Abstract: The data line card printed board assembly provides an interface between a switching system and data terminal equipment operating in a selected one of a synchronous mode, an asynchronous mode and a synchronous polled mode and at a selected one of a plurality of different data rates. This assembly comprises a first arrangement coupled to the switching system to provide a first bidirectional communication path between the switching system and the data line card and a second arrangement coupled to the first arrangement and the data terminal equipment to provide the first bidirectional communication path between the first of the data terminal equipment and the data line card card. A computer arrangement diposed on the printed board assembly is coupled to the first and second arrangement for bidirectional control thereof to accommodate the selected one of the modes and the selected one of the plurality of different data rates.