07-26-2010 09:33 AM
Hi,
i have a 9174 cDAQ with a 9215 analog module and a 9401 module. I wonder if this configuration is suitable for my purpose : a extern digital trigger is sent to the system to trigger a analog input task, trigger a pulse generation, with another counter counting trigger events. Using two counters on 9401, it seems i have no terminal left to input my trigger signal. The DAQmx trigger vi doesn't show the counters inputs in the signal list ; and if i select a PFI line, an error says that the line is already in use...Do i have missed some obvious solution ? Do have i to change my 9401 to a 9402 ?
Thanks for any help,
Vincent
Solved! Go to Solution.
07-26-2010 01:40 PM
Hi Vincent,
So it sounds like you need a single line to be used as an input for trigger events, and another line to be used to output a pulse generation. This should indeed be possible, since the 9401 has 8 lines that are nibble configurable (i.e. lines 0:3 could be configured as inputs, while lines 4:7 could be outputs, or vice-versa).
However, one big caveat with the 9401 is that the lines should be reserved before either task is started. This is a limitation of how the line direction is implemented in hardware, and is a common issue that customers run into when using the 9401. Explicitly reserving your tasks before starting should fix the behavior if this is indeed what you are seeing.
Best Regards,
07-27-2010 07:57 AM
Thanks John,
i didn't know about the reserve function...and i don't get the error anymore !
Vincent