START/STOP Switch

The START/STOP switch represents a physical switch which can be used to set the PLC to the Start or Stop state.

This mechanism is active if the file /var/run/codesysextension/runstop.switch exists. Attention: Unlike the other functionalities of the Extension Package, the file in /var/opt/codesysextension/ is queried. This file is not created by the runtime system. You have to create the file if you want to use the START/STOP function. When the content of runstop.switch is "RUN", the PLC is started. When the content is different, the PLC is set to Stop.

The switch file is read cyclically. The PLC can be stopped and started at runtime.

If the runstop.switch file is deleted at runtime, then the component loses its function and the PLC starts.

Restriction: The Linux-based SL products which already have a START/STOP switch built into the hardware do not support this mechanism. These include the following products: