Communication equipment, which performs the function of distributing and amplifying the control bus signal to 4 outputs of the C2200 substation, in installations that require it due to their peculiarity (up to 3 in cascade). The extension of the control bus is carried out using fiber optics, requiring two devices for the connection (one as a transmitter and the other as a receiver). It allows the bus to be extended to another D204F module to a maximum of 2,000 m, using a pair of multimode fibers (850 Nm - 62.5/125) with ST connectors. The fiber connection is indicated for reasons of distance and/or isolation from electrical disturbances on the bus. Each module can distribute the control bus into four copper branches, called Bus1 to Bus4, of 600 m each. 12V DC power supply (30 mA). Led indicators for diagnosis during start-up. Connection using plug-in strips (for 1.5 mm2 cable). Dimensions 101 x 105.5 x 24 mm, anchoring via DIN rail (35 mm symmetrical). Weight 133.3 g. Temperature range -10 to 55ºC, relative humidity without condensation < 93%.