| 摘要 |
PURPOSE:To monitor a tone signal inherent to an observation terminal station and to enable simultaneous communication between an observation center and an observation terminal station by providing a monitor connection control for monitoring a call signal and for connecting a lower opposite communication control and upper opposite communication control to a monitor connection control. CONSTITUTION:A system connects a center communication control part 34 at an observation center 3 to an upper opposite communication control part 62 at an observation subcenter 6 with a communication line 5 and connects observation terminal stations 1a-1n to the lower opposite communication control 61 by communication lines 4a-4n. The system connects a tone signal monitor connection parts 63 and an observation data file 23 betweend the upper and lower control parts 62 and 61 at the subcenter 6. This connection 63 monitors an inherent call signal from each of these terminal stations 1a-1n and connects between the upper and lower control parts 62 and 61. The control part 63 monitors an inherent call signal of each of these terminal stations 1a-1n from the center 6 and connects a terminal corresponding to the call signal to enable simultaneous communication between the center 6 and of these terminal stations 1a-1n. |
