Programmable controllers for special control applications in rolling mills

Programmable controllers were originally evolved as programmable logic controllers to be used solely for replacement of hardwired logic schemes. In the course of time the PLC hardware has become more powerful and programmable controllers are taking their designated place deservingly in the upper range automation systems and handle some of the special control functions which were hitherto being executed only by process computers or analog controllers. The paper deals with automation of a single stand aluminium cold rolling mill using programmable controllers and PC´s. It highlights the various special functions realized using the programmable controllers