NI PXI/PCI-5401/5411/5431
Trigger Sources

Trigger sources are software selectable. By default, the device starts immediately unless a Start trigger is selected. You can also use an external trigger from a pin on the digital I/O connector, the RTSI bus trigger lines for PCI devices, or the PXI trigger bus TTL trigger lines on the backplane for PXI devices. The following figure shows the trigger sources for NI signal generators.

If you need to automatically trigger the waveform generation, use software to generate the triggers. You need a rising TTL edge for external triggering.

For external triggering, apply a rising-edge TTL signal to the EXT_TRIG input. This signal should remain de-asserted (logic low) until after the software has initialized the waveform generation.