Abstract: A processor-controlled integrated telephone line measurement and conditioning apparatus installable at a remote site provides a multiplicity of measurement and conditioning functions that are selectively executable in response to commands issued from a supervisory command site. The dual measurement and conditioning capabilities of the architecture of the present invention impart both remote measurement unit (RMU) functionality and metallic access unit (MAU) functionality that may be individually accessed and controlled. The RMU operates primarily as a test head that performs mechanized loop testing (MLT) tasks, while the MAU is operative to impart prescribed electrical conditions to a specified line circuit. When controllably accessed to operate as an RMU, the present invention responds to instructions from a command site (loop maintenance operations systems) and performs single-line demand tests on a line provided by a pair gain system.

Abstract: A self diagnostic test routine resident in firmware in a remote, programmable device for testing telephone lines diagnostically examines the operational capability of each of a plurality of prescribed signal processing functions contained within the test device, on a selected one of a `loop` (effectively continuous) basis, `automatically`--at a less than continuous but still meaningfully periodic rate, or `on-demand`--at any time requested by the user. In addition, a running log is maintained of the results of each diagnostic test, and the results of each diagnostic test are compared with a set of thresholds associated with respectively different standards of performance of the test device. As a result of this comparison, the performance capability or status of the device is classified into one of three categories: PASS, MARGINAL, or FAIL, and communicated to system maintenance personnel.

Abstract: A remote test unit for testing and conditioning one or more telephone lines includes multiple electronically erasable flash memory banks, which contain respective versions of the operating system employed by the test unit's micro-controller. An operating system modification routine employed by the host processor of a remote site allows the functionality of the remote test unit to be selectively modified by electronically installing an upgraded or downgraded version of the operating system, or by electronically selectively activating or deactivating one or more operational features of the currently active operating system.

Abstract: A remote measurement unit for testing and conditioning one or more telephone lines includes multiple electronically erasable flash memory banks, which contain respective versions of the operating system employed by the test unit's micro-controller. An operating system modification routine employed by the host processor of a remote site allows the functionality of the remote test unit to be selectively modified by electronically installing an upgraded or downgraded version of the operating system, or by electronically selectively activating or deactivating one or more operational features of the currently active operating system. A reset routine ensures that the operating system modification mechanism will only boot up the `correct` one of the two quasi-redundant systems available to the RMU's microcontroller after a system modification has been performed.

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.