ICS is a general term used to describe the integration of hardware and software with network connectivity in order to support critical infrastructure. An ICS is a system that handles process control and monitoring for the facility. It will take inputs from sensor and process instruments and provide output based on control functions in accordance with approved design control strategy.
The structures of ICS architectures are diverse, and depend upon system requirements, process function, and business needs. Vendor solutions sometimes dictate using specific ICS architectures; however, depending on the functionality and the complexity of the control action, there are common elements seen across all ICS architectures. Over the next few pages, we will discuss a few of those architectures.
We should note that the differences between systems are diminishing as the capabilities merge. To reduce the confusion among the various types of control systems, we refer to them by their generic name, industrial control system (ICS).