Method and system for safety-relevant input to a control system

A method for safety-relevant input to a control system, the control system including a non-safety control module configured to control non-safety processes, and a safety control module configured to control functional safety of processes, the method comprising, using an operator panel for user selection of safety-related object input:

• selecting a safety-related object on the operator panel;
• transferring object code and masked object code between the operator panel and the safety control module in both directions;
• using two different communication paths, a first communication path for the object code and a second communication path for the masked object code, each communication path going through the non-safety control module;
• and
• using reference code values stored on the safety control module for verifying for correctness the object code and the masked object code received in the safety control module.