Patent ID: 7853729

Claim:
A method of performing a self diagnosis of a single device that includes a universal serial bus host and a universal serial bus client, the method comprising the steps of: (a) detecting whether the universal serial bus client of the device is connected to the universal serial bus host, wherein the device comprises a function of at least one of a printer, a facsimile machine, a multi-functional device, and a scanner; (b) detecting whether the device acting as the universal serial bus client is identical to the device acting as the universal serial bus host when the universal serial bus client is connected to the universal serial bus host, wherein step (b) comprises the steps of: (b1) receiving product identification and serial number of the universal serial bus client at the universal serial bus host from the universal serial bus client; (b2) comparing product identification and serial numbers of the universal serial bus host and the received product identification and serial number of the universal serial bus client; and (b3) determining that the device acting as the universal serial bus client is identical to the device acting as the universal serial bus host when the product identification and serial number of the universal serial bus host and the product identification and serial number of the universal serial bus client are the same, respectively; and (c) directing the self diagnosis of the device to be automatically performed when the device acting as the universal serial bus client is identical to the device acting as the universal serial bus host.