Fronius inverters can be configured for Modbus TCP in two different ways, depending on your model. This guide covers both standard Fronius inverters with Datalogger and GEN24 models.
Prerequisites
Access level requirements vary by model:
Standard Fronius with
Datalogger:AdmincredentialsGEN24:Technicianaccount orCustomeraccount with support assistanceNetwork connectivity
Web browser
Configuration for Standard Fronius with Datalogger
Initial Connection
Connect to inverter's WiFi access point:
Locate network name containing
Datalogger ID(240.xxxxx or 239)Use default WiFi password:
12345678Access web interface at
192.168.250.181(or assigned IP)
Modbus Configuration
Log in with
AdmincredentialsNavigate to
ModbussettingsConfigure the following:
Set "Data export via Modbus" to
tcpChange "Sunspec Model type" to
float
Save configuration
Note that the modbus configuration will affect the type of the inverter when adding the it to the gateway. There are some options: Fronius, Fronius SF and SunSpec Compatible when adding the device. These must correspond to your Modbus settings in your inverter configuration page.
Control Priority Setup
Access
DNO EditorSet "Controlling via Modbus" to priority 1
Adjust priority order if needed
Save changes
Configuration for GEN24 Series
Initial Access Setup
Connect to inverter WiFi (password:
12345678)Navigate to
192.168.250.181Access
System→SupportEnable both:
Remote AccessSupport User
Modbus Configuration (Technician Access)
Navigate to
Communication→ModbusEnable "Control via Modbus TCP"
Set
String Control Address-Offsetto101in the inverter settings (or102for the second inverter), but always use1(or2) in the configurator or app.Set "SunSpec Model Type" to
floatEnable
Allow Control
Control Priority Setup
Access
Safety and Grid RegulationsSet
Modbus Controlto highest prioritySave all changes
Important Notes
Password management varies by model type
Multiple inverters require individual configuration
Document settings for each unit
Troubleshooting
Access Issues
For login problems:
Contact support with model and serial numbers for password resets
Verify network settings
Double-check IP addresses
Configuration Problems
If experiencing issues:
For
GEN24models, consult installer or Fronius supportVerify all settings are saved properly
Check network connectivity
Testing connectivity (advanced)
After configuring Modbus TCP on your Fronius inverter, it's important to verify that the connection is working properly. You can follow our testing guide to confirm the connection. For Fronius inverters, use the default Modbus port 502. The Unit ID is typically set to 1, but you might need to check your specific configuration if this doesn't work. Remember that both standard and GEN24 models use the same Modbus TCP port and Unit ID conventions.