Abstract: A resistive fault condition detector for conducting one or more tests of a circuit to detect a resistive fault condition. The detector includes means for determining changes in current through a load during the test, and means for measuring changes in first and second voltages respectively between the circuit's live and neutral conductors and between the circuit's neutral and ground conductors during the test, the changes in the first and second voltages corresponding to the changes in the current respectively. The detector also includes means for calculating apparent source impedances for the live and neutral conductors respectively, based on the changes in current and the measured changes in the first and second voltages respectively, and means for calculating an estimated source impedance for each of the live and neutral conductors for the test.

Abstract: A resistive fault condition detector for conducting one or more tests of a circuit to detect a resistive fault condition. The detector includes means for determining changes in current through a load during the test, and means for measuring changes in first and second voltages respectively between the circuit's live and neutral conductors and between the circuit's neutral and ground conductors during the test, the changes in the first and second voltages corresponding to the changes in the current respectively. The detector also includes means for calculating apparent source impedances for the live and neutral conductors respectively, based on the changes in current and the measured changes in the first and second voltages respectively, and means for calculating an estimated source impedance for each of the live and neutral conductors for the test.

Abstract: A portable test meter is disclosed for measuring, calculating, recording and monitoring significant system parameters for a local communication network of the type used in industrial automation applications. The meter is disclosed in the context of a network employing the DeviceNet protocol. For each network parameter of interest, a rotary switch selects a desired one for display. An auto search mode selectable by the operator, increments through selected network parameters and compares measured or calculated values against stored data representing acceptable, marginal, or unacceptable conditions, and an associated visual indicia is displayed for each unacceptable or margin condition detected.

Abstract: A portable test meter is disclosed for measuring, calculating, recording and monitoring significant system parameters for a local communication network of the type used in industrial automation applications. The meter is disclosed in the context of a network employing the DeviceNet protocol. For each network parameter of interest, a rotary switch selects a desired one for display. An auto search mode selectable by the operator, increments through selected network parameters and compares measured or calculated values against stored data representing acceptable, marginal, or unacceptable conditions, and an associated visual indicia is displayed for each unacceptable or margin condition detected.