Using the NI 5650/5651/5652 REF IN/OUT Connector

The NI 5650/5651/5652 REF IN/OUT connector can be programmed as an input connector or output connector. Phase-locking to an external source configures the connector as an input connector, and exporting the reference signal configures the connector as an output connector. The ability to export or import the reference signal makes it possible to frequency-lock NI RF devices together using one as the master.

Note  Although the devices may be frequency-locked together, their generated RF signals are not phase-synchronized.

Coupling of the external reference signal into the reference circuit is possible, potentially producing offset phase spurs in the RF signal. For these reasons, disconnect or turn off any signals connected to the REF IN/OUT connector when REF IN/OUT is not being used.

Refer to the specifications document that shipped with your RF signal generator for NI 5650/5651/5652 onboard frequency reference specifications.