MP3.AC is the largest plant system of our chair. It is used for our laboratory courses and as a realistic test object for newly developed technologies. The field level of MP3.AC is based on the process-based model of a pumping station and makes up the centerpiece of the overall plant system. We are especially proud of the fact that different devices of a good number of manufacturers are utilized in our system. We have managed to include field devices of sixteen different in the plant system, while control systems of the six largest manufacturers are provided for process control. These can be alternately connected to the plant via the respective master cable. During our laboratory courses, the plant system is a well-appreciated basis for practical learning since similar devices are also used in industrial constructions.