A tail cap assembly for a light beam generator includes a jack, while a remote dual switch connected by a cable to a plug is removably connectable to the tail cap jack. A strobe latch section produces check data in synchronism with each of the delayed strobe signals, and a system latch section latches, with a system clock, check data latched by the strobe latch section. A first transistor of the pixel circuit outputs a current corresponding to the voltage charged in the capacitor. Information exchanged includes gateway attributes, link attributes, service availability, andor data availability. The conductor may be suitable for conveying electronic or spintronic or optical signals, and the coupling is more specifically a coupling to the fields associated with such signals.