Implementing Non-Linear Strategies for PID in IEC 61131-3 ST Language

Industrial process measurement and control systems (IPMCS) are used in most of the industrial sectors to achieve production improvement, process optimization and time and cost reduction. Integration, reuse, flexibility and optimization are demanded to adapt to a rapidly changing and competitive market. The standardization of high level programming languages for programmable logic controller (PLCs) allows implementing more advanced control strategies in PLC based control applications. In this paper, antiwindup (AW) and bumpless transfer (BT) mechanisms for PID control have been selected to be implemented as reusable functional block (FB) program organization unit (POU). In particular, the final objective of the work is to design a mode switching supervisor for hybrid control systems.