Ebyte E90-DTU User Manual page 3

Chengdu Ebyte Electronic Technology Co., Ltd.
Chapter 6 Modbus Protocol Description ......................................................................................................................26
6.1 Introduction to Modbus RTU protocol ...............................................................................................................26
6.1.1 Communication format ............................................................................................................................... 26
6.1.2 Communication information transmission process .....................................................................................26
6.1.3 Address code ................................................................................................................................................26
6.1.4 Function code .............................................................................................................................................. 26
6.1.5 Function code 01H: read coil ...................................................................................................................... 27
6.1.6 Function code 05H: write single coil .......................................................................................................... 27
6.1.7 Function code 0FH: write multiple coils .....................................................................................................28
6.1.8 Function code 02H: read discrete input ...................................................................................................... 28
6.1.9 Function code 04H: read input register .......................................................................................................29
6.1.10 Function code 03H: read holding register .................................................................................................30
6.1.11 Function code 06H: write a single holding register .................................................................................. 30
6.1.12 Function code 10H: write to multiple holding registers ........................................................................... 31
6.1.13 Data area ....................................................................................................................................................31
6.1.14 Error feedback ........................................................................................................................................... 32
6.2 Modbus register table ......................................................................................................................................... 32
6.2.1 Device attribute related ............................................................................................................................... 32
6.2.2 Wireless properties related .......................................................................................................................... 34
6.2.3 Automatic polling related ............................................................................................................................ 35
6.2.4 Alarm function related .................................................................................................................................35
6.2.5 Low power consumption .............................................................................................................................36
Modification History .................................................................................................................................................... 38
About us ........................................................................................................................................................................38
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E90-DTU(400SL30L)_UserManual_EN
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