Parallel Measurements from NI455X DSA boards

[GeekGrok]

Hello,

    I am trying to find out if I can use the TestStand Batch (or Parallel) model to read multiple channels from a DSA NI455X board? My hope is that I can read each channel from a seperate thread. Are there any example sequences for doing this?

    Thank you in advance for all of your help!

Happy Holidays,

Jim

[Caroline Bright]

Hi Jim,

The DSA 455x boards use the Traditional DAQ driver which does not support multithreading.  If you were to try and acquire from one channel and then use another thread in TestStand, using the parallel or batch model, to acquire from another channel, you would be "blocked" from acquiring in this second thread, so you would be unable to acquire from multiple channels in parallel using TestStand.  You could however, have one thread acquire and once it is finished then execute the acquire step from another thread.  You would just need to lock the steps in each thread to wait until the previous acquire was finished.  Unfortuantely this would not allow for parallel acquisition.

[GeekGrok]

Hi Caroline,

    Thank you for your response. I have a quick follow up question.

     As you know, the 455x series of boards are being discontinued by NI. Because of this, I am looking at going to a newer (i.e. PXI based) DSA board. Would these newer boards (i.e. PXI-4461 and PXI-4462) support multi-threading?

     Thank you again for your time and effort.

Thanx,

Jim

[Travis_W]

Jim,

This is Travis over at NI.

Although the 4461 and 4462 DSA boards are supported in DAQmx, this will not allow you to read your different channels with different threads.  Due to a hardware limitation of these boards (as well as the 455X boards), you will receive a "resource is reserved" conflict if you try to use two DAQmx tasks on same device.

You can, however, use multithreading in other ways to increase the performance of your system.  For instance, you could acquire you data in one thread, process it in another, and present it in a third.

Thanks, Jim.  Have a great day!

Regards,
Travis