| 摘要 |
PROBLEM TO BE SOLVED: To facilitate operation and to surely call the roll by eliminating radio interference between groups. SOLUTION: To each slave equipment 20, the group identification code of a group to which the slave equipment itself belongs, a slave equipment identification code characteristic to the slave equipment, and a characteristic time slot assigned to the slave equipment as a time till the sending of a response signal from the reception of a calling signal from a master equipment 10 are set. To the master equipment 10, the slave equipment identification code of each slave equipment 20 is registered. Then calling signals including the group identification code are simultaneously generated to each slave equipment 20 from the master equipment 10 and only when the group identification number is coincident, each slave equipment 20 receiving this calling signal sends the response signal including the slave equipment identification code in accordance with the characteristic time slot assigned to the slave equipment. Then the side of the master equipment collates the slave equipment identification code with the slave equipment identification code registered in advance to display a slave equipment left as mismatch on a display 14. |
