IEC 61499 Component Based Approach for Batch Control Systems

In process automation batch processes play a dominant role. With ISA SP88 and its IEC standard equivalent IEC 61512, there is a standard available covering the description of batch processes and plants over several hierarchical layers. For the instrumentation and automation components in all industrial systems there is a trend towards distributed solutions. The function block oriented IEC 61499 standard describes models to implement distributed control systems. In this contribution a new way to combine the concepts of SP88 for design with the models of IEC 61499 for implementation is proposed. To describe the control sequences Signal Interpreted Petri Nets (SIPN) are used to get a more formal model of the control than it is possible with the Procedure Function Chart (PFC) proposed in SP88. Based on this description basic functions for the control as well as the corresponding activation sequences are determined. The basic components are implemented by function blocks according to IEC 61499. The interconnection of the function blocks according to the required sequences is implemented using a scheduler concept. This concept allows re-configuration of the control without altering the function block diagram. Hence the proposed approach offers analyzable formal models, re-usable basic components, and easy re-configurability. The approach is illustrated using the Festo Mini Pulp Process (MPP).