Browse Prior Art Database

Centralized Control of a Distributed System

IP.com Disclosure Number: IPCOM000040064D
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Caraballo, JF: AUTHOR [+5]

Abstract

This article describes a technique for control/monitor of a distributed system from one point wherein all operations are centralized into two controllers. (Image Omitted) The automatic packaging and palletizing system (APPS) consists of a group of Personal Computers (PCs) communicating over a local area network (LAN), as illustrated in Fig. 1. Each computer is responsible for monitoring and controlling a section/zone of the manufacturing line, as shown in Fig. 2. Because of the fact that the zone controllers are spread throughout the area, it is difficult for one operator to manage the entire line. The technique described herein resolves this in that all the control/monitoring operations are centralized in two controllers. The two controllers involved are the APPS area controller and the APPS audit trail.

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Centralized Control of a Distributed System

This article describes a technique for control/monitor of a distributed system from one point wherein all operations are centralized into two controllers.

(Image Omitted)

The automatic packaging and palletizing system (APPS) consists of a group of Personal Computers (PCs) communicating over a local area network (LAN), as illustrated in Fig. 1. Each computer is responsible for monitoring and controlling a section/zone of the manufacturing line, as shown in Fig. 2. Because of the fact that the zone controllers are spread throughout the area, it is difficult for one operator to manage the entire line. The technique described herein resolves this in that all the control/monitoring operations are centralized in two controllers. The two controllers involved are the APPS area controller and the APPS audit trail. The APPS area controller maintains the current status of each individual zone controller on the LAN and has capability of altering their status. The APPS audit trail maintains/displays a log of all manufacturing line failures, zone controller failures and LAN failures. To maintain the current status of each zone controller, the APPS area controller broadcasts a NULL message (string of blanks) on the LAN every five seconds. When a zone controller on the LAN receives this NULL message, it automatically responds with another NULL message. The packet that contains the messages being transmitted on the LAN contains other parameters including the source and the destination of the transmission. With this response the APPS area controller now updates its screen to show the status of both the zone controller and the area it is operating as follows: Zone 1 Normal Online Zone 2 Normal Online Zone 3 Offline Zone 4 Normal Online Zone 5 Halt Online Possible states for each zone are as follows: 1- Off-line - not responding v...