|NI-SCOPE 18.7 (English | Japanese)|
A trigger is an external stimulus that initiates one or more instrument functions. Trigger stimuli include digital edges, software functions, and analog levels. The trigger can be derived from attributes of the signal to be acquired, such as the level and slope of the signal.
You can use several types of triggering with NI high-speed digitizers, including immediate, software, hysteresis, edge, window, digital, and video triggering. Each kind of triggering uses a different NI-SCOPE Configure Trigger function.
The following table describes the triggers supported by NI high-speed digitizers. The Supported Types column denotes which trigger types are valid for a given trigger.
|Trigger Name||Supported Types||Description|
|Start||Digital Edge||The Start trigger transitions a device into a state where the device can respond to Sample clocks. This trigger transitions the device from a nonsampling state into a sampling state—the device starts acquiring and storing data.|
|Reference||Analog, Digital, Video||The Reference trigger transitions a device from the Wait for Reference Trigger sampling state into the Post Reference trigger sampling state. In the Post Reference Trigger sampling state, a counter begins counting Sample clock cycles. When the configured number of samples is acquired, the device transitions into a Done state. In other words, the arrival of this trigger establishes the reference point that separates pretrigger and posttrigger samples.|
|Advance||Digital Edge||The Advance trigger initiates the acquisition of the additional
records in a multirecord acquisition.
|Arm Reference||Digital Edge|| The digitizer acquires pre-reference triggers until the Arm Reference trigger is received. For more information, refer to
SMC-Based Digitizers Acquisition Engine State Diagram.