Fail-safe operation and reliability enhancement of distributed process plant with PLC

Safety and reliability of distribution system has considered while designing the control system configuration. The reliability values are computed for various configurations. A redundancy approach which makes the outputs fail-safe, and enhances reliability is designed around PLC. The design is based on the use of dynamic logic, suitable for its implementation in digital instrumentation & control systems and, in particular, in PLCs of low and medium range. Also reliability for the proposed systems are calculated and presented in this paper.