how do I use a pretriggering mode with an analog hardware trigger?

[Garland]

I am trying to collect x number of points before and n number of points after an analog trigger (of specified level) is reached. I am using LabWindows with a PCI-6110 board. Any hints on the proper combination of functions to use is appreciated.

[Molly K]

Garland,

A good starting point would be the DAQsingleBufStopTrig.c example that is included when NI-DAQ is installed with support for LabWindows/CVI.

To have x points before the trigger and n points after the trigger, you configure a buffered data acquisition with a buffer size x+n and specify in DAQ_StopTrigger_Config that you want n points after the trigger. The result will be a buffer of data including x points before the trigger and n points after.

Regards,
Molly K.
National Instruments