Interfacing Modern Drives with Mill Distributed Control Systems

Present-day drive systems are all-digital and have taken on the characteristics of a drive-level distributed control system with a high-speed communications system encompassing the master, drives, and operator's controls. The interface with the next higher level in the mill control hierarchy, the distributed control system, must reflect these characteristics. The speed of response required for direct manipulation of the drive system is very fast. Consequently the slower distributed control system is used primarily to monitor and perform relatively long-term control functions on the drive system. Local machine operator controls are required for safe direct command control of the sections. An adequate communications link may be established through conventional programmable controller highway protocol and hardware.