Why do I get a device is not registered error in MATLAB when I try to create a NI-DAQ object?

First, I open the Measurement and Automation utility for NI-DAQ version 6.7. Then, I open MATLAB and try to create a NI-DAQ object using ANALOGINPUT. I get the following error:

 the device is not registered

Even if I close MATLAB and restart it again I am not able to create any NI-DAQ objects.

Answer 1

[MathWorks Support Team]

This problem is associated with all versions of the Measurement and Automation utility for NI-DAQ before version 6.8. In order to create NI-DAQ objects in MATLAB you must reboot the computer.

We recommend using version 6.9 of the Measurement and Automation utility for NI-DAQ. However, please note that you may still come across the following situations:

1. If you have the Measurement and Automation utility open you cannot access NI-DAQ objects in MATLAB. Closing the utility will let you access NI-DAQ objects.

2. If you are in MATLAB and you open a NI-DAQ object you cannot use the Measurement and Automation utility. Even if you close or delete your object you will still not be able to access the utility. The utility will be available after closing MATLAB.

The DAQ Toolbox does not release NI-DAQ driver DLLs on exit. Therefore you must exit from MATLAB.