Abstract: The detection of an insulation fault on a network furnished with tappings by a first monitor can be followed by the location and identification of the fault by way of a locator to be placed on the tappings. To satisfy the level-two security, or SIL-2, in which the risk of occurrence of a hazard is decreased by a factor of greater than 100, second means for detecting the insulation fault are installed, to obtain a redundant item of information as regards the insulation resistance of the network, independently of the monitor but associated with a locator.

Abstract: A method of monitoring a device which is equipped with a microprocessor, which method includes computation in the microprocessor on input data; performing a logic operation by logic gates in an external monitoring device on the same input data; comparing the results of the computation and the logic operation, and deriving from the compared results a diagnostic of the microprocessor, and optionally then switching the microprocessor to a backup safety mode. A device for carrying out such monitoring is also described.

Abstract: The detection of an insulation fault on a network furnished with tappings by a first monitor can be followed by the location and identification of the fault by way of a locator to be placed on the tappings. To satisfy the level-two security, or SIL-2, in which the risk of occurrence of a hazard is decreased by a factor of greater than 100, second means for detecting the insulation fault are installed, to obtain a redundant item of information as regards the insulation resistance of the network, independently of the monitor but associated with a locator.

Abstract: A monitoring method of a device equipped with a microprocessor, comprising the following steps: performance of at least one computation in the microprocessor from input data; performance of at least one logic operation by logic gates in an external monitoring device from the same input data; comparison of the results of the at least one computation performed in the microprocessor and of the at least one logic operation performed in the monitoring device to deduce therefrom a diagnostic of the microprocessor and/or a command to switch to a safe configuration.