CS System Solutions, a division of JSE-listed CS Holdings, has successfully upgraded Plascon Luiperdsvlei`s water-based plant control system to Wonderware`s FactorySuite 2000 and Modicon`s Quantum PLC. This was done to increase flexibility, improve efficiency and quality, and achieve Y2K compliance.
Previously upgraded in 1994, the 140 000 litre-per-day plant was operating on an automation system using a Square-D PLC with a Genesis SCADA package, which produced batches effectively but did not have reliable reporting functions and offered minimal flexibility - any process change required significant re-programming and testing effort. "The change was mainly motivated by our Y2K upgrade," explains Plascon project engineer Lafras Heron.
"Rather than just replacing the SCADA, we went with the Plascon automation standard which is Wonderware software and Modicon hardware. The order was placed in March 1999, and we were fully commissioned by September."
The project saw the integration of the new hardware and software by CS System Solutions and engineered by Richard Mackay and Plascon engineer, Lafras Heron. "CS believes in working in strong partnerships with our clients to ensure the final solution is exactly what the business requires," says CS System Solutions MD Dave Vink.
The application utilises two components of the Wonderware FactorySuite - InTouch and InBatch - to control the production process. MS SQL server is used to store data for management reporting and Wonderware`s Industrial SQL server is used to store process analogue data.
Due to production demands, a procedure was needed to do the changeover and testing with minimal downtime and loss of production. An additional PLC cabinet was installed next to the existing one, wiring the I/O in parallel to both the old and new. The inputs were wired simply and the outputs were given a select switch, enabling the selection of either PLC.
"This allowed the team to work on developments offsite. When it came to commissioning we were then able to switch between the existing and new systems. Initially commissioning was run only during weekends, gradually increasing into the weekdays until we were comfortable it was running smoothly. At the end of commissioning shift each day we would switch over to the existing system, thereby maintaining uninterrupted 24-hour production at the plant," says Heron.
Once the I/O and the semi-automatic phases were commissioned, the Wonderware batch engine InBatch was installed, providing a management tool that instructs the PLC to execute and monitor the running of the phases and collects data associated with them.
Plascon expressed a strict requirement that production losses would not be acceptable during the testing and commissioning phases. "We therefore carefully scheduled the commissioning activities with Plascon`s production personnel, and simulated the new software prior to live commissioning with a view to meeting Plascon`s production requirements" says Dave Vink.
The Wonderware software and system design presents a number of benefits for the Plascon plant. The software is inherently flexible, allowing easy and efficient execution of any process changes and far more sophisticated control.
"The Factory Suite batching control programme allows the operators to draw recipes formulated by the chemists from the database and load it into the system, making up a batch strictly according to the formula designed by the chemist," explains Lafras Heron. This puts the control of the process in the hands of the factory chemist.
Detailed batch genealogy and reporting facilities are now available which enhances the efficiency of the plant, as well as providing a quality control check.
"The software allows us to determine the source of a problem promptly, solve the problem and track statistics, integrating the information throughout the factory. Hopefully in the future we will be able to relay this information directly into our business systems without any manual intervention," adds Heron.
The project was awarded the Wonderware Open (SA) award for 1999.
Share