Cerbo GX Max amount of AC Energy Meters via RS485. VRM Dashboard Display & Data

[PeakShaving (Ryan @ Peak Shaving)]

Hello Community,

I’m seeking clarity on how many RS485 meters can be connected to a Cerbo GX via a USB RS485 Modbus USB adapter, or multiple USBs if required.

I note in the Victron documentation it recommends to use separate USB adapters for each meter. Also mentions something about only meters configured as Modbus ID:1 or ID:2 will be detected?

I understand with Modbus RS485 is theoretically possible to have upto 32 meters each with own ID at full load? Easy to set individual IDs on models with displays.

I have only installed max of 2 meters on any system to date, single USB with ID 1 & 2, and a terminating 120ohm traitor at end with no problems.

Reason asking is have a project in which a Grid Parallel Victron based Storage system is to be considered, however there is already existing Grid-Tied Solar PV x 2 systems and a Wind Turbine Generator

Layout as below. Note no battery storage installed yet. All generation devices 3-phase.

I am wondering is it possible to install a Cerbo GX along with 4 X meters, e.g. Carlo Gavazzi EM530 as above, to get an understanding of site generation and usage with a view of installing a battery system at a later date. Would this work?

Meter 1 to monitor Grid Import & Export. Meter role set as Grid

Meter 2 to monitor PV system 1, role set as PV Inverter.

Meter 3 to monitor PV system 2, role set as PV Inverter as a above.

Meter 4 for wind turbine. Maybe set role as Generator?

Has anyone connected more than 2 x Energy Meters via RS485?

Alternatively to RS485 RTU has anyone use more than 2 X network connected Modbus TCP meters each with own IP address? Is that possible ot again does the 2 limitation become a factor?

Also has anyone implemented a Quattro setup with Grid and Generator and also a Grid-Tied / AC-Coupled PV Inverter. Keen to see how this is displayed visually on the new GUI. Can you see power of all 3 simultaneously?

Without having any Multiplus or quattro or battery storage installed, in curious to know if setup correctly would the Cerbo GX display and summarise import, export, PV generation, wind Generation (as Generator) and calculate load usage correctly?

Also wondering if 2 meters are connected as same role, does the Victron algorithms summate the data?

E.g. if 2 PV inverters and let’s say one is doing 10kW and one 20kW would 30kW be displayed?

Any advice welcome

[PeakShaving (Ryan @ Peak Shaving)]

I note In the documentation it states a GX device can be used with energy meters initially to collect data to enables system to be sized to requirements.

If anyone has done this with multiple meters would welcome feedback on how well it worked.

[PeakShaving (Ryan @ Peak Shaving)]

We have commenced a trial installing a Cerbo GX along with 2 Carlo Gavazzi Energy meters on a project site to asses power and energy usage from grid and performance of an existing Solar PV array.

Meter 1 EM530 with 100A CTs, set as Grid

Meter 2 EM540 65A direct connect, set as PV inverter

All works well, and dashboard is perfect on the connected Touch 70 display or via remote console, where measured Grid, measured PV and calculated load is correct.

However having a strange issue on VRM where the Grid meter seems to be duplicated and there is no power flow dashboard!

See images.

Now the VRM screenshot

Any ideas?

Thanks

[liamthomas]

It’s true that the Cerbo GX can technically support multiple RS485 energy meters, but in practice, stability often depends on how well the communication line is terminated and how the Modbus IDs are assigned. Most installers report smooth performance when using up to two or three meters per USB RS485 adapter, provided each device has a unique ID and proper termination at the end of the chain.

When planning a larger setup, it’s usually more reliable to dedicate a separate USB adapter to each group of meters to avoid data conflicts or lag in the VRM dashboard. In multi-source systems involving both solar PV and wind generation, isolating each energy stream with its own adapter tends to make data monitoring and fault tracing far simpler.

Proper shielding and grounding are also crucial, especially in installations where multiple meters are spread across longer distances. It’s the same principle used in precision control environments, consistent communication and clean data input are key to accurate monitoring. You can learn more about optimizing electrical setups and maintaining consistent system performance through regular inspection and service practices, which often help prevent Modbus errors and data duplication on complex energy systems.

In your case, using dedicated adapters for each meter or type of generation (Grid, PV, Wind) will likely give you the most stable dashboard performance and prevent issues such as meter duplication in VRM.