Abstract: The rate of change of a metallic subscriber loop charging characteristic and the period of time elapsed subsequent to the coupling of testing circuitry of a remote test unit coupled to the line are measured. The operation of the testing circuitry within the remote test unit is initiated in response to the rate of change of line voltage reaching a preselected rate of change, prior to the elapsed period of time reaching a prescribed time value. If the measured period of time reaches a prescribed value prior to the monitored rate of change of line voltage reaching the preselected rate of change, the last sampled value of the line voltage is stored and reported to a mechanized loop test system supervisory site.

Abstract: A remotely controlled line conditioning apparatus is installed in the terminal where access to the telephone loop to be tested is readily available. Although a metallic bypass pair from the central office to the (remote) terminal may also be available, its presence and/or condition does not affect the ability of the apparatus to condition the line under test. The line conditioning apparatus includes a telephone line termination unit and an intelligent control unit. The telephone line termination unit has a telephone line access port to which a telephone line pair is selectively coupled, and is operative to controllably impart a selected one of a plurality of electrical signalling conditions to the telephone line pair under test. The control unit has a communication modem through which communication signals containing telephone line conditioning messages are coupled to and from the central office/remote terminal communication link.

Abstract: A direct access test unit for enabling a craftsperson at a telephone facility remote with respect to a central office to test subscriber lines comprises a first access port coupled to an access line circuit, by way of which the remote telephone facility communicates with the telephone office in the course of testing subscriber lines, and a second access port coupled to a test trunk circuit by way of which a subscriber line is to be tested by the test unit.