Analog Input Range Values on TEDS Devices

Updated May 1, 2018

Reported In

Hardware

  • PXIe-4499

Driver

  • NI-DAQmx

Issue Details

I am expecting the NI-DAQmx drivers to read the maximum and minimum range values from the TEDS information when using a TEDS sensor with a TEDS compatible device. The default readings for my NI MAX task don't match  the maximum and minimum values from my TEDS sensor information. Why does this happen?

Solution

The NI-DAQmx drivers do not use the Analog Input range values if they are stored to the TEDS device. The user is still expected to set those values. The default values will be at +5 and -5 V times the sensitivity of your sensor.

For example, the range on an Analog Input task for an accelerometer with a sensitivity of 0.522938 Volts/g will default to +/- 95.6136 g.



DAQmx will throw an error if the selected g value corresponds with a voltage that is outside range of the device. In this example, using the same accelerometer with 0.522938 Volts/g sensitivity on a PXIe-4499 with a range of +/- 10 V, the maximum range for an Analog Input task is +/- 191.22722 g. Trying to set a value greater than that will result in a DAQmx error.

Error -200077 occurred at DAQ Assistant

Possible Reason(s):
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.



 

Additional Information

This is to support the case of a user using a sensor in a smaller range than the sensor can actually support: the user may only care about a certain temperature range for example, which limits the output of the sensor to a certain voltage range. Choosing the appropriate device range allows the user to maximize accuracy/resolution.

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