Harris Corporation

Textron Innovations Inc.

Greenlee Textron Inc.

Thomas W Durston

Steven R Coffelt

Richard W Faith

Wayne K Wong

Theodore E Chavannes

Robert G Crick

James D Eckman

George D Fleitz

The test instrument is used to perform both time domain reflectometry (TDR) and analysis of transmission signals on a line under test. Further, the test instrument provides for both pulse TDR and step TDR. A coupling transformer having an enhanced low frequency response provides for coupling of the test instrument to the line under test. Isolation circuits between the coupling transformer and the line under test to prevent damage to the test instrument due to voltages on the line under test allow the test instrument to be used in connection with an active line under test. Two isolation circuits are utilized to maintain longitudinal balance of the circuit. During step TDR, the positive and negative transmitter circuits provide step-shaped impulse signals. The enhanced low frequency response of the coupling transformer allows for transmission of step-shaped impulses, including the DC components of those signals, to the line under test and allows for transmission of reflected signals, including the DC components of those signals to the receivers. The test instrument provides selectable impedance matching and provides for selectable attenuation levels.

Test instruments for pulse TDR, step TDR and transmission analysis

A bridge module provides connection between first and second conductors of a line under test and a test instrument adapted for use with the bridge module. The bridge module provides monitoring and measurement of DSL communication signals between the telephone company DSL terminal (DSLAM) and the subscriber home DSL equipment across a wide range of frequencies. The bridge module can be used at any point in the communications link and can be used while the link is active. The bridge module provides a clickless connection to the active DSL communications link to avoid interruption in DSL service.

Wideband high impedance bridging module

A device for measuring and isolating noise-creating imbalances in a paired telecommunications line has an internal circuit. The internal circuit includes a pulse generator. Pulses provided by the pulse generator are applied to an interface which includes balanced pathways to the conductors. The pulses are applied simplex (longitudinally) to the pair of conductors. Upon encountering a fault in the pair, a reflected metallic voltage signal is received by the interface. The reflected metallic voltage signal is sampled by an analog-to-digital converter. Data relating to the sampled signal is displayed for detection and location of faults on the pair.

Apparatus for detecting imbalances in a paired line

A D channel monitor is provided which is capable of providing a plurality of operating modes for monitoring D channel operation. As such, the D channel monitor can include first and second interface elements which can be operated to appear as either an NT interface (for a TE) or as a TE interface (for an NT). A controller is provided which can control the first and second interface elements to appear as predetermined ones of the NT interface or the TE interface for respectively coupling to either a TE or an NT of the ISDN user terminal. A monitoring arrangement is also included for monitoring the D channel signals at the terminal which are received through either of the first and second interface elements. This monitoring arrangement includes means for indicating the status of the D channel signals to a user.

D channel monitor

An integrated services digital network (ISDN) traffic generator adapter is provided for coupling an analog traffic generator which produces a plurality of commands and analog telephone signals to an ISDN switch. In particular, first circuits provide a plurality of two-way communication links between the analog traffic generator and the ISDN switch. Each of said first circuits includes elements for converting the analog telephone signals from the analog traffic generator into a plurality of ISDN signals, including B channel information and D channel information, for said ISDN switch, and elements for converting a plurality of ISDN signals from the ISDN switch, including B channel information and D channel information, into analog telephone signal for said analog traffic generator. A processor is coupled to the plurality of first circuits for selectively addressing individual ones of said plurality of first circuits. Also, a D channel monitor is coupled to the processor for monitoring D channel communication between the first circuits and the ISDN switch. The D channel monitor can selectively monitor D channel communication between the first circuits and the ISDN switch for individual two-way communication links between the analog traffic generator and the ISDN switch in accordance with the selection of one of the first circuits by the processor.

ISDN traffic generator adapter

The telephone line test capability of a craftsperson's test set is supplemented by communication/interface circuitry which carries out data communications with a host central office control processor, and contains memory for storing (task assignment) information downloaded from the central office control processor. This task assignment information stored in the test set-communications unit may be coupled from the unit to an associated printer for providing a hard copy of service assignment information to the field technician. In addition to printing out the downloaded task assignment information, the printer unit contains a charging circuit which charges a rechargeable battery in the handset for powering its internal circuitry. During off-duty hours, the test set may be connected to a home dispatch unit installed in the craftsperson's home and through which the handset is coupled to a telephone link for providing off-duty communications with the central office processor without technician intervention. The home dispatch unit also contains a battery charging circuit through which the test set's internal battery is charged when the test set is coupled to the dispatch unit and communications between the central office and the test set-communication unit are not taking place.

Test set communication/interface system

An improved telephone test unit is disclosed which permits the telephone line technician to selectively choose the audio reproduction of signals ocurring on the line without the use of the handset in the test unit. An auxiliary amplifier is provided to amplify the signals which are received from the telphone line. When the amplifier is activated, the transmitting unit and receiving unit of the handset within the telephone test unit are electronically muted to prevent undesirable audio feedback to the amplifier. The gain of the amplifier may be selectively varied between an off, low and a high gain condition. The amplifier is also usable in the 'monitor' condition of the telephone test unit.

Telephone test set having an auxiliary amplifier and speaker for

An improved telephone test set is disclosed which may be operated with low voltage line conditions. Transmitting and receiving voice communication circuits are connected in parallel with leads which are adapted to be connected to the tip and ring lines of a subscriber's telephone line to isolate the voice transmitting and receiving circuits from the voltage drop of a polarity guarding bridge which is connected to the signalling circuits of the telephone test set. A polarity indicating circuit to indicate the direction of current flow between the tip and ring lines of a subscriber's telephone line is connected in series with the voice transmitting and receiving circuits.

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Camarillo, CA, United States of America

Thomas W Durston