The big Arla Foods dairy in Slagelse has 12 large cold storage rooms where thousands of litres of milk is being stored for shorter periods every day. A Bitlink 2-wire bus system is used to monitor and actively adjust temperatures in these rooms.

A central computer is logging the temperatures to a database enabling it to tell when the cold storage rooms needs to be cleaned of hoar frost. Depending on the date and time, the software is also able to tell which persons to alarm in case of any problems.

Technical description of the installation

In the dairy a 2-wire bus system is installed together with a central computer. In each of the 12 cold storage rooms a PT100 standard temperature sensor and a DPBIT34-A1 sensor-amplifier registers and transmits data to the central computer through the bus system. The computer is linked to the bus system via a BIT2011 server.

Digital DPBIT40 output components makes it possible for the customized Bitlink software to actively control the refrigerator compressors, and therefore the temperature of the cold storage rooms, via the same 2-wire bus system.

The system also detects if any of the compressors have even small operational problems. DPBIT50 input components are used for this purpose.

All data is kept in a log in the Bitlink software which also contains the temperature profiles used in the facility and lists of people to alarm in case of any problems.

Components used: