Abstract: A process for controlling pneumatic servomotor of the type comprising a control by a motor jack supplied with pressurized fluid by a pressure modulator of said fluid and a first slaving loop causing said jack to slave in a given reference position, wherein each reference position is stored in analogue manner by movable mechanical friction means carrying said modulator and displaced by means of a second disengageable slaving loop which is substituted for the first during reference position changes and which takes its displacement energy for the movable mechanical means directly from the motor jack.

Abstract: Process for the automatic signalling of faults of an automatic static safety module and a module realizing said process which can be used in automatic safety systems which can, for example, be used in nuclear reactors.The module comprises at least one pair of identical parallel logic circuits each having a first positive continuous supply connection and a second negative supply connection. The circuit output can have one or other of two logic states depending on whether it is connected to the first or second connection. It comprises means for the automatic signalling of a fault in one module component constituted by a.c. voltage sources of different frequencies inserted in the supply connections. It also comprises means for detecting the presence of beats between the a.c. voltages appearing at the outputs of circuits and for indicating cases of non-agreement of the logic states.