Siemens SIMATIC S5 Manual page 16

Depending on the configuration of the controller as a 2 or 3-step controller, the 17 digital outputs
are assigned consecutively. The maximum number of controllers is determined by the required
number of digital outputs (maximum 17).
Example of controller configuration
You require cascaded control with controllers 1, 2 and 3 as 3-step controllers and controllers
4, 5 and 6 as 2-step controllers, all other controllers are disabled.
The assignments of inputs and outputs is shown in the following diagram:
The remaining analog inputs are used only for measured value acquisition, the remaining digital
outputs are not used.
IP244
C79000–B8576–C859–02
Installation
2–13