Importing MAX Input Voltage Configuration into LABVIEW

[shawesome]

I recently had a customer create a global virtual channel in Measurement and Automation Explorer (MAX).  They then set the maximum and minimum values for the input range of their signal. 

My customer wanted to access the +2 and -2 values entered above and display them in LabVIEW.  However, the property nodes for global virtual channels only accesses the limits of the board.  For example, the customer's board may only be able to handle voltages between +/- 10 Volts.  No matter which property node we chose... all that was returned was the +/- 10 Volt range.  Could we please give customers access to this information?

[Dennis_Knutson]

This should probably be a suggestion to the DAQ Idea Exchange as it would require a new property. However, what kind of useful information would be returned? The +/- 10 is the actual range. The +/-2 are not the limits that are actually used.

[Seth_B.]

Which device was used?  If the device only has a ±10V range, even if you set the +2 and -2 in the Global Virtual Channel, the hardware will be set to ±10V and will return data beyond ±2V.  Setting +2 and -2 will have no effect unless there is a smaller voltage range that the DAQ device can use.

[Brad_K]

To state this more generally: when DAQmx coerces properties based on the device's capabilities, you want to be able to read the original value that the user set, not just the value that DAQmx coerced it to. Is that correct?

If that's the case, then there's no technical barrier to implementing this idea. DAQmx saves the user's desired value for every property (not just those that are used by the DAQ Assistant), but these are not currently readable through the API.

[Dennis_Knutson]

But of what possible use is the original value? I think you would need to provide a use case.

[Brad_K]

One use case that springs to mind: display the original value like the DAQ Assistant does.

Also, there is a potential workaround: export the MAX configuration to an INI file and read it using the configuration file VIs. However, being able to read the original values directly would be much more straightforward.