The bus measuring box can be attached like the remaining system components over a 25-pin plug connector to the CAN function box. The CAN High and CAN Low of all CAN Systems, LIN comfort and LIN electrical system as well as the k-line over 3.5 mm of sockets are made by the box accessible. Thus fast and simply measurements with circuit analyzers and oscilloscopes are possible, without having to look for a long time for suitable measuring points in the circuits.