The control part is the "heart" and "brain" of the whole system, and is the command center that realizes the function of the whole system. The control part consists mainly of the main console (some systems also have a sub-console). The main functions in the main console are: video signal amplification and distribution, image signal correction and compensation, image signal switching, image signal (or sound signal) recording, camera and its accessories (such as lens, pan/tilt, protection) Cover (etc.) control (remote control) and so on. Among the above-mentioned parts, the most influential effects on image quality are amplification and distribution, correction and compensation, and switching of image signals. In some cases where the camera is close to the control center or the overall system requirements are not high, there is often no correction and compensation part in the main console.