How to use DAQmxCfgSampClkTiming(...) on PXI-6259

[Roy_]

I am attempting to send a short serial message using a buffer for Digitial Out and need a clock reference (up to 2MHz).

When I set up using DAQmxCfgSampClkTiming ( taskhandle, source as String, rate, active edge, sample mode, samples per channel)

then follow with DAQmxWriteDigitalLines (same taskhandle, buffer size, autoStart=False, timeout, data layout, write array, samples per channel written)

I get an error message stating that the source is invalid. I have tried every source I can think of but believe "PFI12" is the appropiate one.

Can someone tell me how to set up the source properly?

[kikiduu]

Just to verify, while specifying the sample clock source you used the string "DevName/PFI12" instead of just "PFI12", isn't it?

[Jordan F]

Hi

One of the C examples included with the DAQmx driver shows that you should use /"Device name"/PFIx (for example /Dev1/PFI0) if you wish to use an external clock with your digital output. 

The Daqmx C examples can be found under Start>>Programs>>National Instruments>>NI-DAQ>>Text Based Code Support.  They have some different examples on how to set up a correlated digital output task. 

Message Edited by Jordan F on 03-22-2009 10:38 AM