Data Logging, Technological Diagnostics and Adjusting Criteria for a Steel Tube Rolling Mill

Abstract Direct Digital Controllers command the most important DC motor drives of the seamless tube plant. Using free CPU time and memory of these regulators, programs were developed and implemented to sample the principal rolling magnitudes, such as current, power, speed and separating forces. This data is transferred from each digital regulator to the cell controller in successive data packages using RS 422 communication channels and a Modbus protocol. During the rolling process the alarms and the most important variables appear on a colour screen. With curves, alarms, conclusions elaborated by a simple rule based system and results of mathematical models, the operator can modify the machine set-up to improve the performance of the production machines.