Measurement Computing Data Acquisition Systems rev.10.4 - Manual (Page 76)

daqAdcSetAcq
Also See: daqAdcArm, daqAdcDisarm, daqAdcSetTrig
Format
daqAdcSetAcq(handle, mode, preTrigCount, postTrigCount)
Purpose
daqAdcSetAcq configures the acquisition mode and the pre- and post-trigger scan durations.
Parameter Summary
Parameter Type Description
handle DaqHandleT Handle to the device for which the ADC acquisition is to
be configured
mode DaqAdcAcqMode Selects the mode of the acquisition
preTrigCount DWORD Number of pre-trigger acquisition scans to be collected
postTrigCount DWORD Number of post-trigger acquisition scans to be collected
Parameter Values
handle: obtained from the daqOpen function.
mode: see table below
preTrigCount: valid value range from 1 to 100,000
postTrigCount: valid values range from 1 to 4,294,967,295; however, memory limitations may apply
Parameter Type Definitions
mode-(DaqAdcAcqMode)
Definition Description
DaamNShot Triggers and continues acquisition until specified number of post-trigger scans is
reached, then disarms acquisition
DaamNShotRearm Triggers and continues acquisition until specified number of post-trigger scans is
reached, then re-arms acquisition with original parameters (WaveBook only)
DaamInfinitePost Once triggered, collects scans until disarmed by the daqAdcDisarm function
DaamPrePost Collects specified number pre-trigger scans, triggers acquisition, collects specified
number of post-trigger scans, and disarms
Returns
DerrNoError No error
Function Usage
Configuring the Acquisition Mode
The mode parameter defines certain characteristics of the data acquisiton. Depending on its parameter values,
mode
can be used to detemine if pre- or post-trigger data will be recorded, how many pre- or post-trigger scans
will be collected, and when the acquisition will terminate. The acquistion mode may also specify that the
acquisition should be automatically re-armed (using the same acquisition parameters) once the initial
acquisition has completed. Each block of aquired trigger scans is placed into the buffer sequentially. The
preTrigCount
and postTrigCount parameters specify the respective durations of the pre-trigger and
post-trigger acquisition states.
Parameter values for mode can be defined as follows:
DaamNShot -- Once triggered, this mode continues acquisition until the specified post-trigger count has been
satisfied. Once the post-trigger count has been satisfied, the acquisition will automatically disarm. This mode
specifies no pre-trigger and will stop acquiring once the post-trigger scan count has been satisfied. If the
acquisition is stopped by means other than reaching the scan count, the stop trigger detection will occur after
count scans are acquired.
4.2-20 Daq API Command Reference 988594 Programmer’s Manual