TriggerFcn (Data Acquisition Toolbox)

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

Description

A trigger event is generated immediately after a trigger occurs. This event executes the callback function specified for TriggerFcn. Under most circumstances, the callback 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).

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

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