Safety switch for interrupting power supply to machine, checks switching state of two actuators by reading sub-words from code generator into evaluation unit

摘要

The switch has at least two actuators, and the power supply is only switched on if both are activated simultaneously. The actuators are connected to a code generator which outputs a numerical word that is divided into two sub-words. To check the switching state of the actuators, the sub-words are read synchronously into an evaluation unit (8). The value of each sub-word is influenced by a respective actuator. When the actuators are activated, the values of the sub-words is continuously varied. When one actuator is deactivated, the corresponding sub-word assumes a fixed predetermined value.