| 摘要 |
A security system for a vehicle, comprising a control unit (1), for processing control signals, and having at least a first state, indicative of normal operation of the vehicle, and a second state, indicative that the vehicle has been the subject of unauthorised interference, a radio transmitter (5) connected to the control unit, and adapted, on receipt of a first control signal from the control unit (1), to produce a first radio signal, indicative of unauthorised interference with the vehicle, means (2) for producing, on receipt of a second control signal from the control unit (1), a visual indication visible from outside the vehicle, or an audible indication audible from outside the vehicle, indicative of unauthorised interference with the vehicle, means (3) for immobilising the vehicle, on receipt of a third control signal from the control unit (1), means (7) for sensing unauthorised interference with the vehicle, and for producing an indication to the control unit (1) to switch the said control unit (1) to the said second state, on receipt thereof, means (8) for sensing whether or not the vehicle is active, means (1) for inhibiting production of the said third control signal when the vehicle is active, a radio receiver (4) adapted to receive an interrogation signal from an interrogator transmitter (10), means (1) for distinguishing different types of interrogation signals, and for producing a response which varies in dependence upon the type of interrogation signal received, wherein the control unit (1) is adapted to produce the said first, second, and third control signals only on receipt of a said interrogation signal. |
