[SENSe:]CURRent:DC:APERture

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[SENSe:]CURRent:DC:APERture

Syntax

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

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

Description

This command enables the aperture mode and sets the integration time in seconds (called aperture time) for DC current measurements on the specified channels. If you omit the optional <ch_list> parameter, this command applies to the currently defined 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:]CURRent[:DC]:NPLC command) executes faster and offers better power line noise rejection characteristics for values of NPLC greater than 1.

Used With:

34901A 20 Channel Multiplexer (2/4-wire) Module (channels 21 and 22 only)

Parameters

Name Type Range of Values Default Value

<time> Numeric Desired aperture time in seconds between 400 µs and 1 second, with 4 µs resolution. MIN = 400 µs, MAX = 1 second Aperture disabled.

<ch_list> Channel List
One or more channels, as shown:

(@321) - channel 21 on the module in slot 300.

(@221:222) - channels 21 through 22 on the module in slot 200.

(@121:122,222,321:322) - channels 21 and 22 on the module in slot 100, channel 22 on the module in slot 200, and channels 21-22 on the module in slot 300.

Note that the channels must be of the form s21 and s22, where s is the first digit of the slot number.
If you omit the optional <ch_list> parameter, this command applies to the currently defined scan list.

Name	Type	Range of Values	Default Value
<time>	Numeric	Desired aperture time in seconds between 400 µs and 1 second, with 4 µs resolution. MIN = 400 µs, MAX = 1 second	Aperture disabled.
<ch_list>	Channel List	One or more channels, as shown: (@321) - channel 21 on the module in slot 300. (@221:222) - channels 21 through 22 on the module in slot 200. (@121:122,222,321:322) - channels 21 and 22 on the module in slot 100, channel 22 on the module in slot 200, and channels 21-22 on the module in slot 300. Note that the channels must be of the form s21 and s22, where s is the first digit of the slot number.	If you omit the optional <ch_list> parameter, this command applies to the currently defined scan list.

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.
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?, [SENSe:]CURRent[:DC]:NPLC, [SENSe:]CURRent[:DC]:RESolution commands automatically disable the aperture mode (these commands select an integration time in NPLCs).
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 returns the aperture time in the form "+1.00000000E-01" for each channel specified. Multiple responses are separated by commas.

Examples

The following command enables the aperture mode and sets the aperture time to 300 ms on channels 21 and 22 in slot 100.

CURR:DC:APER 300E-03,(@121,122)

The following query returns the aperture time selected on channels 21 and 22 in slot 100.

CURR:DC:APER? (@121,12) CURR:DC:APER:ENAB? !Verify that aperture mode is enabled ("1")

Typical Response: +3.00000000E-01,+3.00000000E-01

[SENSe:]CURRent:DC:APERture