US Patent 10296483 Fieldbus network with two-wire loop

A fieldbus coupler for coupling a local fieldbus network utilizing a first fieldbus protocol to a foreign field device or foreign fieldbus network through an interconnecting wired or wireless network transmission line that utilizes a second fieldbus protocol different from the first fieldbus protocol includes a first circuit configured to communicate over the local fieldbus network using the first fieldbus protocol, a second circuit configured to connect the fieldbus coupler with the interconnecting network transmission line and communicate over the interconnecting network transmission line using the second fieldbus protocol, and a third circuit configured to communicate with the first and second circuits and capable of transmitting data to and from the first and second circuits to enable communications between the local fieldbus network via the interconnecting network transmission line.