Patent ID: 8495162

Claim:
A communication system in which a plurality of communication apparatuses and a communication control apparatus provided in a daisy chain configuration, and each communication apparatus relays data from one side of the communication system to another side, wherein the communication control apparatus comprises: a transmission unit to transmit, to the plurality of communication apparatuses, a command message comprising a plurality of command fields, each of the command fields having a command code and a parameter code, each of said command codes including respective operation delay information for each communication apparatus; and a reception unit to receive communication data transmitted by the plurality of communication apparatuses, and each communication apparatus comprises: a command reception unit to receive the command message from an upstream side of the daisy chain configuration; a communication data generation unit to generate communication data at a timing being based on the operation delay information included in the received command message; a command transmission unit to transmit the received command message to a downstream side of the daisy chain configuration; a communication data reception unit to receive communication data generated by another communication apparatus from the downstream side; and a communication data transmission unit to sequentially transmit, to the upstream side, communication data generated by the communication data generation unit and the communication data received by the communication data reception unit; each of the communication apparatuses further comprises a command data extraction unit to extract a command code and a parameter code contained in a first one of the command fields in the received command message sent by the communication control apparatus, the first one of the command fields being located within the command message immediately prior to subsequent command fields, each of the command codes identifying a respective command to be performed by a respective one of the communication apparatuses, each of the parameter codes defining a respective parameter directly relating to the respective command code; each of the communication apparatuses, upon processing the command identified by the respective extracted command code, deletes or changes to an invalid code said command code within the respective command field of the command message, prior to transmitting the command message to the next communication apparatus in the daisy chain configuration.