[SENSe:]VOLTage[:DC]:IMPedance:AUTO

34980A

[SENSe:]VOLTage[:DC]:IMPedance:AUTO

Syntax

[SENSe:]VOLTage[:DC]:IMPedance:AUTO <mode> [, (@<ch_list>)]

[SENSe:]VOLTage[:DC]:IMPedance:AUTO? [(@<ch_list>)]

Description

This command disables or enables the automatic input resistance mode for dc voltage measurements on the specified channels. Normally, the instrument's input resistance is fixed at 10 MΩ for all dc voltage ranges to minimize noise pickup. To reduce the effects of measurement loading errors, you can set the input resistance to greater than 10 GΩ for the 100 mVdc, 1 Vdc, and 10 Vdc ranges. If you omit the optional <ch_list> parameter, this command applies to the internal DMM, independent of any channels or a scan list.

Used With:

  • 34921A through 34925A Multiplexer Modules

Parameters

Name

Type

Range of Values

Default Value

<mode>

Boolean

{OFF|0|ON|1}

OFF|0 (fixed at 10 MΩ for all ranges)

<ch_list>

Numeric

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

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

Remarks

  • 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.

  • With AUTO OFF (default), the input resistance is fixed at 10 MΩ for all ranges. With AUTO ON, the input resistance is set to >10 GΩ for the 100 mV, 1 V, and 10 V ranges.  

Input Resistance Setting

Input Resistance for:
100 mV, 1 V, 10 V ranges

Input Resistance for:
100 V, 300 V ranges

VOLTage:IMPedance:AUTO OFF

10 MΩ

10 MΩ

VOLTage:IMPedance:AUTO ON

> 10 GΩ

10 MΩ

  • The CONFigure and MEASure? commands automatically select AUTO OFF (fixed at 10 MΩ for all ranges).

  • The instrument selects 10 MΩ (fixed input resistance on all dc voltage ranges) after a Factory Reset ( *RST command). An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not change the input resistance setting.

Return Format

The query command returns "0" (OFF) or "1" (ON) for each channel specified. Multiple responses are separated by commas.

Examples

The following command enables the automatic input resistance mode (AUTO ON) on channels 3 and 13 in slot 1.

VOLT:IMP:AUTO ON,(@1003,1013)

The following query returns the automatic input resistance mode settings on channels 3 and 13 in slot 1.

VOLT:IMP:AUTO? (@1003,1013)

Typical Response:  1,1

See Also

CONFigure[:VOLTage][:DC]