Electrical, Control, Instrumentation Engineering and Consulting services

Project: MSP Plant Network Split

Client: Kenmare Mooma Sands

Project Requirements

The client’s plant was controlled by a single S7-400 PLC, a redundant server pair and 6 client stations. Due to the large quantity of devices on the profibus network, the client consistently experienced network problems resulting in long plant stoppages. Although the plant could be logically split into seperate distinct areas, it was not possible to work in one plant area without stopping the whole plant. ControlNET Consulting was asked by the client to solve this problem for them.

This was a mammoth task requiring upfront detailed design and planning. Our solution was to split the plant into five logical areas. Each area was assigned a PLC with it’s own network. New fibre optic networks were run for each PLC due to the long distances involved and the amount of interference sources in the plant. New remote IO stations were built and connected to the new PLCs. The plant devices were re-allocated to the new PLCs, and the field wiring was changed accordingly . With all these changes, it was necessary to modify the PLC and SCADA software. It was also necessary to exchange information across the PLCs and this was achieved over an ethernet network. With minimum downtime available to implement these changes, it was important to do thorough preparation and testing upfront.

At the end of the project, the client had a stable plant, in which he could isolate plant portions without stopping production in others.