Tracing is a function for analyzing events and finding errors in the software. Traces are configured by the developers in the logging.conf file. Everything that has been configured is entered in the log file. If necessary, you can send it to the Siemens service technician or hotline to analyze errors. Serial interface traces are generally only displayed at trace level TRACE configured in the logging.conf file. The PLC traces can be found in the /var/log/ois/localhost/[gateway] directory, for example /var/log/ois/localhost/1.