RFID tag for train wheels

摘要

A tag 12.1 for a vehicle comprises collar 32 adapted to be fitted on an axle of the vehicle. The collar carries an RF transponder 20.1 comprising transponder circuitry and an antenna 40. The circuitry is connected to a sensor 44 for a parameter associated with the assembly in use. The circuitry is responsive to cause the transponder to transmit a first radio frequency signal when a value of the parameter exceeds a threshold value.