Changeover Switch - Siemens SIMATIC S7-200 Getting Started

A.3

Changeover Switch

Changeover switches should likewise not cause you any problem when you are converting a
circuit diagram into a ladder diagram. This transformation is explained below.
The current paths are highlighted.
Changeover switch b is then divided into a normally closed (NC) contact that is switched in
series and contributes to the effect at output C, or a normally open (NO) contact that takes
effect in parallel with a and switches D.
In principle it is possible to convert a changeover switch using an NC contact and an NO
contact with the same input address in the ladder diagram.
Getting Started - Advanced
Training Documents, 09/2007, A5E01469795B
Appendix A
A.3 Changeover Switch
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