US Patent 8651878 I/O module

The present invention relates to an apparatus for connection between power transmission system field equipment and control and protection equipment and comprising at least one input/output module (24). The module (24) comprises a box (34) enclosing a circuit board with at least one signal handling unit, at least one bus connector (36, 38) that stretches through a first side of the box, and a set of terminal blocks (40) for connection of field wires to the field equipment, where the terminal blocks are placed on a second side of the box. The at least one signal handling unit includes at least one unit for conversion of input and output signals to and from the field equipment and bus communication according to a bus communication protocol.