[SENSe:]TEMPerature:ZERO:AUTO

Syntax | Description | Parameters | Remarks | Return Format | Examples

Syntax

[SENSe:]TEMPerature:ZERO:AUTO <mode> [, (@<ch_list>)]

[SENSe:]TEMPerature:ZERO:AUTO? [(@<ch_list>)]

Description

This command disables or enables the autozero mode 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.

When autozero is enabled (default), the instrument internally disconnects the input signal following each measurement, and takes a zero reading. It then subtracts the zero reading from the preceding reading. This prevents offset voltages present on the instrument's input circuitry from affecting measurement accuracy.

When autozero is disabled, the instrument takes one zero reading and subtracts it from all subsequent measurements. It takes a new zero reading each time you change the function, range, or integration time.

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
<mode>	Discrete	{OFF|ONCE|0|ON|1}	Autozero ON
<ch_list>	Numeric	One or more channels in the form (@sccc).	If <ch_list> is omitted, this command applies to the internal DMM.

Remarks

• Applies to temperature measurements only. Autozero is automatically enabled for 4-wire RTD measurements.

• The OFF and ONCE parameters have a similar effect. Autozero OFF does not issue a new zero measurement. Autozero ONCE issues an immediate zero measurement.

• 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.

• The autozero mode is set indirectly when you set the resolution and integration time. Autozero is automatically turned off when you select an integration time less than 1 PLC.

• You can set autozero from the remote interface only; you cannot directly set autozero from the front panel.

• The CONFigure and MEASure? commands automatically enable autozero.

• The autozero setting is stored in volatile memory and will be enabled (autozero ON) when power is turned off or after a Factory Reset (*RST command).

Return Format

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

Examples

The following command disables autozero on channels 3 and 13 in slot 1. With autozero disabled, a new zero measurement is not issued until the next time the instrument goes to the "wait-for-trigger" state.

TEMP:ZERO:AUTO OFF,(@1003,1013)

The following query returns the autozero settings on channels 3 and 13 in slot 1.

TEMP:ZERO:AUTO? (@1003,1013)

Typical Response:  0,0

See Also

CONFigure:TEMPerature

[SENSe:]CURRent[:DC]:ZERO:AUTO

[SENSe:]RESistance:ZERO:AUTO

[SENSe:]VOLTage[:DC]:ZERO:AUTO