| 摘要 |
PURPOSE:To prevent unauthorized communication between a center device and a remote terminal, by attaching a group number at every building group at under control, transmitting the number and a building number at the time of communicating a supervisory control content in advance mutually, and collating the numbers at the center and the re mote terminal. CONSTITUTION:A telephone number storage part 11 and a group number storage part 12 attached at every building number are provided, and also, a transmission part 16 which couples the building number and the group number and transmits it to the remote terminal is provided at the center device. Also, a building number setting part 20 and a group number setting part 21 are provided, and a collating part 22 which decodes and collates the building number and the group number transmitted from the center device by the outputs of both setting parts 20 and 21 is provided at the remote terminal. And the remote terminal decodes and collates the building number and the group number transmitted from the center device by the building number and a group number setting output set in advance, and normal communication is performed between the center device and a prescribed remote terminal when a correct result is obtained.
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