Victron Cerbo GX
Monitors grid, PV, battery, and consumption data from a Victron Cerbo GX energy system
Template for the Victron Cerbo GX via Modbus TCP. Reads grid power per phase, PV output, AC consumption, battery state of charge, battery voltage, charger power, and DC system power. Also provides control of two relay outputs.
- Protocol
- Modbus TCP
- Connection
- Ethernet, Modbus TCP
- Registers
- 20, read and write
- Brand
- VICTRON
- Key readings
- Grid L1 to L3 · PV AC-coupled output L1 to L3 · AC Consumption L1 to L3 · Battery State of Charge · Battery Voltage · Charger power
- Available commands
- Relay 1 status · Relay 2 status
- Compatible models
- Cerbo GX
- Last updated
Registers (20)
18 read, 2 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Grid L1 | Read | ||||
| Grid L2 | Read | ||||
| Grid L3 | Read | ||||
| PV - AC-coupled on output L1 | Read | ||||
| AC Consumption L1 | Read | ||||
| Battery State of Charge (System) | % | Read | |||
| PV - AC-coupled on output L2 | Read | ||||
| PV - AC-coupled on output L3 | Read | ||||
| AC Consumption L2 | Read | ||||
| AC Consumption L3 | Read | ||||
| Genset L1 | Read | ||||
| Battery Voltage (System) | V | Read | |||
| Charger power | W | Read | |||
| DC System Power | W | Read | |||
| Power between meter and inverter/charger, L1 | W | Read | |||
| Power between meter and inverter/charger, L2 | W | Read | |||
| Power between meter and inverter/charger, L3 | W | Read | |||
| L1 Power | W | Read | |||
| Relay 1 status | Write | ||||
| Relay 2 status | Write |
Loading registers…
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Monitor grid import and export per phase on a live dashboard for your customer.
- Track battery state of charge and voltage to detect abnormal discharge patterns over time.
- Create an alert when PV AC-coupled output drops to zero during daylight hours unexpectedly.
- Log AC consumption per phase to identify load imbalances in a three-phase installation.
- Control the Cerbo GX relay outputs remotely to switch external loads based on energy thresholds.
- Compare grid power and PV production in reports to evaluate self-consumption ratios.
Installation
Connect the ModbusCloud Gateway to the same local network as the Victron Cerbo GX.
Open the Cerbo GX remote console and navigate to Settings, then Services, and enable Modbus TCP.
Note the IP address of the Cerbo GX and configure it as the Modbus TCP target in the ModbusCloud gateway settings.
Set the Modbus TCP port to 502 (the default for the Cerbo GX) in the gateway configuration.
Import the Victron Cerbo GX template from the ModbusCloud library and assign it to the gateway connection.
Verify that readings for grid power, PV output, battery state of charge, and relay status appear correctly in the ModbusCloud dashboard.
Things to watch for
Modbus TCP connection fails. What should I check?
Ensure Modbus TCP is enabled in the Cerbo GX under Settings, Services. Verify that the gateway and the Cerbo GX are on the same network subnet and that port 502 is not blocked by a firewall.
Some power readings show incorrect or very large values. Why?
Registers at addresses 872, 874, and 876 are int32 and span two consecutive registers. If the byte or word order is set incorrectly, values will be misread. Confirm that the register data types match the CCGX Modbus TCP register list from Victron.
Battery state of charge reads zero even though the battery is charged. What is wrong?
The Cerbo GX only reports battery data if a compatible battery monitor or inverter/charger is connected and recognized. Check the device list on the Cerbo GX remote console to confirm the battery monitor is detected.
Can I use this template with a Venus GX or Color Control GX instead of a Cerbo GX?
The Modbus TCP register map is shared across Victron GX devices. The template should work with a Venus GX or Color Control GX, but you should verify register availability against the official CCGX Modbus TCP registry for your firmware version.
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