User Manual

User Guide
©2008-2020 Seeed Technology Co., Ltd. All rights reserved. solution.seeedstudio.com
2 / 23
Contents
1 Introduction ........................................................................................................................................... 3
2 Specifications ........................................................................................................................................ 4
3 Wiring .................................................................................................................................................... 5
4 Installation ............................................................................................................................................. 6
5 Modbus Communication Protocol ......................................................................................................... 7
5.1 Serial communication parameters ............................................................................................. 7
5.2 Modbus Register ........................................................................................................................ 8
5.3 Detail of Modbus Register ........................................................................................................ 10
5.4 Communication Sample ........................................................................................................... 15
5.4.1 Function number 3 communication sample .................................................................. 15
5.4.2 Function number 4 communication sample .................................................................. 16
5.4.3 Function number 6 communication sample .................................................................. 17
5.4.4 Function number 16 communication sample ................................................................ 18
5.5 CRC16 Check Algorithm .......................................................................................................... 21