Changing range voltage for NI acquisition : how to solve : Warning: Cannot support range of -5.0 to +5.0 Volts. Range set to -10 to +10 Voltt ?

i try to change voltage range for NI card acquisition. If i use Daq Express or labview it works but from matlab i can't.

The code :

clear

close

clc

% %% acquisition

dq = daqlist("ni")

deviceInfo = dq{1, "DeviceInfo"}

%%

dq = daq("ni")

dq.Rate = 2000;

ai2 = addinput(dq, "Dev5", "ai2", "Voltage");

ai2.Range = [-5 5];

ai2.TerminalConfig = "SingleEnded"

Et voici l'erreur :

Warning: Cannot support range of -5.0 to +5.0 Volts. Range set to -10 to +10 Volts.

Answer 1

[Mario Malic]

Hello!

It's just a warning, it will work, range is still in between -10V and 10V. Why wouldn't you utilize the full range of your acquisition channel? For example, if you have a sensor with specific sensitivity that will produce Voltage signal that is above 5V or below -5V, you wouldn't measure signal correctly as it would be overloaded.

Also, this is a property of an acquisition card, some cards (maybe none?) do not support adjusting the range.

It might be of help, still in a development stage. I made this to acquire data from NI devices easily. Hopefully it works on R2021b. https://uk.mathworks.com/matlabcentral/fileexchange/128118-daqx

[Pi_etudiant]

Hello !

I don't use the whole range because the values of my machine are written in the properties as +5V and -5V.

However as you say it's just a warning but when I look at my properties nothing changes and the terminals remain -10 +10V.

Do you have another solution?

Thanks for your answer!

[Mario Malic]

It is not neccessary to change the range. This Range property is related to the acquisition device, not the sensor.

Your measurement device will output the 5V signal and it is not going to cause any issue with the measurement.

[Pi_etudiant]

ok, thank you !

Answer 2

[Hassaan]

1. Driver Limitations: The MATLAB Data Acquisition Toolbox may not fully support all features of the NI hardware driver that are available in LabVIEW or NI-DAQmx.
2. Hardware Constraints: The NI card itself may have limitations on the supported ranges based on the mode you're using (for example, SingleEnded vs. Differential).
3. Software Configuration: The configuration of the NI card through MATLAB might have constraints that differ from the configuration through LabVIEW or NI-DAQmx.

Here are some steps to troubleshoot:

• Check Compatibility: Ensure that your version of MATLAB, the Data Acquisition Toolbox, and the NI driver are all compatible and up-to-date.
• Consult Documentation: Refer to the documentation for both your NI card and the MATLAB Data Acquisition Toolbox to confirm the supported voltage ranges.
• Test Range Support: Try testing different supported ranges programmatically to see if any others are accepted. Sometimes, NI cards support a limited set of ranges in certain configurations.
• Device Configuration: Check if the device needs to be configured differently in MATLAB compared to LabVIEW or NI-DAQmx.
• Software Reset: Sometimes resetting the device configuration through the NI Measurement & Automation Explorer (MAX) can resolve software conflicts.
• Contact Support: If you continue to experience difficulties, consider reaching out to MathWorks Support for assistance specific to the Data Acquisition Toolbox.

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