Status and activity monitor for contention type local area networks

Claim 1

In a cable connecting system connecting a first device to a second device with a cable carrying binary information between the first device and the second device over a wire contained in the cable, a self-contained, dual-purpose cable connecting device for connecting the cable to a device and for monitoring and visually indicating activity on the wire comprising: a) series connection means for inserting a connecting wire in series with the wire in the cable; b) signal sampling and triggering means connected to said connecting wire for sensing any binary signals on said connecting wire and for producing a trigger output when a binary signal is sensed; c) an illuminatable visible indicator; d) monostable device means having said trigger output connected to a monostable input thereof and a monostable output connected to said indicator for producing a signal at said monostable output of sufficient duration to illuminate said indicator for a visibly detectable period of time; and, e) means for deriving required power from a wire carrying power from the first device to the second device; wherein f) said signal sampling and triggering means include a high impedance means connected in parallel to said connecting wire, said high impedance means including prebiased semiconductor components whereby said signal sampling and triggering means interfaces to said connecting wire with an impedance sufficiently high to preserve the integrity of said binary information being carried in the wire.