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A control loop is the fundamental building block of control systems in general and industrial control systems in particular. It consists of the process sensor, the controller function, and the final control element (FCE) which controls the process necessary to automatically adjust the value of a measured process variable (PV) to equal the value of a desired set-point (SP).
Instrumentation comprises sensor elements, signal transmitters, controllers, indicators and alarms, actuated valves, logic circuits and operator interfaces. An outline of key instrumentation is shown on Process Flow Diagrams (PFD) which indicate the principal equipment and the flow of fluids in the plant.
Note that a 4-wire instrument has a power-supply input separate from the current loop. Panel mount displays and chart recorders are commonly termed "indicator devices" or "process monitors". Several passive indicator devices may be connected in series, but a loop must have only one transmitter device and only one power source (active device).
Its name comes from the information path in the system: process inputs (e.g., voltage applied to an electric motor) have an effect on the process outputs (e.g., speed or torque of the motor), which is measured with sensors and processed by the controller; the result (the control signal) is "fed back" as input to the process, closing the loop. [1]
There were no allied vessels in the harbour so the indicator loops on the minefields were activated. Two hours later, at 23:32, current was detected in an indicator loop laid in a remotely controlled minefield, induced by the submarine as it passed over the cable. Activation of the loop detonated mines in the field, sinking the submarine. [10]
Loop performance in control engineering indicates the performance of control loops, such as a regulatory PID loop. [1] Performance refers to the accuracy of a control system's ability to track (output) the desired signals to regulate the plant process variables in the most beneficial and optimised way, without delay or overshoot.
Each loop or circuit maybe identified using a unique code, with description about; process, material & degradation mode, material, cladding, C.A, specs. See system model comes under the general heading of system analysis the terms analysis and synthesis come from Greek where they mean respectively "to take apart" and "to put together".
Stack light in automated production for in-line quality inspection. Stack lights (also known as signal tower lights, indicator lights, andon lights, warning lights, industrial signal lights, or tower lights) are commonly used on equipment in industrial manufacturing and process control environments to provide visual and audible indicators of a machine's status to machine operators, technicians ...