| 摘要 |
PURPOSE:To improve the reliability of transmitting signal by providing a deciding circuit to check the register to a main station by deciding that it is an error calling data when there are calls of a specific number or more in a specific time, and to register to the main station by deciding that it is a normal calling data when there are calls less than the specific number. CONSTITUTION:A deciding circuit 9 decides whether the number of calls is a specific number or more in a specific time or not from the calling data input from remote stations 2a-2n of the halls through a transmission line 10. When the number is the specific number or more, as a result, it is decided to be an error calling data and the register to a main station 1 is checked. On the other hand, when it is less than the specific number, it is decided to be a normal calling data, and the output signal from the deciding circuit 9 is delivered to register to the main station. In such a way, the reliability of transmitting signal against an external disturbance such as a noise can be improved, and the time of transmission can be reduced. |
