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
:Admin
credentialsGEN24
:Technician
account orCustomer
account 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:
12345678
Access web interface at
192.168.250.181
(or assigned IP)
Modbus Configuration
Log in with
Admin
credentialsNavigate to
Modbus
settingsConfigure the following:
Set "Data export via Modbus" to
tcp
Change "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 Editor
Set "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
192.168.250.181
Access
System
→Support
Enable both:
Remote Access
Support User
Modbus Configuration (Technician Access)
Navigate to
Communication
→Modbus
Enable "Control via Modbus TCP"
Set
String Control Address-Offset
to101
in the inverter settings (or102
for the second inverter), but always use1
(or2
) in the configurator or app.Set "SunSpec Model Type" to
float
Enable
Allow Control
Control Priority Setup
Access
Safety and Grid Regulations
Set
Modbus Control
to 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
GEN24
models, 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.