tailieunhanh - Modicon Modbus Protocol Reference Guide

This guide is written for the person who will use Modicon Modbus protocols and messages for communication in Modicon programmable controller describes how messages are constructed, and how transactions take place using Modbus protocol. This guide should be used in conjunction with Modicon user guides for the types of networks and programmable controllers present in the application. Familiarity with your network layout, and with your control application, is assumed. | Modicon Modbus Protocol Reference Guide PI-MBUS-300 Rev. J I Modicon Modbus Protocol Reference Guide PI-MBUS-300 Rev. J June 1996 MODICON Inc. Industrial Automation Systems One High Street North Andover Massachusetts 01845 Preface This guide is written for the person who will use Modicon Modbus protocols and messages for communication in Modicon programmable controller applications. It describes how messages are constructed and how transactions take place using Modbus protocol. This guide should be used in conjunction with Modicon user guides for the types of networks and programmable controllers present in the application. Familiarity with your network layout and with your control application is assumed. The data and illustrations in this book are not binding. We reserve the right to modify our products in line with our policy of continuous product improvement. Information in this document is subject to change without notice and should not be construed as a commitment by Modicon Inc. Industrial Automation Systems. Modicon Inc. assumes no responsibility for any errors that may appear in this document. If you have any suggestions for improvements or have found any errors in this publication please notify us. No part of this document may be reproduced in any form or by any means electronic or mechanical without the express written permission of Modicon Inc. Industrial Automation Systems. All rights reserved. The following are trademarks of Modicon Inc. Modbus 984 ModConnect BM85 Modcom BP85 P190 SM85 RR85 SQ85 SA85 DEC is a registered trademark of Digital Equipment Corporation. VAX and DECNET are trademarks of Digital Equipment Corporation. IBM is a registered trademark of International Business Machines Corporation. IBM AT IBM XT Micro Channel and Personal System 2 are trademarks of International Business Machines Corporation. Microsoft and MS DOS are registered trademarks of Microsoft Corporation. Western Digital is a registered trademark of Western Digital .