NI 5402/5406
REF IN Connector

The REF IN front panel connector can accept an external Reference clock

Caution  You must not change the Reference clock frequency while waveform generation is in progress. Only modify the frequency of the external clock before you start the waveform generation or after you stop the waveform generation.

External Reference Clock Input

The REF IN connector is an input that can accept a Reference clock from an external source and phase lock the internal clock of the signal generator to this external Reference clock. Refer to the module specifications for the allowable Reference clock frequencies and signal characteristics.

The default value for the Reference clock source is Internal. Refer to the niFgen Configure Reference Clock VI or the niFgen_ConfigureReferenceClock function for more information about configuring the Reference clock source and frequency.

Note  You can also phase lock the signal generator to other NI devices using the common PXI 10 MHz backplane clock for PXI or the RTSI 7 line for PCI. Refer to PLL Reference Sources for more information.