Switch device, in-vehicle communication system, and communication method

An in-vehicle communication system used in a vehicle in which a plurality of function units and a diagnosis device are installed,

• the system comprising a plurality of switch devices,
• each switch device including a plurality of communication ports, wherein
• each switch device is configured to relay a frame, which has been transmitted from a function unit and to which information including an ID of a VLAN is added, to another function unit,
• when the diagnosis device is connected to another switch device, a first switch device
• determines that the frame is a frame to be duplicated based on at least a source address and a destination address included in the frame,
• duplicates the frame to be relayed via a designated communication port among the plurality of communication ports,
• generates a duplicate frame for diagnosis that is a frame obtained by adding, to a duplicate frame obtained through the duplication, specific information indicating that the duplicate frame for diagnosis should be transmitted to the diagnosis device, and
• outputs the generated duplicate frame for diagnosis from a communication port corresponding to the other switch device,
• when the specific information is added to the frame received from the other switch device, a second switch device determines that the received frame is the duplicate frame for diagnosis and sets, to ON, a diagnosis flag of the frame that has been determined as the duplicate frame for diagnosis, and
• when the diagnosis flag is ON, the second switch device outputs the duplicate frame for diagnosis from a communication port corresponding to the diagnosis device among the plurality of communication ports.

A communication method for a switch device used in a vehicle in which a plurality of function units and a diagnosis device are installed,

• the switch device including a plurality of communication ports,
• the switch device relaying a frame, which has been transmitted from a function unit and to which information including an ID of a VLAN is added, to another function unit via a communication port,
• the method comprising:
• when the diagnosis device is connected to another switch device,
• determining that the frame is to be duplicated based at least in part on a source address and a destination address included in the frame,
• duplicating the frame to be relayed via a designated communication port among the plurality of communication ports, and
• generating a duplicate frame for diagnosis that is a frame obtained by adding, to a duplicate frame obtained through the duplication, specific information indicating that the duplicate frame for diagnosis should be transmitted to the diagnosis device;
• when the specific information has been added to the frame received from the other switch device, determining that the received frame is the duplicate frame for diagnosis, and setting, to ON, a diagnosis flag of the frame that has been determined as the duplicate frame for diagnosis;
• and
• when the diagnosis flag is ON, outputting the duplicate frame for diagnosis from a communication port corresponding to the diagnosis device among the plurality of communication ports.

A communication method for an in-vehicle communication system that includes a plurality of switch devices and is used in a vehicle in which a plurality of function units and a diagnosis device are installed,

• each switch device including a plurality of communication ports,
• each switch device relaying a frame, which has been transmitted from a function unit and to which information including an ID of a \IAN is added, to another function unit,
• the method comprising:
• when the diagnosis device is connected to another switch device, causing a first switch device to
• determine that the frame is to be duplicated based on at least a source address and a destination address included in the frame,
• duplicate the frame to be relayed via a designated communication port among the plurality of communication ports,
• generate a duplicate frame for diagnosis that is a frame obtained by adding, to a duplicate frame obtained through the duplication, specific information indicating that the duplicate frame for diagnosis should be transmitted to the diagnosis device, and
• output the generated duplicate frame for diagnosis from a communication port corresponding to the other switch device;
• when the specific information is added to the frame received from the other switch device, causing a second switch device to determine that the received frame is the duplicate frame for diagnosis and to set, to ON, a diagnosis flag of the frame that has been determined as the duplicate frame for diagnosis;
• and
• when the diagnosis flag is ON, causing the second switch device to output the duplicate frame for diagnosis from a communication port corresponding to the diagnosis device among the plurality of communication ports.