Patent ID: 7752029

Claim:
A method for enabling a USB (Universal Serial Bus) device to emulate a USB target device by changing operation of the device, enabling the device to serve as a test jig for the installation and set up concerning the target device, comprising: providing a device emulator within the device; attaching the device to a host device; identifying the device being a printer device by setting default device descriptors; sending at least one target device descriptor, which is the at least one device descriptor of the target device, to the device emulator, by making a print job containing extended PJL (Printer Job Language) commands corresponding to the least one target device descriptor and sending the print job from the host device to the device using a generic driver; the device emulator processing the at least one target device descriptor and storing the at least one target device descriptor as at least one current descriptor in a memory of the device emulator; and the device emulator responding to a query from the host device by operating according to an operation of the target device by emulating the identity of the target device, which identity is specified by the at least one current descriptor.