Functional safety in industrial automation

Safety has to be an integral part of each machine. It is necessary in each mode of operation. Functional safety is that part of the overall safety that depends on the correct functioning of the machine control system. During the design of a machine all of its control functions have to be considered. Besides the functions relevant to control production also those functions that are necessary for safe operation, maintenance and setting have to be designed. After specification of the safety related control functions, the control system which is intended to perform these safety functions needs to designed and implemented. The paper shows an approach on how to design and implement a safety related electrical control system (SRECS).