The I/O system for the E°EXC-89 CNC controller generation from Eckelmann makes it easy to integrate simple safety functions that previously required separate safety relays without the need for additional wiring. The safe power supply module E°UBM 02DI-PS-O-D-S enables safe disconnection of the output current path of the downstream modules. This allows, for example, two emergency stop circuits to be monitored or light grids to be seamlessly integrated into the I/O system. It switches off all downstream modules that are supplied by the output current path, thus forming a safety segment. The power supply module reports its status to the PLC. The integration and intelligent diagnostic functions allow the fault to be identified quickly. Another function is the evaluation of test pulses in the safety circuits, which can be used to detect cable breaks or contact loss. With additional power supply modules, several safety circuits can also be implemented in a cascade. Eckelmann customers can also use the fully integrated E°SLC-89 safety controller with FSoE, the Ethercat safety protocol, to monitor decentralized safety devices or implement more complex safety functions. A convenient graphical programming environment with function blocks is available under Codesys V3 for programming the safety logic.