| 摘要 |
PURPOSE:To detect an erroneous connection by allotting a specific pilot frequency to a transmitting subscriber and detecting the reception frequency at the connected station of the remote side. CONSTITUTION:For connection between subscribers A1 and B1, a switching command is given to A and B stations respectively from a remote controller 1. At the same time, a command is given to the station B to detect a specific pilot signal frequency f1 of the subscriber A1. Then a switch contact is closed to form a path between subscribers A1 and B1. In this case, the pilot signal of frequency f1 is transmitted to the station A and a correct connection of path between subscribers A1 and B1 is confirmed at the terminal of the subscriber B1 of the station B as long as the pilot signal received after detection has a frequency f1. Otherwise a wrong connection is confirmed if the received pilot signal has no frequency f1. |
