The invention relates to a mounting rail bus system (1) having a mounting rail (2) and a station bus (3) that is disposed in the mounting rail (2) and that comprises at least two connectable bus elements (6) for connecting to one associated module (4) each as a bus subscriber, wherein each bus element (6) comprises contact pins (21) for transferring electrical supply power and at least one circuit board (22) having conductors (23) for transferring electrical data and/or control signals of lower power than the supply power, and/or each contact pin (21) and each conductor (23) of the circuit board (22) is connected to one double busing contact element (30) each.
