PURPOSE: To constitute the hub unit for executing line concentration/wiring of a trunk line and each data terminal, so that when a jumper or a partition is detected, it is obstructed that adverse effect spreads by executing automatically detachment and reconnection of its receiving port by a simple constitution, and also, the present state and the past state are discriminated by a flickering display and a lighting display and informed to an operator so as to be easily understandable.
CONSTITUTION: The hub unit is constituted by providing a hub control part 13 which is provided between a trunk line 2 and plural data terminals 3, and controls line concentration/wiring between each of them, and a transmission line monitoring control part 15 for monitoring a state in each receiving port of plural data terminals 3 subjected to line concentration/wiring by this hub control part 13, detaching the receiving port, when a partition is detected (in the receiving port, collisions exceeding a prescribed number of times are detected continuously or one collision exceeding a prescribed time is detected), and also, executing display control of an indicator 19 for a partition display of this data terminal 3.
KANEMOTO TETSUYA
KUNII NOBUTAKA
TAKAHASHI KAZUNORI
IIJIMA HIROSHIGE
TAKAHAGI HIROSHI
