Chapter 2 Function Reference — Select_Signal
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National Instruments Corporation 2-385 NI-DAQ FRM for PC Compatibles
Parameter Discussion for the 6602 Devices
Legal ranges for the signal, source, and sourceSpec parameters are given in terms of
constants that are defined in a header file.
• B ASIC programmers—NIDAQCNS.INC (Visu al Basic for Windows pro grammers should
refer to the Programming Language Considerations section in Chapter1, Using the
NI-DAQ Functions, for more information.
• Pascal programmers—NIDAQCNS.PAS
Note Use the signal parameter to specify the signal whose source you want to select. The
following table shows the possible values for signal.
Legal values for source and sourceSpec depend on the signal and are shown in the following
tables:
signal = ND_RTSI_0 through ND_RTSI_6 and ND_RTSI_CLOCK
signal = ND_START_TRIGGER
Table 2-36. Legal Parameters for the 6602 Devices
Group Signal Description
All of the RTSI lines ND_RTSI_0 through
ND_RTSI_6 and
ND_RTSI_CLOCK
Selects a counter for output on a
RTSI line
The triggering input for the
counter ND_START_TRIGGER Selects a source for the counter’s
hardware arming or triggering
source
source sourceSpec
ND_NONE (default) ND_DONT_CARE
ND_LOW ND_DONT_CARE
ND_HIGH ND_DONT_CARE
ND_GPCTR0_OUTPUT through ND_GPCTR7_OUTPUT ND_DONT_CARE
source sourceSpec
ND_LOW ND_LOW_TO_HIGH
ND_HIGH ND_LOW_TO_HIGH