The Equipment Development Division of BOC Gases, UK makes industrial systems for food processing based on the use of cryogenic gases. The Division has to design, build and deliver to tight deadlines since suppliers to the food industry are not short of competitors.
Further, equipment is often secured on a short term basis and rented for the shortest possible period. An order required BOC Gases to design, build and ship a number of Fluidized Bed Freezers within 12 weeks. The design, production and installation costs had to be minimized; user intervention for set up, control and maintenance also had to be minimized too; and the system had to be built 'right first time' using a number of untried components.
A fieldbus-based solution was the obvious choice. It was decided to use a PROFIBUS-DP system because of the standard proven interface and its ability to provide detailed data from networked components, such as calibration data from the pressure gauges (not usually available).
A modular design was used to allow parts of the machine to be built independently and integrated later. The first production unit was built alongside the prototype - which was completed in three weeks - enabling software tests to be carried out early. An A series PLC, The PROFIBUS network was particularly easy to configure using Mitsubishi's Windows-based configuration software, which took just five minutes to map the entire network.
Using PROFIBUS, faulty modules are immediately identified, complete with a fault analysis. Setting the inverter parameters is easy too.
Hugh Sullivan, Project Engineers for BOC Gases says: "using Mitsibushi's PROFIBUS products gave us an open, modular approach that enabled us to use a variety of components and put them together very quickly." Mitsubishi's goal is to add value to the PROFIBUS standard by providing high performance control products and easy to use integration tools. The open PROFIBUS standard not only allows the best products to be selected but also allows engineers to spend less time on the hardware and more time on end users' needs.
Mitsubishi participated in the developement of the plant.