Route surveillance system

Claim 1

A system for surveying traffic along a route, comprising: a series of sensors fixedly disposed along said route, each of said sensors having an operating range limited to a route section respectively assigned thereto, the route sections assigned to said series of sensors sequentially adjoining one another; normally inactive monitoring means in each sensor triggerable into an active condition for emitting an output signal in the presence of a vehicle in the assigned route section; a control post including a source of recurrent start pulses and indicator means for the output signals of said sensors; a first two-way signal link between said control post and the first sensor in the series for transmitting said start pulses to said monitoring means thereof to trigger same into said active condition and for delivering an output signal therefrom to said indicator means; a further two-way signal link between each preceding sensor and the immediately following sensor in the series for transmitting trigger pulses to the monitoring means of said immediately following sensor to activate same and for delivering an output signal therefrom to the immediately preceding sensor for retransmission to said indicator means by way of all intervening sensors; and pulse-generating means in each preceding sensor for producing an outgoing trigger pulse for the immediately succeeding sensor in response to an incoming trigger pulse from said control post in the case of said first sensor and from preceding sensors in all other instances.

Claim 2

A system for surveying traffic along a route, comprising: a series of sensors fixedly disposed along said route, each of said sensors having an operating range limited to a route section respectively assigned thereto, the route sections assigned to said series of sensors sequentially adjoining one another; normally inactive monitoring means in each sensor triggerable into an active condition for emitting an output signal in the presence of a vehicle in the assigned route section; a control post including a source of recurrent start pulses and indicator means for the output signals of said sensors; a first two-way signal link between said control post and the first sensor in the series for transmitting said start pulses to said monitoring means thereof to trigger same into said active condition and for delivering an output signal therefrom to said indicator means; a further two-way signal link between each preceding sensor and the immediately following sensor in the series for transmitting trigger pulses to the monitoring means of said immediately following sensor to activate same and for delivering an output signal therefrom to the immediately preceding sensor for retransmission to said indicator means by way of all intervening sensors; and pulse-generating means in each preceding sensor for producing an outgoing trigger pulse for the immediately succeeding sensor in response to an incoming trigger pulse from said control post in the case of said first sensor and from preceding sensors in all other instances.