Справочник Пользователя для National Instruments Welding System 321645c-01
Chapter 2
Function Reference — Config_DAQ_Event_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)
preTrigScans, postTrigScans, handle, message,
callbackAddr)
Purpose
Notifies NI-DAQ applications when the status of an asynchronous DAQ operation (initiated
by a call to
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.
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.
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