Setting NI-DAQmx Channel Gain by Min/Max Value or Range High/Low in LabVIEW

Updated Oct 24, 2020

Environment

Software

  • LabVIEW Full
  • LabVIEW Base
  • LabVIEW Professional

Driver

  • NI-DAQmx

At present, I set the NI-DAQmx device channel gain by changing the range. I want to know whether I should use the properties of Maximum/Minimum Value or Range High/Low. What is the difference between these two?

You can configure your own device channel gain by two ways as follows.
  1. Setting it by Maximum/Minimum Value
There are also two ways by Max/Min Value:
  1. By DAQmx Create Channel VI, you can set it by Max/Min Terminal as Figure 1 shows.
  1. By selecting Maximum/Minimum Value Properties
Select DAQmx Channel>>Analog Input>>Maximum/Minimum Value, like on Figure 2.
  1. Setting it by Range High/Low Properties
Select DAQmx Channel>>Analog Input>>General>>Advanced>>Range>>High/Low, as shown on Figure 3 below.

The main difference between the two methods is the units to which they refer.
  • The Max/Min value matches the appropriate units for the type of signal created by the DAQmx task. For example, Max/Min will refer to degrees of Celsius when doing an analog thermocouple input task, but it refers to amps for an analog current input task.
  • When setting the range using high/low, the units are reflected in the DAQ device's native units. For example, the range for a DAQmx task using an E series device will be in volts.
 

Additional Information

You should avoid using both methods for the same task. If you set both Max/Min and High/Low, NI-DAQmx uses the last value to determine the channel gain.