Modbus Reference · SunSpec

SolarEdge & SunSpec Modbus TCP registers

Register reference for reading SolarEdge inverters and other SunSpec-compliant devices (SMA, Fronius, Fimer) over local Modbus TCP: production, identification, status, battery, and meter.

Connection parameters: Modbus TCP on port 1502 (SolarEdge default; many other SunSpec brands use 502), function code FC03 (Read Holding Registers). The default unit ID is 1. Note: SMA devices commonly expose their SunSpec map at unit ID 126. SolarEdge inverters accept one Modbus TCP connection at a time.

Production registers (SunSpec inverter model)

Function	Register(s)	Raw format	Scaling	Metric	App output
FC03	40083	S16	× 10^40084	Instantaneous AC power, W	Watts
FC03	40084	S16	Scale factor	Power scale factor (W_SF)	Scales 40083
FC03	40093–40094	U32	× 10^40095	Lifetime energy production	Wh
FC03	40095	S16	Scale factor	Lifetime-energy scale factor (WH_SF)	Scales 40093–40094
FC03	40079	U16	× 10^40082	AC voltage, phase A / line-to-neutral	Volts
FC03	40080–40081	U16	Not used	Additional AC voltage phases	Read in block, ignored
FC03	40082	S16	Scale factor	Voltage scale factor (Voltage_SF)	Scales 40079

Efficient block read: 40083–40095 in one request, plus the voltage block 40079–40082.

Device identification (SunSpec common model)

Register(s)	Function	Data	Meaning
40005–40012	FC03	8 registers, text	Manufacturer name
40013–40020	FC03	8 registers, text	Model name
40021–40024	FC03	4 registers	Options
40025–40028	FC03	4 registers, text	Firmware / version information
40029–40036	FC03	8 registers, text	Serial number

Device discovery reads 40005–40036 as one block.

Inverter operating status

Register	Function	Raw type	Meaning
40107	FC03	U16	SunSpec inverter operating status

Code	Status	Healthy?
1	Off	No
2	Sleeping	Yes
3	Starting	Yes
4	Producing	Yes
5	Throttled	Yes
6	Shutting down	No
7	Fault	No
8	Standby	Yes

Battery registers (SolarEdge and StorEdge)

Battery type	Function	Register(s)	Raw format	Scaling	Metric
SolarEdge default	FC03	17707–17708	Float32	Direct	Battery state of charge, %
SolarEdge default	FC03	17709–17710	Float32	Direct	Battery power, W
SolarEdge StorEdge	FC03	57708–57709	Float32	Direct	Battery temperature, °C
SolarEdge StorEdge	FC03	57712–57713	Float32	Direct	Battery voltage, V
SolarEdge StorEdge	FC03	57716–57717	Float32	Direct	Battery power, W
SolarEdge StorEdge	FC03	57732–57733	Float32	Direct	Battery state of charge, %

Grid meter registers (SunSpec meter, Model 201)

The default SunSpec meter base address is 40121. Readings start at base + 10, so the default read range is 40131–40143. The base address can be changed for a different SunSpec meter location.

Default register(s)	Relative position	Raw format	Scaling	Metric
40131	Base + 10	S16	× 10^40132	Instantaneous grid power
40132	Base + 11	S16	Scale factor	Power scale factor
40133–40138	Base + 12 to +17	Various	–	VA, VAR, power factor (read, ignored)
40139–40140	Base + 18 to +19	U32	× 10^40141	Cumulative exported energy
40141	Base + 20	S16	Scale factor	Energy scale factor
40142–40143	Base + 21 to +22	U32	Uses 40141	Cumulative imported energy

Sign conventions used throughout: grid power is normalized so positive = exporting and negative = importing. Battery power is normalized so charging and discharging follow the app's convention noted per table.

Which devices use this map?

SolarEdge inverters (SetApp-era and LCD models), SMA Sunny Boy and Sunny Tripower, Fronius GEN24 and SnapINverter (via Datamanager 2.0), Fimer UNO-DM and REACT2, and other inverters implementing SunSpec models 101/103. In SolarMark, select "SunSpec Standard" when adding these devices. Setup guides: SolarEdge, SMA, Fronius.

Want this data on your phone, without a server?

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