External Timebase using DAQmx and LabVIEW

[willsyale]

Hi,

I have a really simple question but I can't seem to find the right documentation to answer it.

How do use an external reference source for the timebase of my dac for analog signal acquisition?  I'm using a PCI-6251, LabView 7.1 and DAQmx.  Also, I have a BNC-2090 which has bnc connectors for APFI0 and PFI0.  Do I need to route one of these to a terminal within my dac? (how do I do this?)  Or is there a simple DAQmx vi that I have missed?  I am familiar with using DAQmx with LabVIEW and have written several vis but I have never routed any terminals or used an external reference.

Thanks
Will S

[willsyale]

Also, I don't know if this makes a difference, but I'd like to use an analog 10MHz 3V pk-to-pk signal for the reference if possible.

[tnek]

Hi Will,

You can import an external timebase by using the Timing property node in LabVIEW. You can set this external clock to be your sample clock timebase. These properties can be found in the Timing property node under Sample Clock » Timebase » Rate/Source.  Make sure you specify the rate along with your source. Another thing to check is your incoming signal. Ensure that it is a TTL compatible signal.

Regards,
Kent
Applications Engineer