Patent ID: 8345283

Claim:
A communication system comprising: a first communication device; and a second communication device configured to be connected with the first communication device in a communicable manner, wherein the first communication device comprises: a first storage device configured to store identification information; a first processor; and first memory storing computer-executable instructions that, when executed by the first processor, cause the first communication device to: send the identification information stored in the first storage device to the second communication device; receive combination information sent from the second communication device; output status information included in the received combination information; and update stored contents of the first storage device such that identification information included in the received combination information is stored in the first storage device, wherein the second communication device comprises: a second storage device configured to store a plurality of items of combination information, each item of combination information including status information and identification information; a second processor; and second memory storing computer-executable instructions that, when executed by the second processor, cause the second communication device to: obtain status information concerning each of a plurality of types of status of the second communication device; update the stored contents of the second storage device such that the latest combination information, including the latest obtained status information and new identification information, is stored in the second storage device; receive the identification information sent from the first communication device; determine whether the received identification information is identical to the latest identification information included in the latest combination information stored in the second storage device; send difference combination information to the first communication device in a case where the received identification information is not identical to the latest identification information, the difference combination information including the latest identification information and difference status information, the difference status information being a difference between status information concerning the plurality of types of status corresponding to the received identification information and status information concerning the plurality of types of status corresponding to the latest identification information; and refrain from sending combination information to the first communication device in a case where the received identification information is identical to the latest identification information.