Digital Equipment Corporation

James A Daly

Michael W Patrick

Gerald J Brand

James M Gregorich

Daniel L Belanger

An apparatus is provided for detecting the signaling frequency of communications signals transported on the trunk and lobe circuits of a token ring. The communications signals including Differentially Manchester Encoded data signals. The apparatus includes an internal trunk circuit and a plurality of ports including an input port for connecting to an input trunk segment, and an output port for connecting to an output trunk segment, and a plurality of lobe ports for connecting to the lobe circuits. Means are provided for sensing the frequency of the data signals at each of said plurality of ports. The sensing means including means for taking multiple successive timing samples, and grouping the samples into quality groups.

Signaling frequency detection for a communications network

An apparatus for establishing timing signals of a communications network includes a plurality of ports and an internal trunk circuit for interconnecting trunk segments and lobes of the network. A speed detection circuit connected to each of said plurality of ports, are provided for sensing a plurality of timing signals, there being one timing signals sensed at each of the plurality of ports. The apparatus establishes a timing signal on the internal trunk equal to the timing signal senses at a majority of the ports to enable a majority of the nodes connected to a majority of the plurality of lobe ports to transport communications signals via the network.

Configuration controller for establishing timing signals of a

An arrangement for a token ring communications network includes nodes for transmitting and receiving data signals. Also provided is a communications medium for transporting the data signals includes a trunk circuit having a plurality of trunk segments, each trunk segment having an input end and an output end and a plurality of lobe circuits for connecting the nodes to the trunk circuit. A plurality of wiring concentrator are provided for connecting adjacent trunk segments as a ring. Each wiring concentrator having a plurality of ports including an input port connected to an input end of one of the trunk segments, an output port connected to an output end of one of the trunk segments, and a lobe port connected to one of the lobe circuits. Each wiring concentrator includes an internal trunk, a controller, and a plurality of switches for interconnecting the ports while the voltage and the frequency of the data signal are within predetermined voltage and frequency ranges.

Arrangement for a token ring communications network

An apparatus for controlling configuration of a communications network, the network including a trunk having trunk segments and lobe circuits for connecting to nodes. The apparatus comprises an internal trunk circuit, and a plurality of ports. The ports include a lobe port for connecting to a lobe circuit, an input port for connecting to an input trunk segment, and an output port for connecting to an output trunk segment. State machines are provided for sensing the communications signal at a corresponding one of each of said plurality of ports. Each state machines is transitioned by a set of transition rules which include inputs from the sensed communications signals. The state machines enable the connection and disconnection of said ports to said internal trunk.

State machines for configuration of a communications network

A housing for batteries which may be combined with a battery charger in a mechanically integrated module. The module is mobile and includes a load-bearing frame, battery retaining members, and mechanical stabilizers. The base of the frame includes a raceway or channel for routing interconnecting wires between the charger assembly and batteries. The battery retaining members permit easy installation or removal of individual batteries from the housing as well as inhibiting lateral movement of the batteries within the housing. When the module is free-standing, the stabilizers deploy automatically for enhanced mechanical stability.

Modular housing for batteries and battery charger

An apparatus for controlling configuration of a communications network includes an internal ring segment for interconnecting a trunk circuit with lobe circuits of the network. The apparatus is provided with lobe ports for connecting to the lobe circuits, a ring input port for connecting to an upstream ring segment of the trunk, and an output port for connecting to a downstream ring segment, of the trunk. A plurality of trunk coupling units (TCUs) are provided, one for each port, for connecting a corresponding ports to the internal ring segment. Each of the TCUs has an inserted state to provide signaling continuity for the communications signals between a port and the ring segments, and each TCU has a wrapped state to provide signaling isolation between a port and the ring segments. A controller, responsive to the communications signals switches the TCUs between the wrapped and inserted states.

Configuration controller for a communications network

A power converter, based on a modular architecture, in which a boost power factor correction circuit is provided as an input stage for both a primary power source and a battery power source. This arrangement permits the same power conversion stages which follow the boost power factor correction circuit to be used regardless of whether the primary or battery power source is in use. The power supply includes a controller for monitoring the primary power source voltage and the DC voltage produced at the output of the boost circuit and comparing each to a preselected reference. When a sufficiently large difference appears between each of those voltages and its respective reference, the controller connects the battery power source to the input of the boost circuit and simultaneously disconnects the primary power source therefrom. This switching of power sources is transparent to the load whose input voltage is maintained at a substantially constant level by the boost power factor correction circuit.

Power converter with controller for switching between primary and

According to the invention a battery charger for charging a plurality of batteries includes a voltage supply connected by a pair of switches to a power converter including a transformer having a primary winding and a plurality of secondary windings. Each secondary winding is coupled to a battery. Voltage is transferred from the voltage supply to the primary winding when the switches are closed and current is transferred from the secondary windings to the batteries when the switches are open. Charge control circuitry monitors the voltage of each battery and the total battery voltage and determines the amount of current to supply to the batteries. Supervisory logic monitors the current received from the secondary windings by each of the batteries and the voltage of each of the batteries to determine the charge status of each battery and the operating status of the power converter. If one battery continues drawing a greater proportion of the maximum current relative to the remaining batteries after the predetermined voltage limit has been reached, this indicates that there is a short circuited cell causing one battery to draw a greater proportion of current or that there is a cell with high impedance causing one battery to draw a smaller proportion of current. For both fault conditions, the supervisory circuit detects the current imbalance and generates a shutdown signal. The shutdown signal is also asserted when the supervisory circuit detects an over voltage condition in any of the batteries, or an over current in the primary winding. The shutdown signal subsequently precludes further operation of the charge control circuit for a predetermined time period, alerting the system operator of a problem within the battery backup system, and avoiding the loss of vital information and expensive computing time by allowing for correction of the fault condition before damage results.

Fault detector for a plurality of batteries in battery backup systems

An isolation amplifier employs feedback to accurately amplify an input signal while maintaining electrical isolation between the input and output signals. The isolation amplifier consists of an amplitude modulator, an isolation transformer having a pair of matched secondary windings, a peak-detector output circuit, and a matching peak-detector feedback circuit. The isolation transformer couples an amplitude-modulated signal to both peak detector circuits while maintaining electrical isolation. The output from the feedback circuit is fed back to the amplitude modulator, so that the amplitude-modulated signal represents the difference between the input to the amplifier and the feedback signal.

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Chelsea, MA, United States of America

James A Daly