Filter
Top Products
Chapter 2 Function Reference — SCAN_Op
©
National Instruments Corporation 2-299 NI-DAQ FRM for PC Compatibles
Note If you have selected external start triggering of the data acquisition operation, a
high-to-low edge at the STARTTRIG* pin on the I/O connector of the MIO-16 and
AT-MIO-16D, or the EXTTRIG* pin on the AT-MIO-16F-5, AT-MIO-64F-5, and
AT-MIO-16X initiates the data acquisition operation. If you are using an E Series
device, you need to apply a trigger that you select through the
Select_Signal or
DAQ_Config functions to initiate data acquisition. Be aware that if you do not
apply the start trigger,
SCAN_Op does not return control to your application.
Otherwise,
SCAN_Op issues a software trigger to initiate the data acquisition
operation.
If you have enabled pretrigger mode, the sample counter does not begin counting acquisitions
until you apply a signal at the stop trigger input. Until you apply this signal, the acquisition
remains in a cyclical mode, continually overwriting old data in the buffer with new data.
Again, if you do not apply the stop trigger,
SCAN_Op does not return control to your
application.
In any case, you can use
Timeout_Config to establish a maximum length of time for
SCAN_Op to execute.