VTI Instruments EX1629 - Vtex1629_Measure_Confidence

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EX1629 Command Set 201
vtex1629_measure_confidence
FUNCTION PROTOTYPE
ViStatus vtex1629_measure_confidence (ViSession vi, ViInt32 confValue, ViInt32 numberOfChannels, ViInt32
_VI_FAR channels[],ViInt32 sampleCount, ViReal64 _VI_FAR returnedValues[], ViPInt32
numReturnedValues);
FUNCTION PARAMETERS
vi = contains a session handle to the instrument. This handle is obtained by the function and remains valid until the
session is closed.
confValue = defines the confidence source for which to query. Valid input range: 0, 1, or 2.
numberOfChannels = a return integer value indicating the number of channels currently included in the scan list.
Valid return values: 1 to 48.
channel[] = an integer input array that specifies the channel for which the configuration will be returned. Valid input
values: 0 to 47.
sampleCount = an integer input value indicating the number of measurements to average.
returnedValues[]=a real return array of the measured values.
numReturnedValues = an integer return value that indicates the number of measured values returned in the
returnedValues array.
DATA ITEM RESET VALUE
Not applicable to this function.
DESCRIPTION
This function measures the indicated bridge parameter to indicate measurement confidence. The confValue
parameter can assume the following values:
Decimal
Value
Hex
Value
#define
confValue Description
0
0x00
CONFIDENCE_BUFFERED_INPUT
Buffered input
1
0x01
CONFIDENCE_EXCITATION_CURRENT
Excitation current
2
0x02
CONFIDENCE_COMMON_MODE_VOLTAGE
Common mode voltage
The “Buffered Input” confidence source measures the Main ADC input with GAIN = 1. This is useful to verify the
Main ADC value and the gain settings. The “Excitation Current” measures the current from the excitation source.
Finally, the “Common Mode Voltage” measures the common mode voltage appearing across the inputs of the
differential amplifier in the main ADC.
The returnedValues[] array returns the values measured. These values are placed in the array according to the
channels[] array passed to the function. In other words, for every channel number in channels[], there will be a
corresponding measurement in returnedValues.
EXAMPLE
ViSession instrumentHandle;
ViStatus status = VI_SUCCESS;
ViInt32 numOfChannels = MAX_CHANNELS;
ViInt32 channels[MAX_CHANNELS];
ViInt32 sampleCount = 100;
ViReal64 returnedVals[MAX_CHANNELS];
ViInt32 numOfReturnedValues = 0;
int i = 0;
for(i = 0; i < numOfChannels; i++) {
channels[i] = i;
}