| 摘要 |
PURPOSE:To monitor data for communication between terminal stations for both transmission and reception at a central monitor station in the lump, by using a duplexed transmission line in loop data highway. CONSTITUTION:The loop data highway consists of a central monitor station CTE and plural terminal stations RTE1-RTEn and is connected in a loop by an existing (N) system line and a spare (E) system line. Each remote terminal station transmits transmission data to the duplexed lines N, E at the same time on a designated channel on a frame of time division multiplex. Each terminal station selects and receives the data of either line based on the command of the central monitor station CTE. A monitor station monitors both the N and the E system lines so as to monitor selectively the line of a designated channel having monitor requests, thereby monitoring the transmission/reception of the data of communication between terminal stations in the lump. |
