Communication; Smv800 Modbus Communication; Modbus Communication Overview; Physical Layer Requirements - Honeywell SMV800 User Manual

3.1

SMV800 Modbus Communication

This section contains the Modbus interface and register map used in SMV800 Modbus
transmitter. Use this section to locate the Modbus register for the process variable and
status bits that will be retrieved from the SMV800 Modbus. The purpose of including this
register map is to provide the information required to implement this register map within a
host to achieve an effective exchange of data with the SMV800 Modbus. It is expected that
anyone creating such an interface has thorough understanding of the Modbus protocol.
Reference the "Modicon Modbus Protocol Reference Guide PI-MBUS-300 revision
J"published by Modicon, Inc.,Industrial Automation System for further information.
3.2

Modbus Communication Overview

The SMV800 Modbus is a Modbus-compatible measurement device. The SMV800
Modbus supports standard Modbus RTU transmission mode.

3.2.1. Physical Layer Requirements


RS-485

2-wire

Half-duplex

3.2.2. Data Format


Data bits: 8 (Not Configurable)

Stop bits: 1 (Not Configurable)

Parity: Even, Odd, None (Configurable, default is None)

Bit Order: Least significant byte(LSB) (Not Configurable)
Revision 1.0

3. Communication

SMV800 Modbus User's Guide Page 105