NI-DCPower supports the following synchronization methods.

Software-Based Synchronization—Sends a software command from a host computer to an instrument. Not deterministic on general-purpose operating systems such as Windows.

Accuracy: tens of milliseconds

Time-Based Synchronization—Uses a time-based protocol such as GPS, 1588, or IRIG-B to coordinate events. Can be used over large distances (>10 m). Remote chassis that include a PXI synchronization module can be programmed to generate triggers on the backplane at a specific time.

Accuracy: <100 ns + NI-DCPower instrument trigger delay and jitter

Signal-Based Synchronization—Uses trigger signals to coordinate operations. Comprises the following:

• PXI Trigger Routing—Sends a trigger signal, which corresponds to an event, from one instrument to another through the routes available in a PXI chassis (for PXIe/PXI instruments). The closer the signal paths between instruments are in length, the better the synchronization accuracy.

  Accuracy: tens of nanoseconds + NI-DCPower instrument trigger delay and jitter

• External Triggering—Sends a signal external to a PXI chassis or, for other instrument form factors, to an instrument through I/O lines. The closer the signal paths between instruments are in length, the better the synchronization accuracy. Time locking improves determinism.
  Note Most NI-DCPower instruments cannot receive external digital triggers via their front panels. However, for NI-DCPower instruments that support triggering, you can send an external trigger to the instrument through another instrument installed in your chassis that does accept external triggers. You can route these trigger signals through the trigger lines on the chassis backplane.

Refer to the PXIe-4138 Specifications for the trigger delay and jitter of your instrument.