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Configuring Triggers

An analog input trigger is defined as the event that initiates data logging. Data can be logged to memory and/or a disk file. As shown in the figure below, when a trigger occurs, the Logging property is automatically set On and data is stored in the engine and/or a disk file.


When defining a trigger, you must specify the trigger type. Additionally, you may specify:

Properties that allow you to configure a trigger are shown below.

Table 4-5: Analog Input Trigger Properties
Property
 Description
TriggerChannel

 Array of channels serving as trigger sources
TriggerCondition

 Condition that must be satisfied for a trigger to be issued (depends on TriggerType)
TriggerConditionValue

 Trigger condition value
TriggerDelay

 Delay for trigger. A negative delay defines a pretrigger while a positive delay defines a
postrigger
TriggerDelayUnits

 Determines how a trigger delay is measured (time or samples)
TriggerAction

 M-file that is executed after the trigger is issued
TriggerRepeat

 Number of times to repeat the trigger
TriggerTime

 Array of observed absolute trigger times
TriggerType

 Source of the trigger

Additionally, the SamplesPerTrigger property specifies the number of samples to acquire per trigger for each channel group member.

Except for TriggerAction, these trigger-related properties are discussed in the following sections. TriggerAction is discussed in "Configuring Events and Actions".


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