マスターモニター

noun

master monitor

A primary or control monitor in a multi-display setup, often used in broadcasting, security, or audio-visual systems.

• 放ほう送そう室しつでは、マスターモニターで全ぜんチャンネルの映えい像ぞうを確かく認にんする。

  In the broadcast room, they check the video of all channels on the master monitor.