Why do some energy totals like PV Generation Year or Grid Import Total show incorrect values?

These registers use low-byte and high-byte pairs that must be combined to form the correct value. Check that your template is configured to merge both registers. The register mapping notes in the template indicate which pairs need combining.

Can I safely write to all 37 writable registers?

Writing to registers has been tested but may not always produce the expected result. Exercise caution with registers that control critical functions such as battery shutdown percentages or work mode. Test each write command individually before automating.

Which subset template should I use?

Use Subset A if you only need basic energy flow data. Use Subset B for detailed read-only monitoring. Use Subset C for full read and write control. Use Subset D if you need a broader set of read/write registers in sensor-only format. Most installations only require one or two subsets.

What baud rate or TCP port does the Sunsynk 8kW ECCO use for Modbus?

The inverter communicates over Modbus TCP, typically on port 502. Confirm the port and slave ID in the inverter settings before configuring the gateway connection.

Free Modbus template: Sunsynk 8kW ECCO Hybrid Inverter

Name: Sunsynk 8kW ECCO Hybrid Inverter
Brand: Sunsynk
SKU: da8355bc-1da3-46a6-9eb2-a8ed3c23be43

Modbus TCP template for the Sunsynk 8kW ECCO single-phase hybrid inverter. Reads 135 registers covering PV generation, battery status, grid import/export, load data, and inverter temperatures. Writes 37 registers for work mode, charge limits, timer schedules, and grid charge settings.

Registers (135)

135 read / 37 write

Name	Address	Function	Type	Unit	Access
001-Modbus_Address Inverter Modbus Address	1	FC03	int16		R
011-System_Firmware_Version System Firmware Version	11	FC03	int16		R
013-Main_Firmware_Version Main Firmware Version	13	FC03	int16		R
014-Comms_Firmware_Version Comms Firmware Version	14	FC03	int16		R
020-Remote_Control Allow Remote Control	20	FC03	int16		R
022-System_Time_Year/Month System Time - Year/Month	22	FC03	int16		R
023-System_Time_Day/Hour System Time - Day/Hour	23	FC03	int16		R
024-System_Time_Minute/Second System Time - Minute/Second	24	FC03	int16		R
036-Grid_Import_Power_Limit Grid Import Power Limit	36	FC03	int16	W	R
053-Max_Solar_Power Max Solar Power	53	FC03	int16	W	R
059-Inverter_Status Current inverter status	59	FC03	int16		R
065-PV_Generation_Month PV generation this month	65	FC03	int16	kWh	R
066-Load_Month Load this month	66	FC03	int16	kWh	R
067-Grid_Month Grid this month	67	FC03	int16	kWh	R
068-PV_Generation_Year_LowByte PV generation this year (low byte)	68	FC03	int16	kWh	R
069-PV_Generation_Year_HighByte PV generation this year (high byte)	69	FC03	int16	kWh	R
070-Battery_Charge_Today Battery charging today	70	FC03	int16	kWh	R
071-Battery_Discharge_Today Battery discharging today	71	FC03	int16	kWh	R
072-Battery_Charge_Total_LowByte Battery charge total (low byte)	72	FC03	int16	kWh	R
073-Battery_Charge_Total_HighByte Battery charge total (high byte)	73	FC03	int16	kWh	R
074-Battery_Discharge_Total_LowByte Battery discharge total (low byte)	74	FC03	int16	kWh	R
075-Battery_Discharge_Total_HighByte Battery discharge total (high byte)	75	FC03	int16	kWh	R
076-Grid_Import_Today Grid imported today	76	FC03	int16	kWh	R
077-Grid_Export_Today Grid exported today	77	FC03	int16	kWh	R
078-Grid_Import_Total_LowByte Grid import total (low byte)	78	FC03	int16	kWh	R
080-Grid_Import_Total_HighByte Grid import total (high byte)	80	FC03	int16	kWh	R
081-Grid_Export_Total_LowByte Grid export total (low byte)	81	FC03	int16	kWh	R
082-Grid_Export_Total_HighByte Grid export total (high byte)	82	FC03	int16	kWh	R
084-Load_Today Load today	84	FC03	int16	kWh	R
085-Load_Total_LowByte Load total (low byte)	85	FC03	int16	kWh	R
086-Load_Total_HighByte Load total (high byte)	86	FC03	int16	kWh	R
087-Load_Year_LowByte Load this year (low byte)	87	FC03	int16	kWh	R
088-Load_Year_HighByte Load this year (high byte)	88	FC03	int16	kWh	R
090-DC_Temp Temperature of the DC transformer	90	FC03	int16	°C	R
091-IGBT_Temp Temperature of the IGBT device	91	FC03	int16	°C	R
096-PV_Generation_Total_LowByte PV generation total (low byte)	96	FC03	int16	kWh	R
097-PV_Generation_Total_HighByte PV generation total (high byte)	97	FC03	int16	kWh	R
098-Grid_Export_Year_LowByte Grid export this year (low byte)	98	FC03	int16	kWh	R
099-Grid_Export_Year_HighByte Grid export this year (high byte)	99	FC03	int16	kWh	R
107-Battery_Capacity_(see204) Corrected Battery Capacity	107	FC03	int16	Ah	R
108-PV_Generation_Today PV generation today	108	FC03	int16	kWh	R
109-MPPT1_Voltage MPPT1 Voltage	109	FC03	int16	V	R
110-MPPT1_Current MPPT1 Current	110	FC03	int16	A	R
111-MPPT2_Voltage MPPT2 Voltage	111	FC03	int16	V	R
112-MPPT2_Current MPPT2 Current	112	FC03	int16	A	R
150-Grid_Voltage Grid side voltage L1-N	150	FC03	int16	V	R
154-Inverter_Output_Voltage Inverter output voltage L1-N	154	FC03	int16	V	R
157-Inverter_Load_Voltage Inverter load voltage L1	157	FC03	int16	V	R
160-Grid_Current Grid side current L1	160	FC03	int16	A	R
162-Grid_External_Limiter_Current Grid external limiter current L1	162	FC03	int16	A	R
164-Inverter_Output_Current Inverter output current L1	164	FC03	int16	A	R
167-Grid_Load_Power Grid load power L1	167	FC03	int16	kW	R
169-Grid_Import/Export Grid power	169	FC03	int16	kW	R
170-Grid_External_CT_Power Grid external CT power L1	170	FC03	int16	W	R
173-Inverter_Output_Power Inverter output power L1	173	FC03	int16	W	R
176-Inverter_Load_Output Inverter load output power L1	176	FC03	int16	W	R
179-Inverter_Load_Current Inverter load current L1	179	FC03	int16	A	R
182-Battery_Temp Battery temperature	182	FC03	int16	°C	R
183-Battery_Voltage Battery Voltage	183	FC03	int16	V	R
184-Battery_SOC% Battery state of charge (SOC)	184	FC03	int16	%	R
186-MPPT1_Power MPPT1 Power	186	FC03	int16	kW	R
187-MPPT2_Power MPPT2 Power	187	FC03	int16	kW	R
190-Battery_Power Battery circuit power	190	FC03	int16	kW	R
191-Battery_Current Battery circuit current	191	FC03	int16	A	R
194-Grid_Connection Grid connection status	194	FC03	int16		R
200-Battery_Type Battery type	200	FC03	int16		R
201-Equalisation_Voltage Battery equalisation voltage	201	FC03	int16	V	R
202-Absorbtion_Voltage Battery absorbtion voltage	202	FC03	int16	V	R
203-Float_Voltage Battery float voltage	203	FC03	int16	V	R
204-Battery_Capacity_(see107) Battery capacity	204	FC03	int16	Ah	R
205-Battery_Empty_Voltage Battery empty voltage	205	FC03	int16	V	R
206-Grid_Trickle_Feed Grid trickle feed	206	FC03	int16	W	R/W
207-Equalisation_Day_Cycle Battery equalisation day cycle	207	FC03	int16	d	R
208-Equalisation_Time Battery equalisation time	208	FC03	int16	h	R
210-Max_Charge_Amps Battery max charging rate	210	FC03	int16	A	R/W
211-Max_Discharge_Amps Battery max discharging rate	211	FC03	int16	A	R/W
213-Battery_Settings_(use SOC or V?) Use SOC or Voltage for battery settings	213	FC03	int16		R
214-Battery_Activation_Flag Battery activation	214	FC03	int16		R
216-Battery_Charging_Efficiency Battery charging efficiency	216	FC03	int16	%	R
217-Battery_Shutdown_Percent Battery shutdown %	217	FC03	int16	%	R/W
218-Battery_Restart_Percent Battery restart %	218	FC03	int16	%	R/W
219-Battery_Low_Percent Battery low %	219	FC03	int16	%	R/W
220-Battery_Shutdown_Voltage Battery shutdown voltage	220	FC03	int16	V	R
221-Battery_Restart_Voltage Battery restart voltage	221	FC03	int16	V	R
222-Battery_Low_Voltage Battery low voltage	222	FC03	int16	V	R
230-Grid_Charge_Amps Grid charging current	230	FC03	int16	A	R/W
232-Grid_Charge Grid charging enabled	232	FC03	int16		R/W
243-Energy_Management Energy management	243	FC03	int16		R/W
244-Work_Mode Work mode	244	FC03	int16		R/W
245-Inverter_Max_Sell_Power Inverter max export power	245	FC03	int16	W	R/W
247-Solar_Export Allow solar export	247	FC03	int16		R/W
248-Use_Timer Use timer settings	248	FC03	int16		R/W
250-Timer_1_Start Timer 1 Start	250	FC03	int16	<3v>	R/W
251-Timer_2_Start Timer 2 Start	251	FC03	int16		R/W
252-Timer_3_Start Timer 3 Start	252	FC03	int16		R/W
253-Timer_4_Start Timer 4 Start	253	FC03	int16		R/W
254-Timer_5_Start Timer 5 Start	254	FC03	int16		R/W
255-Timer_6_Start Timer 6 Start	255	FC03	int16		R/W
256-Timer_1_Power Timer 1 Power	256	FC03	int16	W	R/W
257-Timer_2_Power Timer 2 Power	257	FC03	int16	W	R/W
258-Timer_3_Power Timer 3 Power	258	FC03	int16	W	R/W
259-Timer_4_Power Timer 4 Power	259	FC03	int16	W	R/W
260-Timer_5_Power Timer 5 Power	260	FC03	int16	W	R/W
261-Timer_6_Power Timer 6 Power	261	FC03	int16	W	R/W
262-Timer_1_Battery_Voltage Timer 1 Battery Voltage	262	FC03	int16	V	R
263-Timer_2_Battery_Voltage Timer 2 Battery Voltage	263	FC03	int16	V	R
264-Timer_3_Battery_Voltage Timer 3 Battery Voltage	264	FC03	int16	V	R
265-Timer_4_Battery_Voltage Timer 4 Battery Voltage	265	FC03	int16	V	R
266-Timer_5_Battery_Voltage Timer 5 Battery Voltage	266	FC03	int16	V	R
267-Timer_6_Battery_Voltage Timer 6 Battery Voltage	267	FC03	int16	V	R
268-Timer_1_SOC Timer 1 SOC	268	FC03	int16	%	R/W
269-Timer_2_SOC Timer 2 SOC	269	FC03	int16	%	R/W
270-Timer_3_SOC Timer 3 SOC	270	FC03	int16	%	R/W
271-Timer_4_SOC Timer 4 SOC	271	FC03	int16	%	R/W
272-Timer_5_SOC Timer 5 SOC	272	FC03	int16	%	R/W
273-Timer_6_SOC Timer 6 SOC	273	FC03	int16	%	R/W
274-Timer_1_Grid_Charge Timer 1 Grid/Generator Charge	274	FC03	int16		R/W
275-Timer_2_Grid_Charge Timer 2 Grid/Generator Charge	275	FC03	int16		R/W
276-Timer_3_Grid_Charge Timer 3 Grid/Generator Charge	276	FC03	int16		R/W
277-Timer_4_Grid_Charge Timer 4 Grid/Generator Charge	277	FC03	int16		R/W
278-Timer_5_Grid_Charge Timer 5 Grid/Generator Charge	278	FC03	int16		R/W
279-Timer_6_Grid_Charge Timer 6 Grid/Generator Charge	279	FC03	int16		R/W
280-Advance_Aux_Settings Advance/Aux Settings	280	FC03	int16		R
293-Grid_Peak_Shaving_Power Grid peak shaving power	293	FC03	int16	W	R
312-BMS_Charge_Voltage BMS Battery Charging Voltage	312	FC03	int16	V	R
314-BMS_Charge_Current_Limit BMS Battery Charging Current Limit	314	FC03	int16	A	R
315-BMS_Discharge_Current_Limit BMS Battery Discharging Current Limit	315	FC03	int16	A	R
316-BMS_SOC BMS Battery SOC%	316	FC03	int16	%	R
317-BMS_Battery_Voltage BMS Battery Voltage	317	FC03	int16	V	R
318-BMS_Battery_Current BMS Battery Current	318	FC03	int16	A	R
319-BMS_Battery_Temp BMS Battery Temperature	319	FC03	int16	°C	R
325-BMS_Protocol Battery BMS communication protocol	325	FC03	int16		R
326-External_Meter_CT External Meter CT Settings	326	FC03	int16		R
327-CT_Ratio CT clamp ratio	327	FC03	int16		R
330-Basic_Settings Basic Settings	330	FC03	int16		R

Sunsynk 8kW ECCO Hybrid Inverter

Overview

Key readings

Available commands

Use cases

Installation

Things to watch for

Registers (135)

Working with Modbus in your projects?

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