TriggerFcn

Specify callback function to execute when 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.

Characteristics

Usage

AI, AO, common to all channels

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

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