Read data from Hoymiles HMS microinverter using Hoymiles Modbus protocol.
Description
Hoymiles HMS-1000-2T microinverter data is read directly from DTU-PRO-S RS485 port. You need to setup Hoymiles DTU unit to "Remote Control/Modbus Protocol"-mode and set known Modbus address to DTU with Hoymiles installer application. RS485 adapter used is EasySync ES-U-3001-M and flow is developed and tested with Windows 10 machine and Raspberry PI 3 B+.
Default baudrate is 9600 bps. In this example Modbus address 254 is used.
Starting register for microinverter Modbus data is 0x1000 = 4096. Each inverter PV port data is 40 registers long. HMS-1000-T has two ports. Port 1 data can be read starting from register 4096 and port 2 data can be read starting from register 4096 + 40 = 4136. If there there more microinverters their data will be starting 4096 + (40 * n) register.
Install required nodes
Modbus communication is implemented using
https://flows.nodered.org/node/node-red-contrib-modbus
Data is parsed using:
https://flows.nodered.org/node/node-red-contrib-buffer-parser
npm install node-red-contrib-modbus
npm install node-red-contrib-buffer-parser
Sources
Hoymiles - Technical note - Modbus implementation using 3Gen DTU-Pro
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