Embodiments of the present disclosure provide methods and apparatus for configuring additional CPICHs, e. The apparatus comprises: a soft magnetizable sheet, having an outer surface arranged to face the article in use, and an opposing interior surface; and a permanent magnet, shaped such that its magnetic field contains perturbations giving rise to indicia. Sense signal lines are manufactured such that at some point they are in close proximity to a signal trace which is to be monitored. Each co-occurrence pattern is mapped to different subsets of elements of an input signal. The hypothetical recognized component list is displayed with confidence levels at the remote center for selective checking by a human data center operator.