Browse Definitions :
Definition

control loop

Contributor(s): Matthew Haughn

A control loop is a system made up of all the hardware components and software control functions needed for the measurement and adjustment of a variable that controls an individual process.

Control loops are the elemental building block of industrial control systems (ICS) such as supervisory control and data acquisition (SCADA) or distributed control systems (DCS). Each control loop commands a given variable in an industrial process.

Found everywhere ICS are used, control loops are part of the systems used in several processes, including:

  • Agriculture
  • Chemical plants
  • Pulp and Paper Mills
  • Quality control
  • Boiler controls and power plant
  • Nuclear power plants
  • Environmental control
  • Water treatment plants
  • Sewage treatment plants
  • Food and food processing
  • Metal and mines
  • Pharmaceutical manufacturing
  • Sugar refining plants

A control loop is made of a number of components. Though the specifics vary, a control loop is generally made of a sensor, a controller and a final control element.  The sensor takes a reading of the process variable or a related measurement. The controller receives the signal from the sensor and then forwards it to instrumentation, to remote terminal units (RTU) and to final control elements where the process variable is adjusted, to be kept as desired at a set point.

There are two main types of control loops: open loops that take human input and closed loops that are fully autonomous. Some loops can be switched between closed and open. When open, a switchable loop is manually controllable and when closed it is fully automated.

This was last updated in September 2017

Continue Reading About control loop

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • risk management

    Risk management is the process of identifying, assessing and controlling threats to an organization's capital and earnings.

  • compliance as a service (CaaS)

    Compliance as a Service (CaaS) is a cloud service service level agreement (SLA) that specified how a managed service provider (...

  • data protection impact assessment (DPIA)

    A data protection impact assessment (DPIA) is a process designed to help organizations determine how data processing systems, ...

SearchSecurity

  • computer worm

    A computer worm is a type of malicious software program whose primary function is to infect other computers while remaining ...

  • Single Sign-On (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials (e.g., ...

  • Certified Information Systems Auditor (CISA)

    Certified Information Systems Auditor (CISA) is a certification issued by ISACA to people in charge of ensuring that an ...

SearchHealthIT

SearchDisasterRecovery

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • disaster recovery team

    A disaster recovery team is a group of individuals focused on planning, implementing, maintaining, auditing and testing an ...

  • cloud insurance

    Cloud insurance is any type of financial or data protection obtained by a cloud service provider. 

SearchStorage

Close