METHOD FOR DEFECT LOCALISATION AND ASSESSMENT IN DIGITAL UNIT Russian patent published in 2011 - IPC G01R31/28 

FIELD: electricity.

SUBSTANCE: while having digital units in service, defect statistics is collected. The collected data are used to determine rates of all possible defects for each group of identical digital units. A regular diagnosing of the digital block with using its circuit diagram and the Boolean function theory, is combined with creation of an analytical reference copy of the unit. During diagnosing of the digital unit, a program-controlled defect selected from a set of possible ones is modelled sequentially. The defect selection sequence is determined by its rate starting from the greatest value. For each modelled defect, pseudo-random multidigit code sets are formed. They are supplied simultaneously on both inputs of the diagnosed digital block, and its analytical reference copy on outputs of which responses are registered and compared. If the responses have coincided, the control is stopped, and the defect place and character of the modelled analytical reference copy shows the defect place and character in the diagnosed digital unit. Then defect rate statistics data are specified.

EFFECT: reduced diagnosing time.