A riveting system is operable to join two or more workplaces with a rivet. The antenna device includes attachment means with which the antenna can be temporarily attached, moved and securely attached to the vehicle body side. Each of a plurality of coefficients may be applied to a corresponding one of the signal taps to generate an equalized signal. Whenever the signal line is detected not to assume a predetermined state during a predetermined period of time, the recovery component causes a hardware reset of the hardware module.