Use counter lines for DIO

[Simon_DK]

Hi

I am using PCIe-6612 and PCI-6601.

I use both counters and DIO simultaneously.

My question is if I can use counter lines (such as OUT and Gate) as DIO if they are not specifically used in the counter that is setup?

I use NI-DAQMX C called from a C# application.

Example A:

I use ctr0 for monitoring a linear encoder where the value is simply polled from the counter. Thus Gate (PFI 38) is not used and OUT (PFI 36) is not used and not configured.

Is there a way to release the unused lines so that they can be configured as digital output/input lines, while the counter is running?

The counter is setup with DAQmxCreateCILinEncoderChan

Example B:

Here the counter is used as a pulse generator and thus only OUT is used. The remaining 3 PFI channels are not used and should therefore be useable for DIO - but they are not accessible while the counter task is running.

This counter is setup with DAQmxCreateCOPulseChanFreq + DAQmxCfgImplicitTiming

[Kevin_Price · Accepted solution]

I would not expect you to have this problem.  I'm solely a LabVIEW guy and don't personally know the C syntax for DAQmx, but I did use the similar PCI-6602 device quite a bit in years past.  My recollection is that it was quite flexible in accomodating such signal routing, even allowing the same terminal to be used in both a counter task AND a DIO task, provided at least one of the tasks used it as an input signal.

Have you tried configuring and starting the DI/DO tasks *before* configuring the counter tasks?  Are you sure the DI/DO tasks only configure individual lines and aren't trying to configure the entire port?

Please post the code related to setting up and starting your DAQmx tasks -- that will improve the odds of getting relevant help.  Also let us know the exact error you get and where it occurs.

-Kevin P

[Simon_DK]

Hi Kevin

Thanks for your reply!

I have looked closer into this and it does seem like all the lines not specifically configured for a counter are free to use for DIO.

My problem was that I set up a digital output line and later configuring a CO task that by default used the same pin as a DO task.

This was easily solved by changing the CO "out" to a different line.