NI-DAQmx Device Properties Return Incorrect Values on FieldDAQ

Updated Feb 12, 2020

Reported In

Hardware

  • FD-11609
  • FD-11614
  • FD-11605
  • FD-11601
  • FD-11603
  • FD-11634
  • FD-11613

Driver

  • NI-DAQmx

Issue Details

I am trying to query the maximum and minimum sample rates for my FieldDAQ devices but the properties I am using appear to be returning the wrong values. I am using the properties below, but I do not see values returned that seem to match what I see in the User Manual for my device. Why is that? 
  • AI.MaxSingleChanRate
  • AI.MaxMultiChanRate
  • AI.MinRate

Solution

When using NI-DAQmx Device properties you must specify the Active Device to get/set the property for that particular device. For FieldDAQ devices you can either choose the FieldDAQ itself or one of the Banks on the FieldDAQ. If you select the FieldDAQ itself the values returned will not apply to your specific model of FieldDAQ. If you want the properties to return values specific to your model of FieldDAQ you need to specify the Active Device as the bank on the FieldDAQ. 

Example:
If using an FD-11601 and querying AI.MaxSingleChanRate you will see the following.

Active Device: FieldDAQ 



Active Device: FieldDAQ Bank



This same principle applies for AI.MaxMultiChanRate and AI.MinRate.