HP FET MULTIPLEXER E1351A/53A Comments

Comments Measuring Temperature with the HP El326B/El411B Multimeters. The HP E1326B/E1411B Multimeters can directly measure channels of single or multiple multiplexer modules. The multimeter automatically calculates the correct temperature for the specific thermistor or thermocouple type used. For more information, see the HP E1326B/E1411B Multimeter User’s Manual.

Thermocouple Compensated Measurements. The HP E1353A FET Multiplexer makes thermocouple compensated measurements. Thermocouple compensation accounts for the temperature inside the multiplexer terminal module, which can affect the thermocouple reading. Thermocouple compensated measurements are made with the HP E1326B/E1411B. More information on these types of measurements can be found in Hewlett-Packard Application Note 290, Practical Temperature Measurements.

High-Speed Temperature Measurements. High-speed temperature measurements can be made by measuring the thermocouple voltage, compensating the reading, and then converting the voltage to a temperature. The instrument configuration used for these types of measurements may include an E1326B/E1411B Multimeter and a FET multiplexer switchbox, or an external voltmeter used with the FET switchbox. The procedure for these types of measurements is:

1.Measure the resistance of the thermistor (channel 93) on the multiplexer terminal module (CLOSe(@cc93)).

2.Measure the thermocouple voltage on the multiplexer channel.

3.Convert the thermistor resistance to a temperature using the following equation:

t = 1.0 / (A + B * lnr + C * (lnr)3)calculate temperature

t = t - 273.15

convert Kelvin to Centigrade

where:

A = 0.00128463

B = 0.00023625

C = 9.2697E-8

lnr = natural log of the measured thermistor resistance

A, B, and C are the curve-fitting constants for the multiplexer’s 5K thermistor.

4.Convert the thermistor temperature (step 3) to a voltage using the reference table for the type of thermocouple used.

5.Subtract the voltage (step 4) from the thermocouple voltage measured in step 2. Convert the difference between the voltages to a temperature, again using the reference table for the type of thermocouple used.

6.Add the temperature (step 5) to the thermistor temperature computed in step 3 to obtain the result of the thermocouple measurement.

44 Using the HP E1351A/53A FET Multiplexer Modules

Chapter 3

Contents

Contents Page Page Page Page Page July 20 Page Reader Comment Sheet BUSINESS REPLY MAIL HEWLETT-PACKARDCOMPANY Page Getting Started with the HP E1351A/53A Using This Chapter FET Multiplexer Module Description Multimeter Connection Points Analog Bus Connector Page Switchbox and Scanning Voltmeter Configurations Digital Bus and Triggering Programming Language Initial Operation Configuring the HP E1351A/53A FET Multiplexer Modules Warnings and Cautions Multiplexer Card Numbers Setting the Address Switch Selecting the Interrupt Line Number Setting the Card ID Switch Connecting User Inputs Adding Signal Conditioning Components/Current Shunts Connecting Field Wiring Wiring a Terminal Module Connecting Multimeters and Signal Generators Analog Bus and Digital Bus Cables Page Using the HP E1351A/53A FET Multiplexer Modules Selecting Channels Page Multiplexer Commands Connecting Switchbox Channels to Direct Terminals Comments Connecting Switchbox Channels to Tree Terminals for Making Measurements Page Scanning a Range of Switchbox Channels Page Example: Making 2-WireOhms Measurements by Scanning Example: Making 4-WireOhms Measurements by Scanning Downloading a Scan List Scanning a Switchbox without a Downloaded Scan List Scanning a Switchbox with a Downloaded Scan List Scanning Voltmeter Configuration with HP E1326B Measuring Temperature Using Thermocouples (HP E1353A Module only) Comments Understanding the HP E1351A/53A FET Multiplexer Modules Commands for Scanning Switchbox Channels Using Scanning Trigger Sources Page Page Example: Scanning with External Instruments Using "Trig Out" and "Event In" Ports Using Stand-Alone Multimeter and Digital Bus Triggering Using Scanning Voltmeter Configuration and Digital Bus Triggering Using the Scan Complete Bit HP E1351A/53A 16-ChannelFET Multiplexer Command Reference Command Types Common Command Format SCPI Command Format Command Separator Abbreviated Commands Implied Commands Note SCPI Command Reference ABORt ARM DISPlay :MONitor:CARD :MONitor[:STATe] Monitoring Switchbox Channels: Selecting the Module to be Monitored: Monitor Mode on an HP 1301 Mainframe Display: Example Enabling the Monitor Mode INITiate Example Enabling Continuous Scans :CONTinuous Example Query Continuous Scanning State Starting the Scanning Cycle: ∙Stopping Scanning Cycles: See the ABORt command OUTPut [ROUTe:] Example Closing Multiplexer Channels CLOSe ∙ Query is Software Readback: The [ROUTe:]CLOSe? command Example Query Multiplexer Channel Closure OPEN Opening Multiplexer Channels OPEN ∙ Query is Software Readback: The [ROUTe:]OPEN? command Query Multiplexer Channel Open State SCAN ∙Scanning Operation: With a valid channel list Stopping Scan: Example Scanning Using External Instruments SCAN:MODE Order of Command Execution: Mode Description: Selecting the 4-Wire SCAN:MODE Example Query Scan Mode SCAN:PORT port Example Selecting the ABUS Port SCAN:PORT Example Query Scan Port SETTling[:TIME] Digital Bus Handshaking: Example Setting 16 μsec SETTling TIME SETTling[:TIME] Example Set and Query the SETTling TIME STATus :OPERation:ENABle SYSTem :CDEScription :CTYPe :ERRor TRIGger :SOURce ∙ Enabling the Trigger Source: The TRIGger:SOURce command Using the Using Digital Bus Trigger: Using External Trigger Inputs: Example Scanning Using External Triggers Scanning Using Bus Triggers :SOURce Example Query Trigger Source IEEE 488.2 Common Commands Command Quick Reference Page HP E1351A/53A FET Multiplexer Specifications Page HP E1351A/53A Register-Based Programming About This Appendix Register Addressing Page The Base Address A16 Address Space Outside the Command Module or Mainframe Register Descriptions Page Register Bit Descriptions Manufacturer ID Register Status/Control Register Scan Control Register Scan Channel Delay Register Scan Channel Configuration Register Configuration Bit (C1 - C0) Executing Commands OUTPut [ROUTe:] SYSTem TRIGger Register-BasedProgramming for Maximum Speed VLD A_D B_D decimal code: Page Multimeter Command and Parameter Opcodes Page Register-Based Programming Error Codes HP E1351A/53A FET Multiplexer Error Messages Page Index