A centralised automation system for an irrigation system is disclosed that is associable with a local computer network of standard type with a standard network protocol of a building in a so-called "building automation" context. The automation system comprises a field control unit (4) for receiving, storing and issuing irrigation commands according to preset programs. The field control unit (4) is inserted into the building and interfaced with the local computer network (3) of the building in such a way as to communicate therewith by means of a dedicated protocol (EPRAS) based on a standard network protocol (TCP/IP). For each irrigable field sector there is provided a respective field bus (6) that acts as a transmission support with standard field protocol (ModBus) for communicating irrigation commands to a respective control unit (7) for solenoid valves (9). A respective protocol-translation bridge unit (12) enables the field bus (6) to be interfaced with the local computer network (3) (Fig. 1).
