Defiance Maize Products are located in Warwick on Queensland's Southern Downs, where their mill processes maize products for human consumption.
The control system for the mill was a legacy Siemens S5 PLC with ET100 remote I/O distributed across the plant. Maintaining the plant was becoming a challenge as replacement parts could be hard to locate and the location of some remote I/O racks made them vulnerable to lightning and power disruptions.
Downey Engineering had been involved with the ongoing maintenance and improvements of the plant over many years and was pleased to use both their extensive site knowledge and Siemens programming capability to be part of the upgrade project.
The upgrade from Siemens S5 to Siemens S7-300 PLCs also gave the opportunity for some code revision to take advantage of the enhanced PLC capabilities.
To convert and improve the Siemens S5 program into Siemens S7. A 4-day changeover period was allowed for hardware changeover and re-commissioning.
A Siemens S7-317F Processor paired with cost-effective VIPA I/O on a Profibus DP network. Siemens OLMs were chosen to provide optic fibre link to remote racks. Citect SCADA was upgraded to Version 7.1 with widescreen monitor and updated graphics. Remote Access via dial-in replaced with on-demand ethernet connectivity to the secure Downey Engineering support portal.
- System hardware upgraded over two days with recommissioning undertaken on Day 3.
- A fully functional plant back in production by day 4.
- A satisfied client with a solid foundation for the next phase of their plant life.