Each time a CarMaker simulation program is started, it creates a new log file in the SimOutput sub-directory of the CarMaker project directory. As mentioned in the User's Guide an Programmer's Guide, the limit of this file is 10 MB.

This limit is hardcoded into CarMaker and cannot be changed by users. It was introduced due to misuse of the logging functionality (saving simulation results), which often led to file system overflow.

The log file should only be used for the most important information. We recommend to rework the log messages to need as less memory as possible. Think about the following points:
What is really important to know in the Session Log file? How many characters does my log really need? Which information can also be stored in an .erg or MDF file?

The .erg or MDF file format is much more suitable for result data and can handle a big amount of data (only values, no text messages). For more details about the handling of result files you can have a look in the User's Guide chapter 13.1 "Saving Results".

To handle a huge number of log messages of an FMU, you can have a look in the Programmer's Guide chapter 9.6.6 "Handling voluminous logging output"