Modbus Tcp; Introduction - Lenze i55AE125B Manual

Configuring the network

Modbus TCP

Introduction

9.8 Modbus TCP
Modbus is an internationally approved, asynchronous, serial communication protocol,
designed for commercial and industrial automation applications.
Detailed information on the Modbus can be found on the web page of the international
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Modbus Organization, USA, who also further develop the Modbus protocol: http://
www.modbus.org
Information about the dimensioning of a Modbus network can be found in the configura-
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tion document for the inverter.
Preconditions
Control unit (CU) of the inverter is equipped with Modbus TCP.
9.8.1 Introduction
The process of data transmission distinguishes between three different operating modes:
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Modbus ASCII, Modbus RTU and Modbus TCP/IP. This chapter describes the Modbus
TCP/IP operating mode.
The Modbus protocol is based on a master/slave architecture where the inverter always
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works as slave.
In the Modbus TCP/IP network, a master can only address one slave at a time. However,
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several masters can be available in the network.
Only a master can initiate the Modbus communication.
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No direct communication takes place between the slaves.
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The network option supports the baud rates 10 Mbps (10 BaseT) and 100 Mbps
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(100 BaseT). The baud rate in the network is automatically detected.
The inverter supports the function codes 3, 6, 16 (0x10) and 23 (0x17).
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