The NI 5771 clock source controls the sample rate and other timing functions on the device. The following table contains information about the possible NI 5771 clock sources.
Table 1. NI 5771 Clock Source
|Internal Clock Locked to Internal Reference
||The internal reference is free-running.
|Internal Clock PLL On (IoModSyncClock)
||The internal reference locks to PXI_CLK10 through IoModSyncClock, which is provided only through the backplane of NI PXIe-796x devices.
|Internal Clock PLL On (REF IN)
||The internal reference locks to an external Reference Clock (10 MHz), which is provided through the REF IN front panel connector.
|External Clock (CLK IN) 
||850 MHz to 1.5 GHz
||An external Sample Clock can be provided through the CLK IN front panel connector.