Square D Company

Mark S Weber

Brian T Hill

David J Sackmann

Joseph T Bronikowski

David K Johnson

A system allows for transferring messages between microprocessor based devices, such as programmable logic controllers (PLC), and a host computer over an Ethernet communications network. At the host computer level, these messages can be directed globally or locally. The host computer can immediately obtain messages from a programmable logic controller without interruption of the execution of the PLC's ladder program. The host computer can also receive unsolicited messages from the PLC.

System for sharing data between microprocessor based devices

A control system contains a communications network, a host computer and a programmable logic controller (PLC). The host computer includes prioritized alarm queues for receiving prioritized alarms from the programmable logic controller. Alarms fall into either a local or a global category, and each category supports three types of alarms: warnings, alerts or faults.

System for processing and prioritizing alarms from devices on data

A control system allows for transferring messages between a programmable logic controller and a host computer over an Ethernet communications network. The messages include a routing address specifying an originating drop number, a destination drop number, and a routing drop number. The system is responsive to the routing address for transferring the messages between the programmable logic controller and the host computer. The host computer can immediately obtain messages from a programmable logic controller without interruption of the execution of its ladder program. The host computer can also receive unsolicited messages from the programmable logic controller.

Apparatus for networking programmable logic controllers to host computers

A control system allows for transferring messages between a programmable logic controller and a host computer over a serial data communications network. The programmable logic controller executes a ladder program and has an integral network interface module for permitting direct communicative coupling to the communications network. Messages can be received and sent by the programmable logic controller without interruption of the execution of the ladder program. The programmable logic controller can receive unsolicited messages from the host computer.

LAN interface which permits a host computer to obtain data without

A transfer network interface module provides a communication link between a data communications network bus connecting a plurality of processor based devices and a redundant processing system. The redundant processor system has first and second processor based devices communicatively coupled to at least one other remote based device by means of the data communication network. The first processor based device operates on an active status and the second processor based device operates on a backup status until a switch occurs. The switch causes the second processor based device to begin operation on active status. The transfer network interface device is communicatively disposed between the first and second processor based devices and the data communications network and permits continuous communication between either of the first and second processor based devices and the remote processor based device regardless of which of the first and second processor based devices is on active status. Each transfer network interface module has a thumbmwheel switch for setting a unique address and a mutually common address on the data communications network.

Transfer network interface

A high speed control system allows for transferring messages between a programmable logic controller and a host computer over an Ethernet communications network. The host computer includes prioritized alarm queues for receiving prioritized alarms from the programmable logic controller. Alarms fall into either a local or a global category, and each category supports three types of alarms: warnings, alerts or faults. The system is responsive to the routing address for transferring the messages between the programmable logic controller and the host computer. The host computer can immediately obtain messages from a programmable logic controller without interruption of the execution of its ladder program. The host computer can also receive unsolicited messages from the programmable logic controller. The programmable logic controller can communicate with tasks within the host computer as though those tasks were other programmable logic controllers.

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Germantown, WI, United States of America

Mark S Weber