Industrial control system architecture
An ICS is a generic term used for all industrial systems that perform data acquisition, monitoring, and supervisory control of local and remote devices and assets. In the previous section, we talked about SCADA, DCS, and PLCs, which are the basic building blocks for centralized monitoring and control of distributed assets and operations, which are sometimes scattered over thousands of square kilometers. The following diagram shows the various functional levels of a manufacturing control system:
From the preceding diagram, we come to know of the following:
- Field devices such as sensors and control valves in level 0
- Industrial microcontrollers and input/output (I/O) modules, which are shown in level 2
- Control room elements, including supervisory computers with consolidated process information and operator control screens, which are in level 2
- Production control, which is shown in level 3, is mainly concerned with the monitoring of production activities and assets
- Production scheduling functions are captured in level 4
Field devices are remote station control devices that can act on either automated or operator-driven supervisory commands from central control stations. These control stations generate commands, such as for opening or closing valves and breakers, collecting data from sensor systems, monitoring local environments for alarm conditions, and so on, based on information received from other remote stations (NIST-800-82r2).
These are industry-specific components that interface with digital or analog systems and expose data to the outside digital world. They provide machine to machine, human to machine, and machine to human capabilities for ICS to exchange information (real-time or near real- time), thus enabling other components of the IIoT landscape. This includes sensors, interpreters, translators, event generators, loggers, and so on.
Plant devices and equipment include sensors and actuators, control valves, and so on, which sense and act on commands from ICS.
The following diagram shows the various components of an ICS/SCADA system:
