Chapter2 HardwareOverview
NI5620 User Manual 2-8 ni.com
Synchronizing Multiple PXI Devices
The NI 5620 uses a PLL to synchronize the 64 MHz sample clock to a
10 MHz reference clock. You can either supply the reference clock through
the SMA connector (REF CLK IN) on the front panel or use the system
reference clockon the PXI backplane.
The PXI busand the NI 5620 have the following timing and triggering
features that you can use for synchronizing multiple digitizers:
•SystemReference Clock—Thisisa10MHzclockonthePXI
backplane with ±100 ppm accuracy.It is independently distributed to
each PXI peripheral slotthrough equal-length traces with a skew of
lessthan 1 ns between slots. Multiple devices can use this common
timebasefor synchronization. This allows each NI 5620 to phase lock
to the system reference clock.
•SMA connector (REF CLK IN)—This is a 10 MHz reference input
that you can use to connect your external frequencysource for
synchronization.