Here, the step chain is modelled in the logic layer. In the system layer, the parameters are assigned to the zones according to the steps. Further changes are made in the settings.
This tutorial deals with a single-acting (spring-return) cylinder.
A valve is actuated to extend the cylinder, while the cylinder is retracted by a spring. If the cylinder is to remain in the extended state, the valve must remain actuated.
Logic layer:
An InOut zone for the work position is created in the system layer; a workpiece is processed here, for example. An In zone is used to check the home position.
In this example, a processing step in which the cylinder must be extended follows as a timer. The "Keep-Alive" function in the InOut zone ensures that the valve remains activated in all subsequent steps in which an S - Sequence Check is set.
