timebase and reference clock

[hilary]

What is timebase and reference clock mean inside DAQmx Timing Properties?

How could I generate 80M Hz clock to be synchronized as the backplane clock for all the PXI devices?

Thanks!

[Brian F.]

Hello Hilary.  The PXI backplane actually has a 10 MHz PXI Clock built into it.  The 80 MHz internal timebase of many of our DAQ cards is too fast to pass through the backplane/ RTSI bus.  There is a great knowledge base article that explains this in great detail at:

Multi-Device Synchronization

http://zone.ni.com/devzone/cda/tut/p/id/3615#toc4

The examples embedded in this article use the DAQmx timing property nodes as well so this should be a great resource for you!  Finally, at the very bottom of this page, there is a zip file available for download that contains numerous examples (both PCI and PXI) that deal with multi-device synchronization.  Please explore these to get an idea of what is required to programmatically implement this synchronization.  I hope this resource is as valuable to you as it is to me.  Let me know if you have any questions about it and I will be happy to address them.  Have a great day!

Brian F

Applications Engineer

National Instruments