User manual

Chapter 3 Software Overview
© National Instruments Corporation 3-11 NI-DAQ User Manual for PC Compatibles
The
AnalogTriggerEventn_Fire
procedure is prototyped as follows:
Sub AnalogTriggerEventn_Fire
(DoneFlag As Integer,
ScansAsLong)
The parameter DoneFlag equals 1 if the acquisition was over when the
Analog Trigger Event fired. Otherwise, it is 0. Scans equals the number of
the scan that caused the Analog Trigger Event to fire.
Analog Alarm Event
Use the Analog Alarm Event control to configure and enable an analog
trigger. See the Event Message Functions section earlier in this chapter for
a definition of the analog trigger.
Table 3-3 lists the properties for the Analog Alarm Event control.
The Analog Alarm Event requires that you set the asynchronous
data acquisition operation to use interrupts. For more information
on Analog Alarm Events, refer to the description for the
Config_Alarm_Deadband
function in the NI-DAQ Function
Reference Online Help file.
Table 3-3. Analog Alarm Event Control Properties
Property Allowed Property Values
Name
GeneralDAQEventn (default)
Board
1–n (default)
ChanStr
See
Config_DAQ_Event_Message
in the
NI-DAQ Function Reference Online Help
file
HighAlarmLevel
Single (voltage)
LowAlarmLevel
Single (voltage)
HighDeadbandWidth
Single (voltage)
LowDeadbandWidth
Single (voltage)
Index
N/A
Tag
N/A
Enabled
0—False (default)
1—True