Switching characteristics monitor for telecommunications exchange - repeatedly interrogates switching devices and successively compares results

摘要

The switching devices (X1, X2, X3) in a telecommunications exchange are repeatedly interrogated (D). This stabilises an interrogation result indicative of the state of an associated one of the switching characteristics used in the exchange. The interrogating device (D) stores the interrogation results and for each switching device detects each switching state transition in accordance with predetermined criteria from a comparison of consecutive interrogation results. The frequency of interrogation for a switching device, may be varied in dependence upon the comparison e.g. increased when switching state transitions indicated.