Industrial Control Systems: Common ICS Types and Terminology Explained

An industrial control system or ICS is a type of control system that consists of a variety of different equipment and instruments used for observation, control, and potential automation of a system. These systems can be highly complex arrangements of devices and controls within a network that are used to monitor and execute a variety of industrial processes.

The actual devices and controls established in a given industrial control system will vary according to the nature and scope of the industry as well as with the complexity of the process involved. These are some of the more common types of industrial control systems, along with some proprietary terminology that is commonly used alongside them.

Types of Industrial Control Systems

• Programmable Logic Controllers (PLCs): A programmable logic controller, or PLC, is a hardware component of a control system that is often incorporated into other control systems, such as SCADA and DCS systems (see below). The PLC is user-programmable for I/O control, counting and timing, and more. A PLC can control the local management of certain industrial processes through sensors and actuators. They are actually designed to monitor large numbers of sensors and actuators and are typically highly resistant to adverse conditions such as extreme temperatures and humidity.

• Distributed Control Systems (DCSs): A distributed control system (DCS) is a sort of control system that is used to oversee and control the production in one given location. A distributed control system uses a centralized supervisory control loop in order to manage multiple local controllers within the greater system, giving operators the ability to access production and control data very efficiently. Because of this centralized supervision, DCS systems are able to minimize the impact of a single fault in the system. These types of industrial control systems are common in manufacturing, electrical power generation, and wastewater treatment.

• Supervisory Control and Data Acquisition (SCADA) Systems: SCADA systems are not intended to provide full control over a system; instead they are designed to gather information and relay it to supervisors at lower levels of control. Typically, SCADA systems consist of PLCs distributed throughout the system that collects data and relays it to supervisory level components. The primary value of a SCADA system is to gather and manage inputs and outputs from far-flung points within a system so that workers can access and monitor them remotely. This makes it possible for supervisors to oversee processes without needing to travel great distances to access information.

• Remote Terminal Unit (RTU): A remote terminal unit is a control system based on a microprocessor. These types of systems serve as electronic connections between different devices within the larger system. The RTU may be a component of a DCS or SCADA system, in which case it will pass data from one of the control loops within the system to the higher ICS command center.

• Programmable Automation Controllers (PACs): A programmable automation controller is a type of controller that can be programmed to relay complex instructions to a system. PACs offer expanded connectivity to many systems and are commonly used in vision, motion, and logic systems.

• Industrial Automation and Control System (IACS): Industrial automation and control systems often include smart devices for information collection, processing, and distribution. They can be used to improve communication and automation within a system, and often consist of both software and hardware, including sensors and machines. IACS are commonly used for facility management, system integration, machine logic control, process control, integrated manufacturing, and often include various HMIs, or human-machine interface devices.

• Intelligent Electronic Devices (IEDs): An intelligent electronic device is an electronic component of a system that has a microprocessor and can communicate data with other electronic devices. Many industrial control systems use these and their applications are widely encountered in a variety of industries, including but not limited to manufacturing, mining and chemical refinement, water treatment and processing, and much more.

Common ICS Terminology

Different types of industrial control systems are supported by a variety of components, and certain terms are common in the industry. An entire volume could be filled with industry-specific terminology, but the following are some of the most common among them.

• Human-Machine Interface (HMI): An HMI is a GUI (Graphical User Interface) that allows a human operator to communicate with a piece of hardware within an ICS. They may be able to store data as well as display it, enabling monitoring and configurations of controllers and parameters.

• Control Loop: A control loop controls hardware and software within the system, such as the sensors and actuators, in order to achieve the desired value as the output of a process.

• Control Server: A control server is a computer that communicates with and controls subordinate components of an industrial control system through supervisory control software.

• Remote Diagnostics and Maintenance: Remote diagnostics and maintenance are an established series of applications that run real-time scans to identify and prevent abnormal operations to prevent output from being adversely affected.

• Front End Processor: A front-end processor (FEP), which is sometimes also known as an input-output server (IOS) and is a device that relays system data, potentially to operators that need it to make corrections to processes within the system.

• Communication Gateway: A communications gateway is a device that restricts or enables the flow of information inside and outside of the network. It can allow components within the system to communicate with external networks, like the internet, or restrict external access to the system, to protect against threats such as cyberattacks.

• Data Historian: The data historian within a system is a centralized database that contains all of the data associated with the system’s operations. The data may be exported for review, to perform audits, or to improve process controls.

Contact Us for More Information

Interested in learning more about the control components of industrial control systems that are used in the monitoring and control of water and wastewater treatment systems, manufacturing, transportation, and elsewhere?

Get in touch with us at 800-966-2345 and let us know how we can help outfit your ICS, we’d be glad to help.