<p><it>Abstract—</it>Radoytchevsky and Shalaev in their correspondence claimed to find systems which are not $<tmath>t_{p}</tmath>$-diagnosable under the PMC model yet satisfy the conditions for $<tmath>t_{p}</tmath>$-diagnosable systems in a characterization given by Dahbura and Masson. In this reply, we explain why the authors are incorrect in their assertion.</p><p><it>Index Terms—</it>Connection assignment, diagnosable system, graph models, PMC model, syndrome, system-level diagnosis.</p>