Definition Loop

Definition Loop is an integrated system to combine the instrument field devices (inputs) and (output) to the field with its network control system connected to the wiring.
Open Loop is a one-way relationship of field signals (inputs) to the control system or otherwise (output) from the field to the control system. Input and output do not have a relationship. So when the action field to change the output of the process, no feedback is given to the loop.

Closed Loop is a cycle signal from the field (input) to the control system is then processed and generates the output signal which is sent back to the final element in the pitch (output). And the action of the final element that will have an effect on the input.
Pre-Commissioning is activity to ensure that each instrument input devices, control systems, and the final element instrument can operate as control design to support the process. Pre-commissioning can also be called a test function for each loop.
Commissioning is the activity to create a system of 'LIVE' and is operating normally. Commissioning involves a multidisciplinary and multi-loop. Instrument and control system must be able to function normally to control multidisciplinary systems (processes, electrical, mechanical) that are running and also maintain safety protection systems in critical condition.
Definition Loop to music, in electroacoustic music, a loop is a repeating section of sound material. Short sections of material can be repeated to create ostinato patterns. A loop can be created using a wide range of music technologies including digital samplers, synthesizers, sequencers, drum machines, tape machines, delay units, or they can be programmed using computer music software.