Data Acquisition Toolbox    
TriggerAction

Specify the M-file action function to execute when a trigger occurs

Description

A trigger event is generated immediately after a trigger occurs. This event executes the action function specified for TriggerAction. Under most circumstances, the action function is not guaranteed to complete execution until sometime after Logging is set to On for analog input (AI) objects, or Sending is set to On for analog output (AO) objects.

Trigger event information is stored in the Type and Data fields of the EventLog property. The Type field value is Trigger. The Data field values are given below.

Data Field Value
Description
AbsTime
The absolute time (as a clock vector) the event occurred.
RelSample
The acquired (AI) or output (AO) sample number when the event occurred.
Channel
The index number for each input channel serving as a trigger source (AI only).
Trigger
The trigger number (AI only).

Characteristics

Usage
AI, AO, Common
Access
Read/write
Data type
String
Read-only when running
No

Values

The default value is an empty string.

See Also

Functions

trigger

Properties

EventLog, Logging


 TimerPeriod TriggerChannel