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Chapter 2
Function Reference — Select_Signal
NI-DAQ FRM for PC Compatibles
2-372
©
 National Instruments Corporation
Select_Signal
Format
status = Select_Signal (deviceNumber, signal, source, sourceSpec)
Purpose
Chooses the source and polarity of a signal that the device uses (E Series and DAQArb 5411 
devices only). 
Parameters
Input   
Parameter Discussion for the E Series, DAQArb 5411, and DSA Devices
Legal ranges for the signalsource, and sourceSpec parameters are given in terms of 
constants that are defined in a header file. The header file you should use depends on which 
of the following languages you are using:
C programmers—
NIDAQCNS.H
 (
DATAACQ.H
 for LabWindows/CVI)
BASIC programmers—
NIDAQCNS.INC
 (Visual Basic for Windows programmers should 
refer to the 
 section in Chapter 1
, for more information.)
Pascal programmers—
NIDAQCNS.PAS
You can use the onboard DAQ-STC to select among many sources for various signals.
signal specifies the signal whose source you want to select. Table 2-35 shows the possible 
values for signal.
Note
Only the following signals are supported for the DAQArb 5411 devices:
ND_OUT_START_TRIGGER
ND_OUT_UPDATE
Name
Type
Description
deviceNumber
i16
assigned by configuration utility
signal
u32
signal to select the source and polarity
source
u32
the source of the signal
sourceSpec
u32
further signal specification (the polarity of the 
signal)