The first version of the device has no LED.
Slow blinking (once per second)No inverter is responding. This is normal at night; during the day, check the RS-485 and the inverter settings.
Double blinkNo internet. Check the router.
Fast blinking (twice per second)No network connection. Check the Ethernet cable or set up WiFi.
Very fast blinkingStarting up or updating software. Wait and don't cut the power.
OffThe device has no power.