Reserved DIO channels in PCI-6251M

[MI guy]

I have a vi simply reading DIO 0 line then set a flag, nothing fancy, using DAQmx Read, Digital Bool 1Line 1 Point. Running it alone, the vi works fine, when I intergrate this vi into a loop (250ms wait per loop iteration), I get a channel reserved error.

Any idea?

[Salvador_Santolucito]

Are you calling the start task in the loop? The only thing that should be in the loop is the read. The startTask should go before and the clearTask should go after the loop.

Check out the attatched example.

[MI guy]

Why can't I just use one DIO read with the channel name directly wired to the vi instead of building a task and start and stop ? It's only 1 channel 1 single read. I've done it in earlier Labview versions without any problem.

Anyway, I finally removed the DIO read from the loop and only call it when necessary to avoid the headache.

Thanks for your response.