Disclosed is method of identifying a device that has been connected to
a multifunction apparatus to which any device of a plurality of types can be selectively
attached, wherein the method makes it possible to prevent malfunction if a device
is attached or connected unsatisfactorily. A timing signal for acquiring information
that identifies a device is transmitted to the attached device, identifying information
transmitted from the attached device in accordance with the timing signal is received,
and it is determined, with regard to a device of a specific type, whether specific
data contained in the identifying information is indicative of a predetermined
value. If it has been determined that the specific data is indicative of the predetermined
value, then control is exercised on the assumption that the connected device is
that of the specific type.