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CONTENTS
1
Introduction..................................................................................................1-1
1.1 About communication protocols............................................................................................................1-1
1.2 Outline of Ethernet communication functions........................................................................................1-1
1.3 RS-485 (option).....................................................................................................................................1-1
1.4 Preparation ...........................................................................................................................................1-1
1.5 Modbus RTU protocol...........................................................................................................................1-2
1.6 Modbus TCP protocol...........................................................................................................................1-2
1.7 Addition of new items and map version ................................................................................................1-2
1.8 Types of communication connection structures....................................................................................1-3
2
READ AND WRITE OF DATA.......................................................................2-1
2.1 Communication Protocol (Modbus TCP or Modbus RTU) ....................................................................2-1
2.2 Function code .......................................................................................................................................2-1
2.3 Error Response.....................................................................................................................................2-2
2.4 Reading of input register area...............................................................................................................2-3
2.5 Read and write of holding register area................................................................................................2-16
2.6 Other setting range...............................................................................................................................2-33
3
Modbus master function..............................................................................3-1
3.1 Overview...............................................................................................................................................3-1
3.2 Procedure of the recording data from slave devices...........................................................................3-3
3.3 Enabling the Modbus master function...................................................................................................3-5
3.4 Setting Modbus1 (RS485 communication setting, timeout, etc.)...........................................................3-7
3.5 Setting Modbus2 (communication type)................................................................................................3-8
3.6 Setting the Modbus master...................................................................................................................3-10
3.7 Checking the communication status of the Modbus master..................................................................3-12
3.8 Setting of calculating channels..............................................................................................................3-13
