Patent ID: 8179918

Claim:
A relay connection unit, mounted on a vehicle, which is connected to a first communication line configured to communicate a first message by using a first communication protocol configured to communicate a message at time-divided time slots and a second communication line configured to communicate a second message by using a second communication protocol configured to communicate a message by attaching an ID (identifier) to said second message, said relay connection unit converting said communication protocols to each other to relay said first message and said second message, said relay connection unit comprising a first storage table in which said ID of said second message is assigned to each of said time-divided time slots configured to communicate said first message, a processing section configured to convert said second message received from said second communication line to said first message and sending said first message converted from said second message to said first communication line at said time slots assigned in said first storage table, a frame of said first message has a header segment and a payload segment showing a content of said first message, a frame of said second message has a data field showing a content of said second message, an arbitration field showing said ID thereof, and a control field showing a data length of said data field, and in executing communication by converting said second message to said first message, said processing section treats said data field of said second message as said payload segment of said first message and does not include said arbitration field of said second message and said control field thereof in said first message.