Gould Inc.

Modicon, Inc.

John J Finnegan

Salvatore R Provanzano

Lawrence W Hill

Wilbert H Aldrich

Michael C Nollet

Ronald D Malcolm

James Heom

Emil P Drottar

Michael B Tressler

Robert A D'Angelo

Kincade N Webb

Baruch S Perlman

David James Holigan

Paul Zdinak

George Harris

John E VanSchalkwyk

Anatoly V Fridland

John E Van Schalkwyk

The data communication capacity of an existing local area network (LAN) 10 that uses a shielded twisted wire pair 16 as its transmission medium may be increased with the addition of special frequency selective terminators 36 and single-ended transceivers 20. The single-ended transceivers 20 have two single-ended transmitter connections 42,44 to the two twisted wires 22,24 in the shielded twisted wire pair medium 16, respectively, and one single-ended receiver connection 46 to one of the two twisted wires 22,24 in the shielded twisted wire pair medium 16. The shielded twisted wire pair medium 16 is terminated by the special frequency selective terminators 36 which provide transmission line impedance matching over the signal bandwidth of a single-ended data channel, while providing a high impedance over the signal bandwidth of a differential data channel. Thus, differential data communications are allowed over the signal bandwidth of the differential data channel, while single-ended data communications are allowed over the signal bandwidth of the single-ended data channel, thereby increasing the overall data communication capacity of the LAN.

System for increasing the capacity of existing local area networks that

Programmable controller housing

An improved programmable controller having the ability to use two different data bases while presenting to the outside world a uniform word size. The programmable controller includes pipeline processing and hardware solution of a user control program in a network node format. A memory management scheme is provided allowing for the direct addressability of one-half million words by utilization of a page register. The programmable controller can be incorporated into a network containing other programmable controllers. The programmable controller also incorporates a multi-task interrupt so that the processor can handle more than one job at any particular time. Input/output tasks are handled logically in the scan solving the user networks rather than being based upon a particular physical area of the controller memory.

Programmable controller

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Hudson, NH, United States of America

John J Finnegan