The SRB 100 DR safety monitoring module ensures the safety of machine operators when they are performing repairs or maintenance in hazardous zones with shut-down machine control. Introduced as an extension to the PROTECT-SRB safety relay range, the SRB 100 DR ensures that the machine control can only be switched on after the operator has activated both reset buttons in the correct order and left the hazardous area. Failures such as welded contacts cannot lead to dangerous situations.