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Chapter 2 Function Reference — AI_VRead_Scan
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National Instruments Corporation 2-19 NI-DAQ FRM for PC Compatibles
AI_VRead_Scan
Format
status = AI_VRead_Scan (deviceNumber, reading)
Purpose
Returns readings in volts for all analog input channels selected by SCAN_Setup (E Series
devices only with or without the SC-2040 accessory).
Parameters
Input
Output
Parameter Discussion
reading is an array of readings from each sampled analog input channel. The length of the
reading array is equal to the number of channels selected in the
SCAN_Setup numChans
parameter. NI-DAQ uses values you have specified in
SCAN_Setup through the gains
parameter for computing voltages. If you have attached an SC-2040 or SC-2043-SG to your
DAQ device, NI-DAQ also uses values you have specified in
SC_2040_Config (through
the sc2040gain parameter) or
Set_DAQ_Device_Info (a fixed gain of 10) for computing
voltages.
If you have SCC modules connected, NI-DAQ also uses the SCC module gain for computing
voltages.
Using This Function
AI_VRead_Scan samples the analog input channels selected by SCAN_Setup, at half
the maximum rate your DAQ hardware permits.You must use the
SCAN_Setup function prior
to invoking this function.
You cannot use external signals to control A/D conversion timing and use this function at the
same time.
Name Type Description
deviceNumber i16 assigned by configuration utility
Name Type Description
reading [f64] voltage readings from each sampled analog
input channel