SI Gateway connects to your Sunsynk inverter over RS485 and turns raw data into a clean local dashboard — with remote access, Home Assistant integration, historical analytics and no cloud dependency for local control. It is the backbone of the SI ecosystem.
How it fits together
SI Gateway bridges your inverter to the rest of the SI ecosystem. It reads raw inverter data via RS485, calculates the ECM score, and exposes it via a local HTTP endpoint — which every connected SI device polls directly. Dashboard and Home Assistant telemetry flows over MQTT; SI devices use HTTP and don't depend on a broker at all.
Capabilities
Solar PV output, battery SOC, grid import/export and load — live on your dashboard. Every value that matters, always current.
Dashboard and device logic run on your local network. No cloud account required, no internet dependency for monitoring, control or automation.
View your system from anywhere via an encrypted managed tunnel. First 12 months included. No router configuration. No third-party tunnel service.
Every inverter entity exposed via MQTT. Solar, battery, grid and load available in HA the moment a broker is configured — no custom integration required.
Multiple SI Gateways per account — for larger sites, multi-phase systems or properties with more than one inverter. Each Gateway pairs independently.
Log inverter performance over time. Review daily solar yield, battery cycles, grid dependency and load patterns. Identify inefficiencies and anomalies across weeks and months.
Installers can access the system remotely for configuration, diagnostics and troubleshooting — with customer permission. Reduces callout costs for both parties.
SI Gateway is the coordination layer for the whole SI platform. It aggregates telemetry from SI Pool, SI Water and future products — enabling cross-domain automations like battery-aware heating and solar-surplus pool heating.
App Preview
Live solar production, ECM score, battery state and grid status — all updated in real time from anywhere.
App Store is a service mark of Apple Inc., registered in the U.S. and other countries.
Track the value
Set your electricity tariff once and SI Gateway tracks the numbers automatically — grid cost, solar savings, and net savings today, this month, and over the lifetime of the system.
Solar independence percentage gives you an instant read on how much of today's energy came from the sun vs the grid. No spreadsheets. No guesswork.
Real number from an active SI site — tariff R 3.10/kWh.
SI Gateway is not a data logger. It is the supervisory brain of a distributed residential utility intelligence system — aggregating telemetry, coordinating automations, and providing the operational visibility that lets the whole ecosystem think across energy, water and pool.
Technical Specifications
| Function | RS485 → Wi-Fi bridge (one per inverter) |
| Protocol | Modbus RTU over RS485 |
| Connectivity | Wi-Fi 2.4 GHz |
| Power | External power supply (included) |
| Cable | RS485 → RJ45 (included) |
| Inverter | Sunsynk (current); architecture inverter-agnostic |
| Dashboard | Web app — any browser, any device |
| Connection | MQTT over WSS — local or remote |
| Remote access | Encrypted tunnel — first 12 months |
| Multi-gateway | Yes — multiple gateways per account |
| Cloud required | No — local-first, cloud additive |
Compatible With
SI Gateway is installer-deployed. Talk to us and we'll connect you with an approved installer in your area.