IEC 60870-5-104

Stadtwerke Heide GmbH supplies electricity, gas, water and heat to about 35,000 inhabitants, many households and businesses in Heide and the surrounding communities. In addition, it runs the outdoor and indoor swimming pool “Dithmarscher Wasserwelt”. The public utility is traditionally firmly rooted in the region and plays an important role in the economic and social life of the city of Heide.


It is more than just an anonymous supplier of energy and water. Heide Stadtwerke GmbH faces the open market competition with a high level of motivation, competitive prices and well-trained specialists.

Step by step to the goal

A few years ago, Stadtwerke Heide decided to replace the decrepit PLC controls on the waste water treatment plant with modern telecontrol technology from SAE IT-systems. Even after the founding of the waste water special purpose association in Heide, the conversion was continued under the supervision of Stadtwerke Heide. Within the scope of the project, the individual functional units, e.g. the aeration, the equalisation tank, the inlet, the screen, the return sludge, the excess sludge thickening, the secondary clarification, the filtration and the main distribution of low voltage were renewed in stages over several years.

Technical specifications

In total, nine PLC systems with a capacity of approx. 1,200 digital inputs, 250 digital outputs and 100 analogue inputs and outputs were replaced. For this purpose, net-line FW-50 stations, partly cascaded, were set up in the existing cabinets.
The systems are operated with a loop concept using SHDSL modems (MiniFlex from FlexDSL) in the TCP/IP frame with IEC 60870-5-104 protocol and forwarded to a ProCoS control system. The ring loop concept represents a substitute routing within the SHDSL modems, thus ensuring data transmission in the event of a data transfer failure.

“Good things come to those who wait. Although the conversion had to be carried out in stages and thus took a long time, SAE kept an eye on the overall goal and completed the project completely smoothly and to our utter satisfaction. That’s the way to work!”
Jan Nagel, Stadtwerke Heide