Organization of this manual, Reference documents, Serial communications – Despatch Protocol 3 Modbus Communications User Manual
Page 6: Supported protocols, Rs485 configuration
A
BOUT
T
HIS
M
ANUAL
Modbus Programming Manual
6
Version 2
Copyright © 2012 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Global Headquarters
Contact
Service & Technical
Support
Despatch Industries
8860 207th Street
Lakeville, MN 55044
USA
International/Main: 1-952-469-5424
US toll free: 1-888-337-7282
Fax: 1-952-469-4513
[email protected]
www.despatch.com
Service: 1-952-469-8230
US toll free: 1-800-473-7373
Service @despatch.com
1.3. Organization of this Manual
This document provides all application-specific information necessary for developing a Modbus
Master application program for interfacing with the Protocol 3™ slave controller.
1.3.1. Reference Documents
The following Modbus Protocol documents should also be helpful and relevant:
For a complete description of the Modbus protocol refer to the description provided at
http://www.modicon.com/ or http://www.modbus.org/.
This programming manual assumes an intermediate
understanding of the Modbus Protocol. Only limited
information is presented here regarding the Modbus Protocol
specifications.
1.4. Serial Communications
1.4.1. Supported Protocols
The unit supports two communication interfaces Modbus RTU and Modbus TCP. Modbus RTU
is supported through the RS485 interface and Modbus TCP is supported through the optional
Ethernet Module.
For a complete description of the Modbus protocol refer to the description provided at
1.4.2. RS485 Configuration
The RS485 address, bit rate and character format are configured via the front panel from the
Comms Configuration menu.
Physical layer configuration settings possible are:
Data rate:
4800, 9600, 19200, 38400, 57600 or 115200 bps
Parity:
None (default), Even, Odd