Communication system, converter for use therein and method of signalling

Abstract

A communication system comprises first and second devices (2,3) having respective housings (5,6); a data trans-mission line (8) for transmitting data between the devices in a reflective signalling format; and conversion means (4) connectable to the line externally of the housings (5,6) for converting data between a reflective signalling format and another format. A method of signalling between first and second devices (2,3) linked by a transmission line (8) and of sensing a security violation of the line (8) comprises the steps of (a) transmitting a signal from the first device to the second device, reflecting the signal back to the first device in a manner corresponding to a first bit sequence, receiving the signal thus reflected at the first device, and comparing this signal with the transmitted signal to determine whether there has been a security violation of the line and to extract the first bit sequence.

Dependencies are inferred from the claim text.