Coupling apparatus for the connection of devices to a bus system

A coupling apparatus for the connection of devices (16, 17, 18) such as sensors, actuators, contact free protection devices (electro-sensitive equipment—ESPE), light barriers or controls to a bus system (1), comprising at least one connection unit (23) at the bus side for the connection of the coupling apparatus (22, 22′) to the bus system (1) and comprising at least one connection unit (26, 26′) for the connection of a device (16, 17, 18) to the coupling apparatus (22, 22′), with the connection unit (23) at the device side including n (n>1) contact elements (37-32, 39-43) of which each has one predefined functional property from a set of m (m>1) pre-defined functional properties (A, B, C, D),

• characterized in that at least some of the contact elements are made as variable contact elements (27-30, 39-42) to each of which one of the pre-defined functional properties (A, B,C, D) can be variably assigned.