SMA Solar
Sunny Tripower SunSpec Modbus for KNX PV yield monitoring and SG Ready control
SMA Solar Technology (Niestetal, Germany) is Germany's largest solar inverter manufacturer. Sunny Boy (residential) and Sunny Tripower (commercial, 15–33 kW) support SunSpec Modbus TCP — the industry-standard register map for solar inverters.
Role in our panels
How we use SMA Solar
The SunSpec Common Model defines a standard register map for solar inverters adopted by over 200 manufacturers including SMA, Fronius, ABB, and Huawei. On SMA Sunny Boy and Sunny Tripower inverters, Modbus TCP is enabled via the inverter webserver: Device > Settings > Modbus > TCP Enabled (toggle on), port 502 (fixed). The SunSpec Common Model block starts at register 40000: Register 40001 (SunSpec ID = 0x53756e53), Register 40002 (block ID), then Common Model Block at 40003–40020 (manufacturer, model, serial number, firmware version). The inverter model block follows at 40070 (block length depends on model). Key SunSpec registers for KNX integration on SMA Sunny Tripower: Reg 40083 = AC Power (W, int16, signed), Reg 40093 = AC Energy Lifetime (Wh, uint32, cumulative), Reg 40095 = DC Power (W, int16), Reg 40107 = Inverter Status (enum: 1=Off/2=Sleeping/3=Starting/4=MPPT/5=Throttled/6=Shutting Down/7=Fault/8=Standby). The SMA Energy Meter (separate DIN-rail device) adds grid import/export metering: Reg 0x0200 = Grid Active Power (W, uint32, signed 32-bit — positive=import, negative=export), Reg 0x0210 = Grid Energy Import Total (kWh × 0.001, uint32). Sunny Home Manager 2.0 (SMA-SHM2) extends the SMA ecosystem with direct SunSpec Modbus TCP plus the SMA proprietary energy manager protocol. The SHM2 also reads connected SMA Wallbox, SMA EV Charger, and Smart Home devices, providing a higher-level energy management register set. For KNX integration, the SHM2 Modbus TCP endpoint can replace direct inverter polling — SHM2 exposes net grid power (already calculated combining inverter output and household consumption) simplifying KNX logic design. Intesis IN701KNX gateway configuration for SMA SunSpec: add Modbus TCP device (SMA inverter IP, port 502), configure polling interval (5 seconds for real-time PV monitoring), map registers to KNX GAs: GA 9/0/0 (PV power DPT 13.010 W from Reg 40083), GA 9/0/1 (grid power signed DPT 13.010 from SMA Energy Meter Reg 0x0200), GA 9/0/2 (PV energy today DPT 13.013 — calculated from daily counter), GA 9/0/3 (inverter status DPT 5.001 from Reg 40107). KNX logic: IF GA 9/0/1 < -2000 (exporting 2 kW to grid) THEN write SG Ready State 3 to heat pump KNX relay GA — this activates DHW boost during solar surplus.
SMA Sunny Tripower/Boy: enable Modbus TCP in inverter webserver (Device > Settings > Modbus > TCP On, port 502). SunSpec Common Model: Reg 40083 = AC Power (W, int16), Reg 40093 = AC Energy total (Wh, uint32), Reg 40095 = DC Power (W, int16). SMA Energy Meter (separate DIN rail device): Reg 0x0200 = Grid Power (W, uint32, signed), Reg 0x0210 = Grid Energy Import (kWh × 0.001, uint32). Intesis IN701KNX: map registers to KNX GAs: GA 9/0/0 (PV power DPT 13.010), GA 9/0/1 (grid power signed DPT 13.010), GA 9/0/2 (PV today energy DPT 13.013). KNX logic: grid power < -2000W (exporting) → SG Ready State 3 on heat pump.
Used in these project types
SMA Solar products
Key components we install
Sunny Boy 5.0
5 kW single-phase string inverter with SunSpec Modbus TCP. Up to 2 DC string inputs (750V max). SMA OptiTrac Global Peak shade optimisation. Webserver access on port 80 (username/password required). Modbus TCP enable in webserver settings. SunSpec Common Model registers identical to Sunny Tripower — same Intesis IN701KNX gateway configuration. Used for residential PV 3–6 kWp with standard string configuration. For single-phase installation with SMA Energy Meter: combined grid power reading provides KNX self-consumption optimisation data.
Sunny Tripower 25000TL
25 kW 3-phase commercial string inverter with SunSpec Modbus TCP. Three MPPT inputs for multi-string commercial rooftops. SMA Speed Wire (Ethernet + RS-485) for SMA cluster communication. Modbus TCP on port 502. Registers: AC Power total 3-phase (Reg 40083), AC Energy (Reg 40093), DC Power each MPPT. Used in commercial rooftop PV 20–100 kW with multiple Sunny Tripower in parallel. For KNX integration: multiple inverters can be polled from single Intesis IN701KNX — each inverter has unique Modbus unit ID (configurable in webserver).
Sunny Home Manager 2.0
SMA energy manager combining SunSpec Modbus TCP with SMA proprietary load management. Reads SMA inverters, SMA EV Charger, and smart home plugs. Exposes household consumption, PV generation, grid import/export, and self-consumption ratio via Modbus TCP (same port 502). For KNX integration, SHM2 provides pre-calculated net grid power reducing KNX logic complexity — single Modbus register for grid balance rather than separate inverter + meter polling. Compatible with Intesis IN701KNX.
SMA Energy Meter
DIN-rail 3-phase bidirectional energy meter with Modbus TCP server (port 9522 — note different port from inverter port 502). Measures grid import, export, reactive power, and phase voltages. Required for self-consumption optimisation when PV inverter AC output and household loads are on different circuits (typical residential installation: inverter measured separately from grid connection). Register 0x0200 = Grid Active Power (signed). PanelCraft includes SMA Energy Meter in the panel specification for all SMA solar KNX projects.
Sunny Boy Storage
3.7–6 kW hybrid battery inverter for AC-coupled battery storage. Compatible with BYD Battery-Box Premium HV. SunSpec Modbus TCP registers include battery SOC, battery power (charge/discharge), and inverter state. DC-coupled version (SMA Sunny Tripower Storage) for new-build. Battery SOC register readable by Intesis IN701KNX → KNX GA for self-consumption optimisation logic. Note: write mode for SMA battery charging is not supported via Modbus — SG Ready relay on connected heat pump remains the primary KNX control mechanism for surplus PV management.
SMA Solar FAQ
What SunSpec Modbus TCP registers does SMA Sunny Tripower expose?
SMA Sunny Tripower SunSpec Common Model registers (read-only): Reg 40083 = AC Power total (W, int16, signed), Reg 40093 = AC Energy Lifetime (Wh, uint32 — requires 32-bit read), Reg 40095 = DC Power (W, int16), Reg 40107 = Inverter Operating State (enum: 4=MPPT normal operation, 7=Fault). For 3-phase models: per-phase AC power registers at 40072–40080. The SMA Energy Meter (separate device, port 9522) provides Reg 0x0200 = Grid Active Power signed (W) and Reg 0x0210 = Grid Import Energy (kWh × 0.001). Enable Modbus TCP in the inverter webserver under Device > Settings > Modbus — toggle on, port 502 fixed.
Does SMA require an additional Modbus gateway?
No — SMA Sunny Boy and Sunny Tripower have native SunSpec Modbus TCP built-in (enable in webserver settings). The only additional hardware needed is a KNX/Modbus TCP bridge: Intesis IN701KNX or Weinzierl KNX IP Interface 731 with Modbus capability. PanelCraft mounts the Intesis IN701KNX in the same DIN-rail panel as the Cerbo GX (if Victron is also present) or as a standalone gateway. Note: SMA Energy Meter uses a different port (9522) from the inverter (502) — configure two separate Modbus TCP connections in the Intesis gateway.
Can KNX control SMA battery storage charging?
SMA Sunny Boy Storage Modbus TCP registers are read-only for battery state — direct write control of charging mode is not supported via Modbus TCP (SMA does not expose battery mode write registers in the SunSpec standard). The recommended approach for KNX PV surplus management with SMA storage is: (1) read battery SOC from Modbus via KNX for monitoring and display; (2) control heat pump SG Ready relay from KNX PV surplus logic for load management; (3) use SMA Sunny Home Manager 2.0 charge management for battery charge/discharge scheduling — SHM2 handles storage optimisation internally while KNX handles external load management.
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