A switch with automatic restart is modeled here. The step chain is mapped in the logic layer and the parameters are assigned in the system layer.
Process in the logic layer:
The system is designed to run continuously after the switch has been switched on once until the switch is switched off again. For this purpose, a jump command (Jump) is inserted, which is placed in step 2 "Switch ON", where the switch is switched on and queried. This command checks the status of the switch in this step. In the system layer, the operand J - Jump is defined in the zone of the switch and performs a jump to step 2 "Switch ON" as long as the switch is active.
If the system is switched off, the system jumps to step 1 "Switch OFF" and waits again for step 2 "Switch ON" until the system is switched on again. In this case, no I - Interlock Checks would be set in the following steps.
System Layer:
