Junctor checking system

摘要

A junctor checking system for an electronic PABX which checks the potential of the junctor under control of a microprocessor. A voltage level sensing circuit is connected to the junctor to be checked; a resistor connects the input of the voltage level sensing circuit to a voltage source. In the event the impedance of the junctor to ground is not as expected with respect to at least one threshold, the junctor is considered faulty and a different idle junctor is selected.