An apparatus operable with a system which includes a body-side device and wheel-side
devices and in which vehicle-state data such as wheel-state data representative
of wheel states are transmitted by radio communication from the wheel-side devices
to the body-side device, together with wheel identification data identifying the
wheels. The apparatus includes antennas attached to each wheel inspecting device
which is arranged to rotate the corresponding so that the antennas are sequentially
aligned with the wheel-side device, and transmit trigger signals in response to
which the wheel identification data are transmitted from the wheel-side device
to the body-side device and registered in the body-side device. The apparatus assists
the system so as to automate the registration of the wheel identification data,
thereby eliminating a manual operation to bring a trigger device to the positions
of the wheels to command the wheel-side devices to transmit the wheel identification data.
