Multiple channels on PCIe-6320 using C API

[_patrick_]

I am using a PCIe-6320 DAQ with the C API on Windows 7.

I need to generate a regular pulse output on myDAQ/ctr0 and then at random intervals read the DI ports myDAQ/port0:2.

As I understand it I can only run a single task on this card, so I have been trying to create multiple channels on the same task. However I am getting DAQmxErrorMultiChanTypesInTask. In pseudo code I call

CreateTask()

DAQmxCreateCOPulseChanTime("Daq1/ctr0")

DAQmxCreateDIChan("Daq1/port0:2")          <-- this gives DAQmxErrorMultiChanTypesInTask

What am I doing wrong? Is there a better way to accomplish this?

Any and all advice gratefully received.

Thanks

Patrick

[Kevin_Price · Accepted solution]

You can run multiple tasks on that card.  The main real restriction is that you can have only 1 hardware-timed task running at a time for each of the following major subsystems: AI, AO, DI, DO.  But you can indeed have 1 each running simultaneously for a total of 4.  You can also have a number of software-timed "on-demand" type tasks for each subsystem.  And you can have several additional counter tasks as well.

So you just need 2 separate tasks, 1 for counter output and 1 for digital input.  Your DI task can probably be software-timed, given your comment about "random intervals." 

As a LabVIEW-only guy, I really can't help with any specific syntax though.

-Kevin P

[_patrick_]

Thanks very much for the reply. Following your suggestions I set the DI to on demand timing and everything seems to be doing what I want.

I also had to read the whole channel, myDAQ/port0, rather than the lines I originally wanted, myDAQ/port0:2, as the latter would not work. But all is looking good. Thanks again.

[Kevin_Price]

The syntax in LabVIEW for the lower 3 bits of port 0 would look like:

"MyDAQ/port0/line0:2"

-Kevin P