| 摘要 |
PURPOSE:To perform accurate remote monitor without the monitor signal interferred with electromagnetic waves from other stations, by transmitting the monitor signal from a repeater station to a master station after locking other stations. CONSTITUTION:When a status change is produced to monitored items in a repeater station 2, the repeater station transmits a callout signal 5. When a master station 1 receives the signal 5, it transmits a lock signal 6 to all terminal stations 31-3n and 41-4n, to inhibit the transmission of electromagnetic waves from the stations. The repeater station 2 confirms by reception of the lock signal 6 that the terminal stations 31-3n are locked, and transmits a monitor signal 7 and an end of call signal 8 to the master station 1 succeedingly. Further, when the master station 1 receives the end of call signal 8, a release signal 9 is transmitted to release the lock state of the terminal stations 31-3n and 41-4n an to release the lines. |
