| 摘要 |
An image forming apparatus includes an apparatus main body and a plurality of stages of option devices. An output connector of the apparatus main body is connected to an input connector of the option device in a foremost stage. An output connector of the option device in each stage other than an aftermost stage is connected to an input connector of the option device in a subsequent stage. An output connector of the option device in the aftermost stage is connected to ground. A main body control portion outputs a predetermined signal via the output connector of the apparatus main body when initial communication is performed. Each option control portion identifies in which stage of the option device the self-device is, on the basis of a voltage value of the predetermined signal inputted to an analog input port via the input connector. |
