Range vs limits in RSE or DIFF mode

[ttzvetkov]

Hi ,

I have the following question.

Some multifunction DAQ boards like 6009 support multiple ranges only for Differential analog input configuration like ±20V, ±10V, ±4V, ±2.5V, ±2V, ±1.25V, ±1V, while RSE mode supports only ±10V . However the device property node lists all the ranges available. When configuring the analog channel there is an option to select the signal limits and based on the limits the DAQ driver automatically selects the range.

My problem is how to detect, based on the mode I select (DIFF vs RSE ), what ranges are available to allow the user to select the proper voltage range without deceiving the user to think that higher accuracy is selected but the board is using only ±10V without regard of what limits are selected. 

For example if the device is configured to use AI in DIFF mode selecting signal limits ±1V will lead to measurement in ±1V range (higher precision), but if the device is configured to use RSE mode selecting ±1V limits will mean nothing, because the driver will still use ±10V range because only that range is available. 

Thank you,

Ted

[SnowMule]

Don't think there's anything coded in DAQmx that forces that on a device-specific basis... you'd more than likely have to build that functionality into your code.

IF device=600x AND mode=RSE THEN range=10v,
IF device=600x AND mode=DIFF THEN range=20,10,4,2.5,1 etc.

[ttzvetkov · Accepted solution]

HI,

Thank you for the response. The solution you suggested works if the info for 600x series or if there is a list of DAQ cards coded in the software. However I have played a little bit and found a more elegant and DAQ independent solution. Here is the diagram.

Bellow is the example VI. The output array actually will have duplicates of range for ranges that are used instead of unavailable ranges, but then the removal of the duplicates is trivial.

Ted