All grid registers return zero or an error. What is wrong?

Modbus TCP is disabled by default on GX devices. Navigate to Settings, Services, Modbus TCP on the GX device and enable the service. Also confirm that no firewall or VLAN is blocking TCP port 502 between the ModbusCloud Gateway and the GX device's IP address.

I get valid data but the Unit ID keeps timing out.

The Unit ID for the grid meter is not fixed. It depends on the device instance assigned by Venus OS and is shown under Settings, Services, Modbus TCP, Available services. Using Unit ID 0 is unreliable because many Modbus TCP clients do not accept it. Use the instance-specific ID listed there instead.

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

The voltage and current registers carry a scale factor of 10 in the official Victron Modbus TCP register list, meaning the raw int16 value must be divided by 10 to obtain the actual reading in volts or amperes. Verify that your portal scaling configuration matches this factor.

Energy counter registers 2622 to 2633 have no unit. What are they in?

The official Victron register documentation lists these cumulative energy counters in kWh with a scale factor applied. The unit field in this template is empty because the OpenEMS import did not carry it. Consult the Victron CCGX Modbus TCP register list spreadsheet to confirm the exact scale factor for your firmware version before building dashboards or billing reports.

Free Modbus template: Victron Meter Grid

Name: Victron Meter Grid
Brand: Victron
SKU: 474ab98f-0e4f-429a-ae16-268f7f32059d

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Free Modbus template: Victron Meter Grid | ModbusCloud

Registers (16)

16 read / 0 write

Name	Address	Function	Type	Unit	Access
active_power_l1 AC active power on phase L1, positive = import, negative = export.	2600	FC03	int16	W	R
active_power_l2 AC active power on phase L2, positive = import, negative = export.	2601	FC03	int16	W	R
active_power_l3 AC active power on phase L3, positive = import, negative = export.	2602	FC03	int16	W	R
serial_number Grid meter serial number as an ASCII string.	2609	FC03	string		R
voltage_l1 AC line-to-neutral voltage on phase L1, in volts.	2616	FC03	uint16	V	R
current_l1 AC current on phase L1, in amperes, signed.	2617	FC03	int16	A	R
voltage_l2 AC line-to-neutral voltage on phase L2, in volts.	2618	FC03	uint16	V	R
current_l2 AC current on phase L2, in amperes, signed.	2619	FC03	int16	A	R
voltage_l3 AC line-to-neutral voltage on phase L3, in volts.	2620	FC03	uint16	V	R
current_l3 AC current on phase L3, in amperes, signed.	2621	FC03	int16	A	R
active_consumption_energy_l1 Cumulative energy consumed from the grid on phase L1.	2622	FC03	uint32	Wh	R
active_consumption_energy_l2 Cumulative energy consumed from the grid on phase L2.	2624	FC03	uint32	Wh	R
active_consumption_energy_l3 Cumulative energy consumed from the grid on phase L3.	2626	FC03	uint32	Wh	R
active_production_energy_l1 Cumulative energy exported to the grid on phase L1.	2628	FC03	uint32	Wh	R
active_production_energy_l2 Cumulative energy exported to the grid on phase L2.	2630	FC03	uint32	Wh	R
active_production_energy_l3 Cumulative energy exported to the grid on phase L3.	2632	FC03	uint32	Wh	R