Parallel testing with usb

[Schwede]

Hello,

i want to make a parallel testing of two testsockets. Each socket have one usb-6009 device and different daq-mx tasks and scalings for data acquisition. I have written a customer step (with LV) to get the data (test runs 80sec). When I start test 1 it starts but if i want then (a bit later) to start test 2 it starts not until test 1 ends. I'am using TS3.0, LV8.0 and parallel model.

Have anybody a solution? Is this a usb port problem?

thankyou

schwede

[Norbert_B]

Schwede,

since you created one step for the test, i asume both sockets use the same module. So it's natural that you can only execute the step from one socket at a time.
The solution would be either changing the module to reentrant or to create single modules for each socket.

Norbert B.
NI Germany

[Schwede]

I have tried both. And it is the same. TestStand executes only one step at a time.

Schwede

[James_Grey]

I'm not a LV expert, but I think only one instance of a VI can run at a time unless you mark the VI as reentrant. So, you could make copies of your VI, or mark it as reentrant. I know that some (or all?) versions of LV can't debug reentrant VIs, so you might want to wait until the VI is debugged to do that.

(If LabVIEW now supports reentrant debugging, maybe somebody can mention the LV version number in which that feature was introduced?)

[Schwede]

Hello,

that is right, but I have tried to use two different vi`s with the same result. I think something is with the usb configuration (MAX?).+

[James_Grey]

If you have two VIs and you are definitely getting into both at the same time, but one is blocking the other, then you will have to debug them and see which node is blocking and see what the other vi doing while the node is blocked.

[Dennis_Knutson]

I know for a fact that you can have several VIs in parallel that communicate over USB. I'm using some custom instruments and not the USB-6009 but that shouldn't make any difference. Are you using the DAQ Assistant or the lower level DAQmx functions? If your are using the DAQ Assistant, convert that to a normal subVI and you make the subVIs re-entrant.

[paulmw]

If your two seperate VI's call a common sub VI, and that VI is not re-enterant, only one will execute at a time too.

I had this situation with the parallel process model using RS232 serial.  The serial port number to use was dependant on the test socket index.  I had a sub VI inside the VI module that I called that wasn't re-enterant and took some execution time to complete.  I spent some time thinking that is was serial resources (VISA) not running in parallel when all along it was some other post processing that could also run re-entrant.

Paul