node-red-contrib-sma-sunspec 1.1.0
Node-RED nodes for reading and writing SMA inverters and smart meters via SunSpec Modbus TCP
node-red-contrib-sma-sunspec
Node-RED nodes for reading and writing SMA solar inverters and smart meters via SunSpec Modbus TCP.
No license keys, no cloud dependencies — just direct Modbus TCP to your SMA hardware.
Nodes
sma-inverter-read
Polls an SMA inverter or smart meter on a configurable interval and outputs structured data.
- Auto-discovery — finds the SunSpec base register and scans the model table automatically
- Device detection — editor probe button identifies the device type, unit ID, and available models
- Flexible output — full SunSpec envelope or selected individual fields
- Exponential backoff — retries with increasing delay on communication errors
Supported SunSpec models:
| Model | Type |
|---|---|
| 1 | Common (manufacturer, model, serial) |
| 101, 102, 103 | Inverter (integer scaled) — single/split/three-phase |
| 111, 112, 113 | Inverter (float) — single/split/three-phase |
| 160 | MPPT (DC string data) |
| 201–204 | Meter (integer scaled) — single/split/wye/delta |
| 211–214 | Meter (float) — single/split/wye/delta |
sma-inverter-write
Writes active power curtailment to an SMA inverter via SunSpec Model 123 (Immediate Controls).
- Readback verification — writes the setpoint, then reads back to confirm
- Heartbeat — re-writes periodically to keep the curtailment alive
- Deduplication — skips writes when the same setpoint is already confirmed
- Flexible input — accepts watts, percent, or structured objects
- 3-attempt retry with connection reset between attempts
Install
cd ~/.node-red
npm install node-red-contrib-sma-sunspec
Or search for node-red-contrib-sma-sunspec in the Node-RED palette manager.
Configuration
Both nodes need:
- Host — IP address of the SMA device
- Port — Modbus TCP port (default 502)
- Unit ID — Modbus slave ID (SMA inverters typically use 126, meters use 3)
Use the Detect Device / Detect Model 123 button in the editor to auto-discover.
sma-inverter-write input format
// Watts (number)
msg.payload = 5000;
// Watts (object)
msg.payload = { watts: 5000 };
// Percent of nominal power
msg.payload = { percent: 50 };
// Explicit mode
msg.payload = { value: 50, mode: "percent" };
Dependencies
- modbus-serial — Modbus TCP transport
License
MIT
