Client: Aspen

Project Requirements

The client manufactures baby formula. The process consists of a stainless steel bin moving through three to five different stations, depending on the product being manufactured.

The different stations are

• Blending Station 1
• Blending Station 2
• Tumbling Station 1
• Tumbling Station 2
• Tumbling Station 3
• Discharge Station
• Cleaning Station

It was required that the bin should not be offloaded, unless mixing had taken place. It was also required that if the bin had been through 10 production cycles, then it should be locked out until cleaning had taken place.

Client: Kalagadi Manganese

Project Requirements

The client built an ore handling plant to supply ore to an existing sinter plant, and transport the sintered product out to railway wagons. ControlNET Consulting was required to develop and commission the control software for this new plant as well as interface it with the existing Sinter Plant control system.

The Control was implemented using the Siemens PCS 7 platform. Motors were controlled using ABB VSDs and Siemens simocodes on profibus. A sophisticated, easy to use and maintain system was handed over to the client under budget and on schedule.

Client: Eskom

Project Requirements

The control system of Eskom’s Dust Handling Plants had reached it’s end of life. The S5 PLCs were no longer supported by the OEM, with no spares readily available on the market. It was also difficult to maintain them because of limited know-how availability. ControlNET Consulting was tasked with replacing them with S7 PLC hardware and software.

New panels were made to replace the existing S5 PLCs. The old panels were removed, while leaving the field wiring intact. In order to give the client the benefit of the new hardware and software platform, it was necessary to reverse-engineer the old software and derive the control philosophy. The software was then implemented with new function blocks and faceplates, making it more informative for the operator and easier to fault-find and maintain.

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.

Client: Glencore

Project Requirements

The Client had a PCS 7 v7.1 control system running on the Windows XP and Windows Server 2002 Operating systems. These had been discontinued by the OEM and were no longer supported. This presented two risks:

• there were no new security updates, and the system was therefore vulnerable to cyber attack
• a PC hardware failure meant the PCs would be difficult to replace since new PCs did not support the old operating systems

The Windows OS upgrade also required a PCS 7 version upgrade. This increased the life of the control system, eliminated vulnerabilities and opened up the system to enhancements offered by the new version of PCS 7.