Many of today's advanced fishing vessels are equipped with multiple units of the same equipment so that observations can be made from various locations within a ship simultaneously. There is a particular demand for a system that allows observations to be made from radar, sonar, and fish finders in a variety of locations. Conventionally, only the displays are placed in a variety of locations, but recently there has been a strong demand for a system that allows for the operation of the equipment at the observation location, especially in order to detect and pursue fish with scanning sonars. In response to this demand, JRC has developed a multi-display, multi-control device that allows for control between multiple displays through serial communication. This document will introduce that device.