Abstract: A distributed automation system comprising a programmable logic controller connected to programmable logic controllers equipped with a host unit and couplers communicating with the host unit through the back panel bus. One of the couplers is connected through a bus to associated equipment, wherein the coupler can communicate with the associated equipment through a server function using the TCP/IP protocol. The server coupler is provided with a mass memory containing (1) “PLC variables” type software objects that manage access to PLC variables, and (2) “manufacturer” type software objects that transform information from PLC variable objects to manufacturer-type information that can be used by the associated equipment.