We present a methodology for model-based diagnosis of
analog circuits using the constraint logic
programming approach. Presented methodology stems from our earlier work
on the diagnosis of active analog filters by using $CLP(\Re)$
and has the following major improvements: modeling of
the diagnosed circuit is generalized to arbitrary analog circuits
consisting of linear elements (non-linear circuits are
included by piecewise linearisation of their characteristics);
both hard and parametric faults are considered in the diagnostic process;
fault situations with multiple-hard-and-single-parametric faults
can be diagnosed. Examples are given to illustrate the approach.
(reprints available on request)