Fronius State 516 — Datamanager Error

What Does This Error Mean?

Fronius State 516 indicates a fault with the Datamanager card inside the inverter — the card that handles Wi-Fi, Ethernet, and Solar.web cloud communication. The solar system continues to produce power normally — only remote monitoring is affected. A Datamanager reboot or card replacement restores communication.

Affected Models

Fronius Primo with Datamanager 2.0
Fronius Symo with Datamanager 2.0
Fronius Galvo with Datamanager 2.0
Fronius SnapINverter models

Common Causes

Datamanager card firmware update failed or was interrupted
Wi-Fi credentials changed on the home router and the Datamanager has the old password
Datamanager card hardware fault after a power surge
IP address conflict on the home network
Weak Wi-Fi signal causing the Datamanager to lose connection repeatedly until it locks up

How to Fix It

Power cycle the inverter to reboot the Datamanager.

Switch off the solar AC isolator and the DC isolator at the inverter. Wait 2 minutes for the capacitors to discharge. Turn the DC isolator back on, then the AC isolator. The Datamanager takes approximately 5 minutes to boot and reconnect to Solar.web.
Check whether the Datamanager appears on your network.

On a computer connected to the same Wi-Fi or LAN, open a browser and go to http://fronius.local or try the inverter's IP address (check your router's device list). If the page loads, the Datamanager is running and a Solar.web reconnection issue is more likely than a hardware fault.
Re-enter Wi-Fi credentials if the router was changed.

If your home Wi-Fi router, SSID, or password was changed recently, the Datamanager still has the old credentials. Connect a laptop to the Datamanager's own temporary Wi-Fi hotspot (named 'Fronius_XXXXXXXX') and use the setup wizard to enter the new Wi-Fi details.
Check the Solar.web portal for the inverter's last online time.

Log in to solarweb.com and check when the inverter last reported data. If it was many months ago, the Datamanager may have been offline since a router change or firmware update. The production data since then is stored in the inverter and will upload once connectivity is restored.

When to Call a Professional

If the Datamanager does not recover after a full power cycle and does not appear on the network, the card may need to be replaced. This requires a licensed electrician to open the inverter.

Frequently Asked Questions

Does State 516 stop my solar panels from producing power?

No. The Datamanager only handles monitoring and communication. The power electronics that convert DC to AC continue operating normally. Your solar system is still producing even when State 516 is active.

Where is the Datamanager card located in a Fronius inverter?

The Datamanager is a plug-in card inside the inverter's communication compartment — a small door on the front or bottom of the unit. It can be removed and reinserted without the inverter being live, but the enclosure must be opened by a licensed electrician.