© National Instruments | 9-3M Series User ManualSynchronizing Multiple DevicesThe following sections contain information bout synchronizing multiple M Series devices.PXI/PXI Express ModulesOn PXI systems, you can synchronize devices to PXI_CLK10. In this application the PXIchassis acts as the initiator. Each PXI/PXI Express module routes PXI_CLK10 to its externalreference clock.Another option in PXI systems is to use PXI_STAR. The Star Trigger controller device acts asthe initiator and drives PXI_STAR with a clock signal. Each target device routes PXI_STAR toits external reference clock.PCI/PCI Express DevicesWith the RTSI and PFI bus and the routing capabilities of M Series PCI/PCI Express devices,there are several ways to synchronize multiple devices depending on your application.To synchronize multiple devices to a common timebase, choose one device—the initiator—togenerate the timebase. The initiator device routes its 10 MHz reference clock to one of theRTSI <0..7> or PFI <0..15> signals.All devices (including the initiator device) receive the 10 MHz reference clock from RTSI orPFI. This signal becomes the external reference clock. A PLL on each device generates theinternal timebases synchronous to the external reference clock.Once all of the devices are using or referencing a common timebase, you can synchronizeoperations across them by sending a common start trigger out across the RTSI or PFI bus andsetting their sample clock rates to the same value.USB DevicesWith the PFI bus and the routing capabilities of USB M Series devices, there are several waysto synchronize multiple devices depending on your application.To synchronize multiple devices to a common timebase, choose one device—the initiator—togenerate the timebase. The initiator device routes its 10 MHz reference clock to one of thePFI <0..15> signals.All devices (including the initiator device) receive the 10 MHz reference clock from PFI. Thissignal becomes the external reference clock. A PLL on each device generates the internaltimebases synchronous to the external reference clock.Once all of the devices are using or referencing a common timebase, you can synchronizeoperations across them by sending a common start trigger out across the PFI bus and setting theirsample clock rates to the same value.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
