The following PLC Architecture will control the process of a gas compressor station.
The Architecture is divided in 2 control systems.
-Process Control System (PCS)
-Safety Instrumented System (SIS)
PCS & SIS follow ring topology for I/O cards.
The SIS must be redundant, in order to ensure safety process control!
For PCS we use ControlLogix PLC 1756-L71.
For SIS we use 2 ControlLogix PLCs 1756-L71, each equipped with
1756-RM2/A Redundancy Module.