Our job was to develop a control system for an elevator system with several elevators on a SPS SIMATIC C7-626 (This is a product of Siemens). This control system should be simply adaptable for different elevator systems. As test system we have used a Fischertechnik-model with two elevators. Each elevator has four floors. We had to use the S7-SCL programming language.

At first sight it seems that an elevator control system is a simple thing, which doesnt indicate large problems. But unfortunately it isnt like that in reality. These elevators form a " dynamic " system which can assume a lot of different states. For a solution which is comfortable for the user, we had to thought out almost every possible situations.

In order to solve our job we have built functional groups (modules) and defined interfaces between them. Then we divided the modules into smaller function blocks, because we wanted to reduce the complexity of our program modules. During this phase we defined the request specification. The next step was to describe the function of the blocks with Nassi-Schneidermann- or with SDL-diagrams. And then we programmed the code.

During the implementation phase we had some problems with the realisation of our concept because of the block concept of the SIMATIC that also exists in SCL. So it need additional time to implement certain things. Anyway it was an interesting work to process a large automation project.