Fronius Primo not showing in VRM device list after converting system to off-grid / microgrid setup

DIY
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1

Hello Victron Community,

I have converted my system to an off-grid setup. The following equipment is already installed and running:

  • Manual transfer switch

  • Victron MultiPlus-II 48/5000/70-80

  • MPPT 450/100

  • MPPT 150/35

  • Pylontech battery system with 8 modules, 400 Ah total

  • Cerbo GX with VRM connection

In VEConfigure for the MultiPlus, I added the PV Inverter Support Assistant and configured the following values:

  • PV restart when battery voltage level is lower than 50.20 V

  • Frequency settings: 50.20 Hz start / 52.70 Hz minimum / 53.00 Hz off

  • Installed PV inverter power: 3600 W

  • Installed PV panel power: 2400 W

The Fronius Primo 3.6 kW has the static IP address 192.168.178.160 and is reachable via its web interface over WiFi.

Fronius settings:

  • Modbus TCP: port 502

  • SunSpec: int+SF

  • Control via Modbus: enabled

  • Country setup: 50 Hz MicroGrid
    This is also visible on the Fronius display.

Now to my problem:

I cannot find the Fronius in the VRM device list, and it is also not displayed on the dashboard.

What I have already configured/checks:

  • In VRM → Remote Console → Settings → PV Inverters, the IP address 192.168.178.160 is entered, assigned to AC-out-1 L1, and “Show” is enabled.

  • In VRM → Remote Console → Settings → Modbus TCP, the IP address and port 502 are entered with device/unit ID 1.

  • Calling the following Fronius API endpoint:

http://192.168.178.160/solar_api/v1/GetInverterRealtimeData.cgi?Scope=System

returns this data:

{
   "Body" : {
      "Data" : {
         "DAY_ENERGY" : {
            "Unit" : "Wh",
            "Values" : {}
         },
         "PAC" : {
            "Unit" : "W",
            "Values" : {}
         },
         "TOTAL_ENERGY" : {
            "Unit" : "Wh",
            "Values" : {}
         },
         "YEAR_ENERGY" : {
            "Unit" : "Wh",
            "Values" : {}
         }
      }
   },
   "Head" : {
      "RequestArguments" : {
         "DeviceClass" : "Inverter",
         "Scope" : "System"
      },
      "Status" : {
         "Code" : 0,
         "Reason" : "",
         "UserMessage" : ""
      },
      "Timestamp" : "2026-05-24T11:21:52+02:00"
   }
}

The Fronius is definitely feeding into the system, because the PV power is correctly reducing the AC loads. So electrically it seems to be working, but it is not shown in VRM or the device list.

Do you have any ideas what could be wrong or what else I should check?

Thanks in advance for your help.

Additional note, which might be relevant:

The system was previously connected to the grid, and the Fronius was configured for a normal 50 Hz grid setup and feeding directly into the system. At that time it was visible in the VRM device list. After converting the system to the off-grid setup, I removed all previous Fronius entries from the configuration.

PPS:

I recently updated my Datamanager Firmware to the newest version, maybe that is the problem?