COAXIAL TRANSMISSION LINE MONITOR SYSTEM FOR CATV

摘要

PURPOSE:To monitor a coaxial transmission line interconnecting a relay amplifier and a center equipment with inexpensive configuration by measuring a signal level of an incoming data signal generated from a terminal equipment at other terminal equipment. CONSTITUTION:When a relay amplifier 7 receives an incoming signal outputted from a down-stream relay amplifier, a high frequency modulation signal level measurement circuit 14 connected in parallel with an incoming signal amplifier 11 extracts a signal level of the incoming signal. The extracted incoming signal level is converted into a data signal by a control circuit 15 and sent as an incoming signal via an incoming data transmission circuit 13. The information of the incoming signal level sent to a coaxial transmission line 9 as the incoming signal is finally received by a reception circuit 5 of a center device 2 and inputted to a control computer 1 via an interface circuit 3. The state of the incoming transmission line between specific relay amplifiers is monitored at any time by the operation above.