Start Trigger Signal

Use the Start Trigger (StartTrigger) signal to initiate a waveform generation. If you do not use triggers, you can begin a generation with a software command. If you are using an internal sample clock, you can specify a delay from the start trigger to the first sample. For more information, refer to the NI-DAQmx Help.

The name of terminal using the Start Trigger task can be queried using the Start Trigger Terminal Property.

Using a Digital Source

To use Start Trigger, specify a source and a rising or falling edge. The source can be one of the following signals:

  • A pulse initiated by host software
  • Any PFI terminal
  • AI Reference Trigger/DI Reference Trigger
  • AI Start Trigger/DI Start Trigger

The source also can be one of several internal signals on the TestScale backplane. Refer to the Device Routing in MAX topic in the NI-DAQmx Help or the LabVIEW Help for more information.

You also can specify whether the waveform generation begins on the rising edge or falling edge of Start Trigger.

Using an Analog Source

Some TestScale modules can generate a trigger based on an analog signal. In NI-DAQmx, this is called the Analog Comparison Event, depending on the trigger properties.

When you use an analog trigger source, the waveform generation begins on the first rising or falling edge of the Analog Comparison Event signal, depending on the trigger properties. The analog trigger circuit must be configured by a simultaneously running analog input task.

Note Depending on the TestScale module capabilities, you may need two modules to utilize analog triggering.

Routing Start Trigger Signal to an Output Terminal

You can route Start Trigger to any output PFI terminal. The output is an active high pulse.