Advanced Flour Mill

Weston Milling's new $ 25 million flour mill at Enfield in Sydney is one of the most advanced flour mills in the world. With a throughput of 24 tonnes/hour, the new plant can be operated by just two people.

Schneider supplied the advanced SCADA and PLC systems for the mill. The systems consists of five Telemecanique PLCs communicating over an Ethernet link, along with distributed field I/O modules running the FIP protocol. These modules use a mixture of dust-proof IP65 units and the standard IP20 devices.

Schneider also supplied 40 Altivar variable speed drives running on FIP. Schneider sub-contracted development of the SCADA system to TUSC.

Order: June 1995 Commissioned: August 1996.

Expandable Control System

The mill's process equipment was supplied by Buhler, the Swiss-based milling specialist; however, Weston Milling wanted to develop its own control system to be sure of good Australian support.

The automation system provides complete integration from the mill machinery and field sensing devices through to the business and management systems. It allows recipes and blends to be controlled by senior-level users and for the plant to be operated with ease. Replacing three outdated plants, the new mill can be started at the press of a button and run by the just two operators.

Productivity has increased to 24 tonnes/hour and the plant is more flexible allowing an infinite range of flours to be produced.

Quantum leap

Schneider's advanced FIP fieldbus technology, one of the reasons Schneider was chosen for the job, reduced cabling costs and improved the system's flexibility.

Able to communicate with the third party devices on the plant, the system is completely distributed.

The X-TEL software provided a well structured project management environment. With its graphical features and three languages - literal, ladder and Grafcet - it helped reduce development time and allowed the system to be developed 'on the run'.

The SCADA system, based on the Monitrol SCADA software, runs on two client servers with six operator stations. It generates the recipes and job information and downloads instructions to the PLCs. The system also provides plant graphics and mimics and displays any faults and alarms generated.