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CONTENTS
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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 ............................................................................................................................... 2-35
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 .............................................................................................................. 3-14
