A telecommunications circuit pairs identifier device that has a transmitter portion that is connected to a predetermined group of pairs at the trunk line termination point and a receiver that is plugged at each one of the jacks distributed in a given network. The transmitter continuously accesses each...http://www.google.es/patents/US4748402?utm_source=gb-gplus-sharePatente US4748402 - Circuit identifier tester for telecommunication pairs
Circuit identifier tester for telecommunication pairs
