A system for coupling an avionics component to a bus includes a junction box electrically coupled to the avionics component and to the bus. A circuit card disposed in the junction box includes a plurality of sockets. The some of the sockets are electrically connected to the bus. Others of the sockets are electrically connected to the avionics component. A modular network bus coupler is mountable to the circuit card. The bus coupler includes a housing with electrical isolation circuitry disposed therein. A plurality of pins are disposed exterior of the housing and engageable with at least some of the sockets of the circuit card. At least some of the pins are electrically coupled to the electrical isolation circuitry.