Patent ID: 8316290

Claim:
A device for safe threshold-detection of state information from an analog signal, intended in particular for a railway type application, the device comprising: at least two acquisition diversity channels, each acquisition diversity channel including in series: a circuit for adapting the analog signal into a safe adapted continuous analog signal; and an unsafe channel threshold circuit able to supply channel state information comprising: a voltage source, the voltage source being temperature-stabilized over a predetermined temperature range and used as a voltage reference; an electronic analog-to-digital converter able to receive the safe adapted continuous analog signal as an input signal, and deliver a digital output signal sampling the input signal at a predetermined sampling frequency, and a comparison unit for comparing the digital output signal with a digital reference signal and able to supply channel output state information as a result of the comparison; the device for safe threshold-detection of state information from an analog signal further comprising: a fault detection circuit for detecting a fault, the fault detection circuit able to mutually compare the digital output signals of the analog-to-digital converters, and able to supply as a fault detection circuit output a consistency result, the consistency result being a function of the mutual comparison of the digital output signals; and a decision component able to determine safe detected state information at an output; the output of the decision component being a function of the consistency result supplied by the fault detection unit and of comparison results from the comparison units associated with the respective acquisition channels.