GxDmmGetAutoZero

Purpose

Returns the auto zero status

Syntax

GxDmmGetAutoZero (nHandle, pdwAutoZeroMode , pnStatus)

Parameters

Name
Type
Comments
nHandle
SHORT
Handle for a GX2065 board.
pdwAutoZeroMode
PDWORD
Returns the status of the Auto Zero function.
0. GXDMM_AUTO_ZERO_ON: The DMM will perform an auto zero every time a measurement is taken.
1. GXDMM_AUTO_ZERO_OFF: The DMM will not auto zero when a measurement is taken.
2. GXDMM_AUTO_ZERO_NOW: The DMM will perform an auto zero calculation as soon as this command is received.
pnStatus
PSHORT
Returned status: 0 on success, negative number on failure.

Comments

To help maintain stability and accuracy over time and changes in temperature, the DMM periodically measures internal voltages corresponding to offsets (zero) and amplifier gains. These measurements are used in an algorithm to calculate the reading of the input signal. This process is known as auto zeroing.

When auto zero is disabled, the offset, gain, and internal temperature measurements are not performed. This increases the measurement speed (reading rate). However, the zero, gain, and temperature reference points will eventually drift resulting in less accurate readings of the input signal.

It is recommended that auto zero only be disabled for short periods of time.

An auto zero can also be forced by using the GXDMM_AUTO_ZERO_NOW mode.

Example

The following example gets the auto zero status:

 

SHORT nHandle, nStatus;

DOUBLE dMeasurement;

GxDmmGetAutoZero (nHandle, &dMeasurement, &nStatus);

 

See Also

GxDmmSetAutoZero, GxDmmSetFunction, GxDmmGetFunction, GxDmmSetRange, GxDmmGetRange, GxDmmGetErrorString