-panel keys guide you through menus to configurevarious parameters of the instrument (see previou

To Configure Alarm LimitsThe instrument has four alarms which you can configure to alert youwhen a reading exceeds specified limits on a channel durin

DC Measurement and Operating Characteristics DC Measurement Characteristics [1] DC VoltageMeasurement Method: A/D Linearity: Input Resistance:

AC Accuracy Specifications ± ( % of reading + % of range ) [1]Includes measurement error, switching error, and transducer conversion errorFunction Ra

AC Measurement and Operating CharacteristicsAC Measurement Characteristics [1] True RMS AC Voltage Measurement Method: Crest Factor:Additional Crest

Measurement Rates and System Characteristics Single Channel Measurement Rates [1] [2]FunctionDCV, 2-Wire Ohms:Thermocouple:RTD, Thermistor:ACV:Frequ

Module Specifications HP 34901A, 34902A, 34908A, 34903A, 34904A Multiplexer Actuator MatrixGeneral 34901A 34902A 34908A 34903A

Module Specifications HP 34905A, 34906A RF MultiplexerGeneral 34905A 34906A Number of Channels Dual 1x450ΩDual 1x475Ω Open/Close Speed 60/sM

Typical AC Performance Graphs HP 34905A, 34906A Insertion Loss (50 )Insertion Loss (75 )VSWR (75 )Crosstalk (50 )Crosstalk (75 )Direct to Modu

Module Specifications HP 34907A Digital Input / OutputPort 1, 2:Vin(L):Vin(H):Vout(L):Vout(H):Vout(H) Max:Alarming: Speed LatencyRead/Writ

Product and Module Dimensions 91.9315.6ModuleTOPAll dimensions are shownin millimeters.103.6 mm254.4 mm374.0 mm348.3 mm212.6 mm88.5 mm 9Chapter 9 Spe

To Calculate Total Measurement ErrorEach specification includes correction factors which account for errorspresent due to operational limitations of t

4 Set the limit value.The alarm limit values are stored in non-volatile memory for thespecified channels. The default values for the high and low limi

Understanding the “ % of range ” Error The range error compensatesfor inaccuracies that result from the function and range you select.The range error

Interpreting Internal DMM SpecificationsThis section is provided to give you a better understanding of theterminology used and will help you interpret

Resolution Resolution is the numeric ratio of the maximum displayed value dividedby the minimum displayed value on a selected range. Resolution isofte

24-Hour Accuracy The 24-hour accuracy specification indicates the internal DMM’s relativeaccuracy over its full measurement range for short time inter

Configuring for Highest Accuracy Measurements The measurement configurations shown below assume that the internalDMM is in its Factory Reset state. It

Index Warnings HP 34901A, 165 HP 34902A, 167 HP 34903A, 169 HP 34904A, 171 HP 34908A, 176“ 1⁄2 ” digit, 100, 4164W annunciator, 450Ω RF switchi

autozero definition, 105 vs. integration time, 105average responding error, 360average, during scan, 75AWG, wire gauge size, 336B“B” (Mx+B sca

channel numbering HP 34901A, 164 HP 34902A, 166 HP 34903A, 168 HP 34904A, 170 HP 34905A, 172 HP 34906A, 172 HP 34907A, 174 HP 34908A, 176chass

decimal format (digital input), 42, 133declaration of conformity, inside rear coverdefault delays (channel delays), 89delay (channel delay), 88devi

FORMat:READ:ALARm command, 231FORMat:READ:CHANnel command, 231FORMat:READ:TIME command, 232, 264FORMat:READ:UNIT command, 232four-wire multiplexers

To Read a Digital Input PortThe multifunction module (HP 34907A) has two non-isolated 8-bitinput/output ports which you can use for reading digital pa

HP 34908A module channel numbering, 176 description, 176 screw terminal diagram, 177 simplified schematic, 176, 177 wiring log, 177 module ove

line voltage factory setting, 27 fuse, 27 selection, 27 selector module, 5, 28loading errors ac voltage, 364 dc input resistance, 357 inp

Nname, stored states, 48noise caused by ground loops, 341noise rejection, normal mode, 103nominal impedance, cabling, 335nominal resistance (RTD)

READ? command, 79, 204, 230 description, 202 examples, 205reading format, 87readings memory, storing alarms, 122readings, viewing, 24, 90real-ti

scan interval default value, 38, 81 resolution, 81 setting from front panel, 81 setting from remote, 81Scan key, 24, 78scan list adding

snubber circuitry, 385software (BenchLink Data Logger) creating floppy disks, 19 installation, 18, 19 on-line help, 19 overview, 6 system r

TTEMP:TRAN:FRTD:RES command, 222TEMP:TRAN:FRTD:TYPE command, 222TEMP:TRAN:RTD:RES command, 222TEMP:TRAN:RTD:TYPE command, 222TEMP:TRAN:TC:CHECk comman

UUNIT:TEMP command, 106, 219units temperature, 106, 219 with readings, 87unsecure calibration, 156Utility key, 36Vvaristor, 386vertical bar (|),

DECLARATION OF CONFORMITY according to ISO / IEC Guide 22 and EN 45014 Manufacturer’s Name: Hewlett-Packard CompanyLoveland Manufacturing Ce

Copyright  1997Hewlett-Packard CompanyAll Rights Reserved. Printing HistoryEdition 1, June 1997Edition 2, October 1997New editions are completerevisi

To Write to a Digital Output PortThe multifunction module (HP 34907A) has two non-isolated 8-bitinput/output ports which you can use for outputting di

To Read the Totalizer CountThe multifunction module (HP 34907A) has a 26-bit totalizer which cancount pulses at a 100 kHz rate. You can manually read

To Output a DC VoltageThe multifunction module (HP 34907A) has two analog outputs capableof outputting calibrated voltages between ±12 volts.1Select a

To Configure the Remote InterfaceThe instrument is shipped with both an HP-IB (IEEE-488) interfaceand an RS-232 interface. Only one interface can be e

RS-232 Configuration 1 Select the RS-232 interface.562 Select the baud rate.Select one of the following: 1200, 2400, 4800, 9600, 19200, 3840

To Store the Instrument StateYou can store the instrument state in one of five non-volatile storagelocations. A sixth storage location automatically h

3System Overview 3

Display Annunciators To review the display annunciators, hold down the key as you turn on the instrument. SCAN MON VIEWCONFIG ADRS RMTERRO

System OverviewThis chapter provides an overview of a computer-based system anddescribes the parts of a data acquisition system. This chapter is divid

The system configuration shown on the previous page offers thefollowing advantages:• You can use the HP 34970A to perform data storage, data reduction

Measurement SoftwareA variety of software is available to configure your data acquisitionhardware and manipulate and display your measurement data.Dat

The HP 34970A Data Acquisition / Switch UnitAs shown below, the logic circuitry for the HP 34970A is divided intotwo sections: earth-referenced and f

Plug-In ModulesThe HP 34970A offers a complete selection of plug-in modules to giveyou high-quality measurement, switching, and control capabilities.T

System CablingThe plug-in modules have screw-terminal connectors to make it easy toconnect your system cabling. The type of cabling that you use to co

Transducers and SensorsTransducers and sensors convert a physical quantity into an electricalquantity. The electrical quantity is measured and the res

Signal Routing and SwitchingThe switching capabilities of the plug-in modules available with theHP 34970A provide test system flexibility and expandab

Multiplexer Switching Multiplexers allow you to connect one ofmultiple channels to a common channel, one at a time. A simple 4-to-1multiplexer is sho

Matrix Switching A matrix switch connects multiple inputs tomultiple outputs and therefore offers more switching flexibility than amultiplexer. Use a

The Rear Panel at a Glance WARNINGFor protection from electrical shock, the power cord ground must not bedefeated. If only a two-contact electrical ou

Measurement InputThe HP 34970A allows you to combine a DMM (either internal or external)with multiplexer channels to create a scan. During a scan, the

Signal Conditioning, Ranging, and Amplification Analog inputsignals are multiplexed into the internal DMM’s signal-conditioningsection – typically com

Main Processor The main processor, located in the floating logicsection, controls the input signal conditioning, ranging, and the ADC.The main proces

You can configure the event or action that controls the onset of eachsweep through the scan list (a sweep is one pass through the scan list):• You can

Scanning With External InstrumentsIf your application doesn’t require the built-in measurement capabilitiesof the HP 34970A, you can order it without

The Multifunction ModuleThe multifunction module (HP 34907A) adds two additional measurementinput capabilities to the system: digital input and event

Totalizer The multifunction module has a 26-bit totalizer which cancount pulses at a 100 kHz rate. You can manually read the totalizercount or you ca

Control OutputIn addition to signal routing and measurement, you can also use theHP 34970A to provide simple control outputs. For example, you cancont

Voltage (DAC) Output The multifunction module has two analogoutputs capable of outputting calibrated voltages between ±12 volts with16 bits of resolu

The Actuator / General-Purpose SwitchYou can think of the HP 34903A Actuator as a control output because itis often used to control external power dev

HP BenchLink Data Logger Software at a GlanceHP BenchLink Data Logger is a Windows-based application designedto make it easy to use the HP 34970A with

4Features and Functions 4

Features and Functions You will find that this chapter makes it easy to look up all the detailsabout a particular feature of the HP 34970A. Whether y

SCPI Language ConventionsThroughout this manual, the following conventions are used forSCPI command syntax for remote interface programming:• Square b

ScanningThe instrument allows you to combine a DMM (either internal or external)with multiplexer channels to create a scan. During a scan, the instrum

• Each time you start a new scan, the instrument clears all readings(including alarm data) stored in reading memory from the previousscan. Therefore,

• When you add a digital read (multifunction module) to a scan list,that port is dedicated to the scan. The instrument issues a CardReset to make that

Power Failure• When shipped from the factory, the instrument is configured toautomatically recall the power-down state when power is restored.In this

Adding Channels to a Scan ListBefore you can initiate a scan, you must configure the channels to bescanned and set up a scan list (these two operation

To Build a Scan List From the Remote Interface:• The MEASure?, CONFigure, and ROUTe:SCAN commands contain ascan_list parameter which defines the list

Scan IntervalYou can configure the event or action that controls the onset of eachsweep through the scan list (a sweep is one pass through the scan li

The Plug-In Modules at a GlanceFor complete specifications on each plug-in module, refer to the modulesections in chapter 9. HP 34901A 20-Channel

• You can set the scan interval to any value between 0 secondsand 99:59:59 hours (359,999 seconds), with 1 ms resolution. • Once you have initiated th

Scan Once In this configuration, the instrument waits for either afront-panel key press or a remote interface command before sweepingthrough the scan

External Scanning In this configuration, the instrument sweepsthrough the scan list once each time a low-going TTL pulse is receivedon the rear-panel

Scanning on Alarm In this configuration, the instrument sweeps thescan list once each time a reading crossing an alarm limit on a channel.You can als

• Remote Interface Operation: The following program segment configuresthe instrument to scan when an alarm occurs. TRIG:SOURCE ALARM1 Select the

Scan CountYou can specify the number of times the instrument will sweep throughthe scan list. When the specified number of sweeps have occurred, thesc

Reading FormatDuring a scan, the instrument automatically adds a time stamp toall readings and stores them in non-volatile memory. Each reading isstor

Channel DelayYou can control the pace of a scan sweep by inserting a delay betweenmultiplexer channels in the scan list (useful for high-impedance orh

Automatic Channel Delays If you do not specify a channel delay, the instrument selects a delayfor you. The delay is determined by function, range, int

• Front-Panel Operation: CH DELAY AUTO• Remote Interface Operation: The following command enables anautomatic channel delay on channel 01. ROU

HP 34903A 20-Channel Actuator / General-Purpose Switch• 300 V, 1 A actuation and switching• SPDT (Form C) latching relays• Breadboard area for c

• Readings acquired during a Monitor are not stored in memory(however, all readings from a scan in progress at the same time arestored in memory). • T

• Remote Interface Operation: The following command retrieves storedreadings from memory (the readings are not erased). FETCH?Use the following comm

Single-Channel MonitoringIn the Monitor function, the instrument takes readings as often as it canon a single channel, even during a scan. This featur

• In the Alarm Scan configuration (see “Scanning on Alarm” on page 84),the instrument sweeps the scan list once each time a reading crossesan alarm li

Scanning With External InstrumentsIf your application doesn’t require the built-in measurement capabilitiesof the HP 34970A, you can order it without

In this configuration, you must set up a scan list to include all desiredmultiplexer or digital channels. Channels which are not in the list areskippe

• An externally-controlled scan can also include a read of a digital portor a read of the totalizer count on the multifunction module. Whenthe channel

General Measurement Configuration This section contains general information to help you configure theinstrument for making measurements during a scan.

• For frequency and period measurements, the instrument uses one“range” for all inputs between 3 Hz and 300 kHz. The range parameteris required only t

Measurement ResolutionResolution is expressed in terms of number of digits the instrument canmeasure or display on the front panel. You can set the re