NI PXI-5404
REF IN Connector
The REF IN connector is a PLL input connector that can accept a Reference clock from an external source and frequency lock the NI 5404 internal clock to this external clock. The Reference clock can be 3 MHz to 20 MHz in 1 MHz steps. The clock should not deviate more than ±50 ppm from its nominal frequency. You can use a sine wave or a square wave from 250 mVpk-pk to 5 Vpk-pk as the Reference clock.
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Note You can frequency lock the NI 5404 to other NI devices using the 10 MHz backplane clock. |
If an external Reference clock is not available, the NI 5404 automatically tunes the internal clock to the highest accuracy possible.