[SENSe:]TEMPerature:APERture

34980A

[SENSe:]TEMPerature:APERture

Syntax

[SENSe:]TEMPerature:APERture {<seconds>|MIN|MAX|DEF} [, (@<ch_list>)]

[SENSe:]TEMPerature:APERture? [{(@<ch_list>)|MIN|MAX}]

Description

This command enables the aperture mode and sets the integration time in seconds (called aperture time) for temperature measurements on the specified channels. If you omit the optional <ch_list> parameter, this command applies to the internal DMM, independent of any channels or a scan list.

You should use this command only when you want precise control of the integration time of the internal DMM. Otherwise, specifying integration time using NPLC (see [SENSe:]TEMPerature:NPLC command) executes faster and offers better noise rejection characteristics for values of NPLC greater than 1.

 

The following table shows which temperature transducers are supported by each of the multiplexer modules.

 

Thermocouple

RTD
2-Wire

RTD
4-Wire

Thermistor

 

34921A
Armature
Multiplexer

 Yes1

Yes

Yes

Yes

 

34922A
Armature Multiplexer

Yes2

Yes

Yes

Yes

 

34923A
Reed Multiplexer
(2-Wire)

Yes2,3

Yes4

Yes4

Yes5

 

34923A
Reed Multiplexer
(1-Wire)

Yes2,3

Yes4

No

Yes5

 

34924A
Reed Multiplexer

Yes2,3

Yes4

Yes4

Yes5

 

34925A
FET Multiplexer
(2-Wire)

Yes2

No

Yes5

No

 

34925A
FET Multiplexer
(1-Wire)

Yes2

No

No

No

 

1 Optional 34921T Terminal Block is required for thermocouple measurements with built-in internal reference junction.
2
A fixed or external reference junction temperature is required for thermocouple measurements with this module.
3
Impact of higher offset voltage specification (< 50 µV) must be taken into consideration.
4
1 kΩ or higher range used unless 100Ω series resistors are bypassed on module.
5
10 kΩ or higher range used for loads over approximately 300Ω due to series resistance of FET channels.

Parameters

Name

Type

Range of Values

Default Value

<seconds>

Numeric

Desired aperture time in seconds between 300 µs and 1 second, with 4 µs resolution.

MIN = 300 µs, MAX = 1 second

Aperture disabled.

<ch_list>

Numeric

One or more channels in the form (@sccc).

If <ch_list> is omitted, this command applies to the internal DMM.

Remarks

  • For the <seconds> parameter, you can substitute MIN or MAX for a numeric value. MIN selects the smallest value accepted, which gives the lowest resolution; MAX selects the largest value accepted, which gives the highest resolution.

  • If you omit the optional <ch_list> parameter, the configuration applies to the internal DMM, independent of any channels or a scan list (any existing scan list is not redefined). An error is generated if the internal DMM is not installed or is disabled.

  • Only the integral number of power line cycles (1, 2, 10, 20, 100, or 200 PLCs) provide normal mode (line frequency noise) rejection.

  • The CONFigure, MEASure?, and [SENSe:]TEMPerature:NPLC commands disable the aperture mode (these commands select an integration time in number of power line cycles). You can use the [SENSe:]TEMPerature:APERture:ENABled? command to query whether the aperture mode is currently enabled or disabled.

  • The aperture mode is disabled after a Factory Reset (*RST command). An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not change the setting.

Return Format

The query command returns the aperture time in the form "+1.00000000E-01" for each channel specified. Multiple responses are separated by commas. Note that if the aperture mode is currently disabled (see [SENSe:]TEMPerature:APERture:ENABled? command), the value returned will represent the previous value specified, not the actual integration time.

Examples

The following command enables the aperture mode and sets the aperture time to 300 ms on channels 3 and 13 in slot 1.

TEMP:APER 300E-03,(@1003,1013)

The following query returns the aperture time selected on channels 3 and 13 in slot 1.

TEMP:APER? (@1003,1013)
TEMP:APER:ENAB?  !Verify that aperture mode is enabled ("1")

Typical Response:

+3.00000000E-01,+3.00000000E-01
1

See Also

CONFigure:TEMPerature

[SENSe:]TEMPerature:APERture:ENABled?

[SENSe:]TEMPerature:NPLC