Machinbird : thanks for the expanded curves, greatly interesting and informative.
Mr Optimistic :
could 'wrg' refer to a failure in message protocol rather than anything physical ?
Yes, indeed. I tend to incline towards software versions that could communicate very well under all normal circumstances but failed to do so under this very specific ADR-checking 10 seconds process. To be verified and pursued further, but I lack the relevant documents. Of course, software incompatibility is not part of the design assumptions, thus it could only appear as a "wiring" fault.