A Simple and Efficient Bus System to Connect Single Units within a Satellite Laser Ranging System

Complex systems - like SLR (Satellite Laser Ranging) systems - often need a large amount of cables to connect all remotely controllable add-on units, like flip mirrors, servo-motors, switches etc. on different groups (like mount / telescopes, laser, control PC, observer control station etc.). At the Graz kHz SLR station, more than fifty separate cables connecting these groups have been replaced now with a few single BNC cables, using a simple serial bus system. Each single BNC cable completely connects 2 units (e.g. the PC and the mount); there is no need for synchronization or handshake signals. Data transmission speed ranges from very low - down to a single transmit only on request, or on any change of bits - up to 10 MBits/s. This serial bus is flexible, easy to extent for future upgrades, and fast.