Chapter 2 Function Reference — Config_DAQ_Eve nt_Message
©
National Instruments Corporation 2-71 NI-DAQ FRM for PC Compatibles
Config_DAQ_Event_Message
Format
status = Config_DAQ_Event_Message (deviceNumber, mode, chanStr, DAQEvent,
DAQTrigVal0, DAQTrigVal1, trigSkipCount,
preTrigScans, postTrigScans, handle, message,
callbackAddr)
Purpose
Notifies NI-DAQ applications when the status of an asynchronous DAQ operation (initiated
by a call to DAQ_Start, DIG_Block_Out, WFM_Group_Control, and so on) meets certain
criteria you specify. Notification is done through the Windows PostMessage API and/or a
callback function.
Certain DAQEvent options are best suited for low-speed transfers, because they require the
processor to examine each data point as it is acquired or transferred. These options include
DAQEvents 3 through 9. For these options, you cannot use DMA, and the processor has to
do more work. The processing burden increases in direct proportion to the speed of the
asynchronous operation.
Parameters
Input
Name Type Description
deviceNumber i16 assigned by configuration utility
mode i16 add or remove a message
chanStr STR channel string
DAQEvent i16 event criteria
DAQTrigVal0 i32 general-purpose trigger value
DAQTrigVal1 i32 general-purpose trigger value
trigSkipCount u32 number of triggers to skip
preTrigScans u32 number of scans before trigger event
postTrigScans u32 number of scans after trigger event
handle i16 handle