Voltage and current values look ten times too high. Why?

The raw Modbus register values for voltage and current on all three phases use a scale factor of 10, meaning the raw integer must be divided by 10 to obtain the actual value in volts or amps. Confirm your portal or integration is applying this scaling correctly before displaying or alerting on these registers.

The gateway connects but all registers return zero or no data.

The most common cause is an incorrect Unit ID. Each PV inverter instance on the GX device is assigned a unique Unit ID. Navigate to Settings, Services, Modbus/TCP, Available services on the GX device to find the correct Unit ID for your PV inverter, then update the portal accordingly.

Energy counters on registers 1046, 1048, and 1050 show unexpected large values.

These uint32 cumulative energy registers use a scale factor of 100, so the raw value must be divided by 100 to get kWh. A raw value of 100000 equals 1000.00 kWh. Ensure your dashboard formula applies this divisor before comparing against billing or yield data.

Modbus TCP was working, then suddenly stopped returning data after a firmware update.

Victron GX firmware updates can reset the Modbus TCP service to disabled. After any firmware update, re-verify that Modbus TCP is still enabled under Settings, Services, and confirm the Unit ID assignments have not changed, as device instance numbers can shift if devices are reconnected.

Free Modbus template: Victron PV-Inverter

Name: Victron PV-Inverter
Brand: Victron
SKU: db7faff4-6403-4481-a688-6f1a625085aa

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Free Modbus template: Victron PV-Inverter | ModbusCloud

Registers (14)

14 read / 0 write

Name	Address	Function	Type	Unit	Access
position AC connection point: 0=AC input 1, 1=AC output, 2=AC input 2.	1026	FC03	uint16		R
voltage_l1 AC voltage on phase L1, scaled by 10 in raw register.	1027	FC03	uint16	V	R
current_l1 AC current on phase L1, signed, scaled by 10 in raw register.	1028	FC03	int16	A	R
active_power_l1 Instantaneous active power output on phase L1, watts.	1029	FC03	uint16	W	R
voltage_l2 AC voltage on phase L2, scaled by 10 in raw register.	1031	FC03	uint16	V	R
current_l2 AC current on phase L2, signed, scaled by 10 in raw register.	1032	FC03	int16	A	R
active_power_l2 Instantaneous active power output on phase L2, watts.	1033	FC03	uint16	W	R
voltage_l3 AC voltage on phase L3, scaled by 10 in raw register.	1035	FC03	uint16	V	R
current_l3 AC current on phase L3, signed, scaled by 10 in raw register.	1036	FC03	int16	A	R
active_power_l3 Instantaneous active power output on phase L3, watts.	1037	FC03	uint16	W	R
serial_number Device serial number as a 7-character ASCII string.	1039	FC03	string		R
active_production_energy_l1 Cumulative AC energy produced on phase L1, kWh, scaled by 100.	1046	FC03	uint32	kWh	R
active_production_energy_l2 Cumulative AC energy produced on phase L2, kWh, scaled by 100.	1048	FC03	uint32	kWh	R
active_production_energy_l3 Cumulative AC energy produced on phase L3, kWh, scaled by 100.	1050	FC03	uint32	kWh	R