solis-ha-modbus-cloud

Purpose

A combination of Solis Cloud, Home Assistant via RS485 (Modbus) communication. This repo is a documented workaround for Solis inverters to connect Solis Cloud and the local Home Assistant based on my own experience. It includes references, examples of the code in Home Assistant, more about configuration, as well as wiring and all required components.

Limitations and some history

My PV installation commenced back in August 2022. Since then, I started my journey with Home Assistant, and several Solis integrations made by some clever folks out there. My main goal was to keep Solis Cloud functionality and allow for advanced monitoring, remote control, and general automation of my home equipment. As I was going through my journey, I found many obstacles and limitations with Solis Cloud, dataloggers, and its design. Therefore, to get over those obstacles, I have designed the below, which meets my requirements and it works quite well.

Most importantly, my design doesn’t disconnect the Solis cloud, and works (coexists) with your local Home Assistant integration in combination with any Solis datalogger.

You can watch a great video from Gordon Markus summarising his 12-months experience and Solis inverters limitations - https://youtu.be/F7r12UjzZyU

Diagram

Diagram

Description

The main goal is to ensure that a datalogger can work as normal and without any distruption. The datalogger acts as the Master device, and it talks directly to the inverter (Slave). Having an additional Master (e.g., Waveshare Gateway) on the same RS485 network is to create collisions, which could affect all RS485 devices. Some dataloggers don’t accept multiple TCP connections (e.g., S2-WL-ST), and those will disconnect the Solis Cloud whenever used with an integration; others don’t support Modbus TCP (e.g., DLS-W, S3-WIFI-ST), and some will fully rely on the cloud (S3-WIFI-ST). Some obsolete dataloggers couldn’t provide remote functionality via Solis Cloud (e.g., DLS-W, DLS-L).

However, there are reports that remote functionality started working with obsolete dataloggers after Solis’ maintenance on 13 April 2023.

Here it comes the Waveshare gateway to query the inverter. It can serve multiple clients, keep the inverter’s cloud reporting functionality, and is not limited by any supported datalogger. The below is my configuration, but the use case could differ per datalogger.

The main device is the Waveshare RS485 to PoE ETH (B) - the non-PoE version is described as per this guideline. There are no major differences between PoE and non-PoE devices, except for the convenience of powering those when you have multiple next in line.

I was trying different settings as I had some teething issues, and I noticed that it works better when the integration (I am using Home Assistant SolaX Modbus integration for my Solis inverter) is polling data more often (e.g., every 5 seconds). As much as no longer relevant, you can find more about those issues at the following address.

Solution Concepts

DLS-W - Solis Sensor, Home Assistant Solax Modbus, SolisMon3, Grafana

Diagram

S2-WL-ST - Solis Sensor, Home Assistant Solax Modbus

Diagram

Wiring

I recommend using one of the pairs from the Ethernet cable for RS485 wiring. e.g., A twisted pair of blue for RS485(A) and white-blue for RS485(B). There is no need for 120 Ohms resistors at each end of the RS485. Both, Waveshare and the Inverter have resistors built-in.

Wiring

Configuration

Please use VirCom (not the Web Interface) to configure your Waveshare devices

TCP Server Config

server

More Advanced Settings for TCP Server

server-advanced

TCP Client Config

client

More Advanced Settings for TCP Client

client-advanced

HA Integrations

Datalogger/Waveshare - Modbus TCP - direct connection - e.g., DLS-L, S2-WL-ST, Waveshare RS485 to PoE ETH (B)

Datalogger - Solarman based - direct connection - e.g., DLS-W

Cloud connection - any Solis datalogger

MQTT

Supported Solis Dataloggers

Table

Untested Solis Dataloggers

Incompatible and untested Solis Dataloggers

The below will be incompatible with the 4-pin Exceedconn EC04681-2023-BF Male/Female connector, but could still work with the above HA Integrations

Devices and cost

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Total Cost

£148.50 (pricing out of date) or £93.00 if you follow this discussion #24

Optional to connect batteries:

Final Result

Final

Future work

DISCLAIMER

I AM NOT RESPONSIBLE FOR ANY USE OR DAMAGE THIS DESIGN MAY CAUSE. THIS IS INTENDED FOR EDUCATIONAL PURPOSES ONLY. USE AT YOUR OWN RISK.

DONATIONS

IF YOU FOUND THIS USEFUL, YOU CAN BUY ME A BEER

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