The object of the invention is an automation data communications network (3-1, 4-1) comprising a control and data acquisition device (3-2, 4-2), said device supporting a protocol for controlling communications within said network (3-1, 4-1), and one or more IEDs (4-8 . . . 4-16), said device supporting a protocol for controlling communications within said network (3-1, 4-1) and including a switch (4-8a) with at least two ports arranged in a functional connection with the device. The invention is characterized in that an element (4-6) with at least two ports is arranged in a functional connection with the control and data acquisition device (3-2, 4-2) and that a first loop is arranged between the IEDs (4-8 . . . 4-16) and a second loop is arranged between the IEDs (4-8 . . . 4-16) and the control and data acquisition device (3-2, 4-2).