| 摘要 |
<p>The frequency-coding system enables an output (S1-Sn) to be connected to a frequency generator (12) (non-secure state of the output), solely when in the absence of any fault in the system, the inputs (I1-In) associated with the output and supplied by a self- testable logic circuit, are in the high logic state. In each branch of the system, at least two interrupters (T1 and T2) must be operated simultaneously to allow connection between the corresponding output and the frequency generator. A simple fault in the system does not modify the behaviour thereof or produce a secure output signal, and a fault detector, comprising a test-vector generator (40) and a signature analyser (48), detects any fault, the combination of which with another fault would be liable to produce a non-secure erroneous output signal. <IMAGE></p> |
