National Instruments Welding System 321645c-01 Manuel D’Utilisation
Chapter 2
Function Reference — SCAN_Start
NI-DAQ FRM for PC Compatibles
2-314
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National Instruments Corporation
If you have selected external start triggering of the data acquisition operation, a high-to-low
edge at the STARTTRIG* I/O connector input on the MIO-16/16D, or the EXTTRIG*
connector on the MIO-F-5/16X initiates the data acquisition operation after the
edge at the STARTTRIG* I/O connector input on the MIO-16/16D, or the EXTTRIG*
connector on the MIO-F-5/16X initiates the data acquisition operation after the
SCAN_Start
call is complete. Otherwise,
SCAN_Start
issues a software trigger to initiate the data
acquisition operation before returning.
Note
If your application calls
DAQ_Start
or
SCAN_Start
, always ensure that you
call
DAQ_Clear
before your application terminates and returns control to the
operating system. Unless you make this call (either directly, or indirectly through
DAQ_Check
or
DAQ_DB_Transfer
), unpredictable behavior can result.
You must use the
SCAN_Setup
and
SCAN_Start
functions as a pair. Making a single call to
SCAN_Setup
with multiple calls to
SCAN_Start
will fail and return error noSetupError.
If you have an SC-2040 connected to your DAQ device, NI-DAQ will ignore the
sampTimebase and sampInterval parameters. NI-DAQ automatically supplies these
parameters to optimally match your hardware.
sampTimebase and sampInterval parameters. NI-DAQ automatically supplies these
parameters to optimally match your hardware.
If you select sampTimebase = 0 and scanTimebase = 0, you must use the same source for
both. This requirement is enforced on most MIO devices through hardware because you
connect both timebases to the SOURCE5 I/O connector pin. On E Series devices, if you use
the
both. This requirement is enforced on most MIO devices through hardware because you
connect both timebases to the SOURCE5 I/O connector pin. On E Series devices, if you use
the
Select_Signal
function to specify the source of an external sample and external scan
timebase, you must specify the same source for both timebases.