AUTOMATIC TOLL RECEIVING SYSTEM

摘要

PROBLEM TO BE SOLVED: To realize an automatic toll receiving system having a small-sized on-vehicle machine improving the selection accuracy of a transmission and reception frequency in an automatic toll receiving system that automatically receives toll without stopping a vehicle at a tollgate. SOLUTION: An on-vehicle machine can select a transmission and reception frequency used by a roadside machine on a traffic lane to which the vehicle is about to proceed as a result by comparing the output value of an AGC controlled voltage generating part 28 which is acquired when the frequency of a local signal generator 27 is set in accordance with a 1st transmission and reception frequency with the output value of the part 28 which is acquired when the frequency of the generator 27 is set in accordance with a 2nd transmission and reception frequency between the two kinds of transmission and reception frequencies that can be used by a previously recognizing roadside machine, and a small-sized on-vehicle machine can be realized without newly adding a circuit configuration detecting a received power level from the roadside machine to the on-vehicle machine.