Every time,I run the simulation ,I see a warning message saying “verbose mesage decreases real-time performance!” I tried cleaning the code directory. still i see this issue.
is there a permanent solution for this
Hi,
- Why Cleaning the Code Directory Does Not Resolve This
Cleaning the code generation directory (or clearing slprj / temporary build folders) only deletes previously compiled binaries and cache files.
However, Verbose Mode is a persistent configuration setting saved inside the model parameters (.slx/.mdl), the RT-LAB project configuration, or the communication driver masks. As soon as you rebuild or start the simulation, the model re-generates the real-time executable with verbose logging enabled.
- Why This Warning Appears in Real-Time Simulation
In hard real-time simulation on Linux/QNX targets, writing text messages (printf, std::cout, disp, or driver console logging) to stdout/stderr during the simulation step involves non-deterministic operating system I/O calls. These I/O operations stall the execution thread and can easily lead to timing overruns (missed time steps).
The software generates this warning to alert you that active verbose/diagnostic logging is consuming target processor cycles.
- Step-by-Step Permanent Solutions
Please check the following four locations where verbose flags are typically enabled:
Location A: Simulink Model Configuration Parameters (Code Generation)
In MATLAB/Simulink, open your model and press Ctrl + E to open Model Configuration Parameters.
Navigate to the Code Generation tab in the left pane.
Under the General options, locate and uncheck “Verbose” (or set Verbose on build = off).
Save the model (Ctrl + S) and rebuild in RT-LAB.
Location B: RT-LAB Model Properties & Execution Settings
In the RT-LAB Project Explorer, select your model or target node.
Go to the Properties / Execution Options tab (or Simulation Controller settings).
Look for “Verbose mode” or “Display verbose execution messages” and uncheck it.
Set the Console / Log Verbosity Level to Normal or Errors/Warnings only instead of Verbose / Debug.
Save the RT-LAB project (.opal).
Location C: Communication Driver Blocks (I/O, Async, C37.118, CAN, SCPI, OpComm)
Many communication blocks and protocol drivers in RT-LAB include a diagnostic verbose toggle:
Check any communication / I/O blocks in your model (e.g., C37.118 Master/Slave, Async Controller, SCPI Driver, OpComm, OpCtrl).
Double-click to open the block mask/configuration dialog.
In the General or Advanced tab, uncheck “Enable verbose mode” or “Print diagnostic messages”.
Save the model and recompile.
Location D: Custom C S-Functions / MATLAB Function Blocks / UCM
If your model contains custom C/C++ S-Functions, User Code Models (UCM), or MATLAB Function blocks:
Ensure there are no active printf(…), std::cout, or disp(…) calls inside the main calculation loop (e.g., mdlOutputs or mdlUpdate).
Comment these out or wrap them in preprocessor directives so they only execute offline during debugging:
#ifdef DEBUG_OFFLINE
printf(“Debug value: %f\n”, var);
#endif
Hi,
Please try to uncheck “Enable Simulation Logging”. It should fix this message
Usually, you enable this option to have more information displayed in the simout panel and help to debug initialisation or running a simulation. However, when the debug is completed, you should uncheck it.
Hi @Parija,
I am currently working with HYPERSIM, so the RT-LAB-related suggestions may not be applicable to my setup. Nevertheless, I appreciate your prompt assistance and the information shared.