| 摘要 |
<p>An analogue circuit or unit under test (34) is tested utilising automatic test equipment (30) and an interface unit (35) to apply stimuli to the circuit (34), the stimuli including supply potentials. A computer (32) analyses the circuit (34) as a network of nodes and modules to deduce a set of ranges of values at selected nodes, the ranges being determined from the set of the stimuli and a resultant set of test measurements, taken from nodes of the circuit by means of the interface (35) and automatic test equipment (30), taking into account tolerances in the stimuli, the measurements and the nominal parameters of components of the circuit. If there is inconsistency among the derived ranges the computer (32) treats as potentially faulty any module which could remove the inconsistency if the constraints imposed by that module were suspended. The computer (32) controls an iterative, hierarchical process involving repetition of the sequence of steps using different sets of stimuli and/or measurements and/or different analyses of the circuit into nodes and modules, in particular with analysis in terms of successively smaller modules. In this way, the location of faults can be progressively narrowed down and corresponding output information can be given in a device (40) such as a VDU or printer.</p> |
