Use DAQ in Parallel Mode

[mfitzsimons]

Is there any issues using a DAC card (M-Series) in TestStand in Parallel Mode?  I would like to have 4 instances running in parallel all using ine DAC card.  Of course, each instance would be using separate channels.  How would you create the reference to the DAC card?  I assumed that one insides could open the DACCA card but could be a race conditon.

[AllenP]

The M series cards (if I remember correctly) only have one clock for input and one for output.  This means that you can only do one operation at a time on the device, even if it has multiple channels.  If you are doing a true parallel test (rather than a batch test), I would recommend using a Lock in TestStand on the card so that only one UUT tries to access the device at a time.  If you are using Batch, you can use the same setup, or have a "worker" thread that does the DAQ operations and then sends the data to each thread using a Notifier.  Depending on how long you are using the card, this may be more trouble than just doing it independently and using locks.

Allen P.
NI