A fluid power controller device comprises a plurality of valve modules arranged sequentially in a row direction and collected together as an array-like unit, such modules comprising respectively a principal valve having at least one moving valve member and at least one electrically operated valve drive for the principal valve. At least two of the valve modules placed sequentially in the row direction are spaced from each other with the formation of an intermediate space. In such intermediate space a diagnostic module is placed for the detection of at least one operational state of one or both principal valves.