In many instances, a system or machine will report an error that is difficult to diagnose by looking only at the PLC code. In these situations, you will observe the problem but you won’t be able to pinpoint its root cause. This will result in a lot of time and effort in troubleshooting the problem.
This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/siemens-plc-troubleshooting-using-traces-in-tia-portal