question

aribes avatar image
aribes asked

Cerbo GX exchange table

Hello,

We are working on a micro-grid project in which the Cerbo GX acts as the central controller. It will be connected to multiple pylontech US5000 batteries (via BMS-CAN) and PV solar panels (along with several Victron RS450/200 via VE.can and several Quattro 48/10000 inverters via VE Bus RJ45), forming a system capable of grid-forming. Another PV field is part of the power plant and will directly inject power into the grid (Fronius inverter via Modbus TCP). Our client is adding their own daily storage system that we need to control, and for that, we need to have a perfect understanding of the system's state.

The question concerns the Modbus TCP exchange table and the variables to query on the Cerbo GX to obtain the data we're interested in (https://www.victronenergy.fr/panel-systems-remote-monitoring/cerbo-gx#technical-information - CCGX-Modbus-TCP-register-list-3.00.xlsx). We would like to validate our understanding of it:

  • com.victronenergy.system: global data (sums of inverters, batteries, grid frequency, etc.)?
  • com.victronenergy.VEbus: Quattro inverters? Should we repeat the registers for each inverter using unit IDs from 20 to 29?
  • com.victronenergy.battery: pylontech batteries? Addresses 259 to 326 for alarms and measurements, and addresses 1282 to 1318 for statuses? Should we repeat the registers for each battery using unit IDs from XX to XX? Or is only 225 available?
  • com.victronenergy.solarcharger: smart solar RS? Should we repeat the registers for each device using unit IDs from 1 to 9 (and 100)?
  • On which register are the addresses located? Holding register? Input register?
  • Does the provided scale directly indicate the unit (dbus-unit), or should we multiply it by the scale to obtain the unit?

Thank you for your help,

Antoine

cerbo gxMPPT SmartSolarPylontechquattro 10kvamicrogrid
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

3 Answers
wkirby avatar image
wkirby answered ·

com.victronenergy.system value are like system global values. Use unit ID 100 to read these holding registers.
Here I read system battery Voltage. Scale factor is 10, so divide the value by 10 to get 49.8V.
1687980123371.png

Those values could be available elsewhere too.
Here I read the battery Voltage direct from the Pylontech battery, it has an additional decimal place in this case, Scale factor 100, so divide by 100 to get 49.80V.
1687980426300.png


com.victronenergy.vebus
Use the unit ID of the VE.Bus system. For a CerboGX this should be 227.
All three Quatros configured as a three phase system present as a single VE.Bus system with one unit ID for all. Then use the address for the value you want, 15 for L1 output Voltage, 16 for L2 output Voltage etc.

com.victronenergy.battery
All Pylontech battery modules present as one on 225.
Use registers 258 - 327 and 1282 - 1318. However, not all parameters will return values for Pylontech batteries, only some of them depending upon if Pylontech transmit that value or not.
The registers support a variety of different battery manufacturers, so values present for one manufacturer may not be present for another.

com.victronenergy.solarcharger
For VE.Can RS Solar devices use a different unit ID for each one 1 - 9 or 100 depending upon how your system enumerates the slaves.

As you can see above images, read holding registers, function code 3.

Also in the examples above, divide the returned value by the scale factor to get the actual value.


1687980123371.png (47.2 KiB)
1687980426300.png (46.9 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

aribes avatar image
aribes answered ·

We will try that and keep you posted, thank you very much !

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

aribes avatar image
aribes answered ·

Hello again,
If we would want to connect the FRONIUS inverters to the cerbo GX so that we can read everything at the same place, would it work and how would you do that ?
Thank you,

Have a nice weekend

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.