Use external clock (PFI2) with Traditional DAQ

[zou]

Can figure out how to specify the external clock line (PFI2) while using Traditional DAQ (7.4.2f3).

Can anyone help?  TIA.

George

[RobertoBozzolo]

I never used such a configuration but I found an example that will probably be helpful for your problem: it's named SCANsingleBufExtScan and you will find it in samples\daq\ai folder on your hard disk.

[zou]

Thanks for reply.

In that example, it doesn't tell me how to use PFI2 pin as external clock.  It only tells me: "Also, connect a digital pulse train to the 'external scan clock' pin. (NOTE: This is NOT the pin labelled "SCANCLK" but instead is a counter output pin.)

A counter output pin?  What is the pin #?

[josswern]

I have a similar application where I use this:

    Select_Signal(Board, ND_IN_SCAN_START, ND_PFI_2, ND_LOW_TO_HIGH);

to specify PFI2 as external clock source.
to find the correct pin for PFI2, refer to the manual of your DAQ device.

[Sergio_R]

This helped me determine which pin to use for my external clock signal to trigger from PFI2:

http://digital.ni.com/public.nsf/websearch/39F8242E2553F63E86256FE3007BF69F?OpenDocument