A communication system having first and second states for use with a shared transmission line composed of at least two conductors and composed of first and second transmission line segments connected to each other at a single connection point. In the first state, a termination is coupled to the single connection point and is operative to at least attenuate a signal propagated between the first and second segments. In the second state, a driver is coupled to the connection point and is operative to conduct a signal over the first and second segments.