Are there issues with running two LabVIEW applications (built .exes) at the same time ?

[davey31415]

If I compile two different LabVIEW applications and connect two USB DAQ devices, is it possible to run both applications that the same?

Thanks,

Dave

[smercurio_fc · Accepted solution]

If each application is talking to a separate device then there should be no issues as far as I know. If the two applications are trying to talk to the same device then you need to be aware that you can only execute one task at a time on a device.

[Matthew_Kelton]

You also  need to make sure you have enough CPU resources and USB bandwidth to handle the two applications running concurrently.

[hecmar.arreola]

If you plan on connecting to the VIs on another computer via Remote Panels, I've found that you can only connect to the first one that was launched.  There is probably a work around for this issue, however.

[davey31415]

Thanks all.  Useful information. 

When working in an application to begin with, is the"one task per DAQ device" still requirement still valid? 

I was running a VI several months ago which was leaking memory because a new task was being created over and over but did not know more than one task caused a problem in general.  I thought the problem resulted from thousands of tasks being created without being closed. 

[RavensFan]

No, the issue is that only one task can have access to certain hardware resources at a time.  Think of trying to open an Excel file on the network while another person tries to open the same file.  Same sort of situation.

[Dennis_Knutson]

When working with any DAQmx device in any environment (built application , development, LabWindows/CVI, VB, .Net, etc), you can only have one task for a specific hardware resource (analog input/analog output) with the majority of DAQ boards.

[davey31415]

Okay.  One device may have several resources though?  (analog input, analog output, digital input, digital output would all be separate?) 

[RavensFan]

Maybe. But it depends on the type of acquisition you are doing.  If they were all doing a timed acquisition (as opposed to a 1 sample acquisition), you'd have a problem because each task would require a hardware clock which is a resource, but there is only one hardware clock on the DAQ board.

[smercurio_fc]

Rather than guessing, why don't you tell us what the DAQ devices are, what you want to be running on the devices, and what each LabVIEW program is supposed to do, and then we can tell you whether it's possible.