Abstract: A novel and improved engine data system for collecting, displaying and analyzing engine/vehicle data is provided. The system have advantageously results in a more effective, convenient, portable and low cost method of monitoring and processing vehicle data. The vehicle data system includes a handheld computer containing operating system software adapted to operate the handheld computer in accordance with a data protocol different from a vehicle bus protocol and a handheld microprocessor for executing the operating system software. The system importantly includes an adapter for creating a data pathway between a vehicle bus connector and an external data port provided on the handheld computer which is physically incompatible with the engine bus connector.

Abstract: A novel and improved engine data system for collecting, displaying and analyzing engine/vehicle data is provided. The system have advantageously results in a more effective, convenient, portable and low cost method of monitoring and processing vehicle data. The vehicle data system includes a handheld computer containing operating system software adapted to operate the handheld computer in accordance with a data protocol different from a vehicle bus protocol and a handheld microprocessor for executing the operating system software. The system importantly includes an adapter for creating a data pathway between a vehicle bus connector and an external data port provided on the handheld computer which is physically incompatible with the engine bus connector.

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 microprocessor-controlled voltage source selectively provides to a telephone line either a DC or an AC voltage, prescribed characteristics of which are programmably adjustable, enabling test equipment to controllably condition and test the line with essentially any desired line conditioning voltage or signal waveform. A digital-to-analog converter (DAC) provides an output voltage having an amplitude that is digitally programmable. This output voltage is available to be applied either directly or through controlled amplifier circuitry to the line. In order to generate an AC signal having both an adjustable amplitude and waveform characteristic, the output of the DAC sets the amplitude for a combination of signals from a plurality of squarewave generators having programmable frequency characteristics. The output of the combining unit is coupled to a switched capacitor filter which filters the controllably-interrupted, digitally-controllable output voltage, (e.g.

Abstract: A signal processing circuit measures the phase difference between digitally formated reference tone and telephone line signals over a prescribed number of signal periods so as to provide to an attendant processor an average value of phase differential. The reference tone and line signals are conditioned as square wave signals, and applied to a first exclusive-OR circuit and to respective divide-by-two flip-flop circuits, which produce square wave signals having a frequency which is half the frequency of the conditioned square wave signals. The output of the first exclusive-OR circuit represents the half-cycle phase difference between the two sine waves. The full-cycle square wave signals are applied to a second exclusive-OR circuit, which produces a series of pulses, each representing a respective full-cycle phase difference between the reference and line sine waves.