| 摘要 |
PROBLEM TO BE SOLVED: To measure a communication range and install and adjust a roadside antenna in a short time or by a small staff. SOLUTION: A maintenance sequence for communication range measurement is communicated between an antenna controller 3 and an on-vehicle machine 2 through the roadside antenna 1 and the on-vehicle machine 2 when receiving a maintenance command stops a timer for recommunication inhibiting and enbles a continuous communication. When a communication is established in two ways between the antenna controller 3 and on-vehicle machine 2, buzzers 5, 5A and 7 are made to sound to indicate that the communication is normal. Consequently, a small staff is able to measure the communication range and install and adjust the roadside antenna 1 in a short time. |
