1) Make sure that the Simulink Data Inspector is working as expected by running the example below which does not use Simulink Real-Time.
2) Try the shipped example of logging signal in SDI for real-time models:
3) Check the MATLAB Command Window for warnings about non-observable signals when you are running your own model. See the following post for details:
https://www.mathworks.com/matlabcentral/answers/773802-why-am-i-unable-to-log-or-stream-signals-when-my-application-is-running-on-hardware-external-mode-a
4) If the above steps are all good except signal logging in SDI, revise the firewall and antivirus settings on your development computer:
