Horizon has two independent LED indicators. STATUS provides insight to overall device operation and LINK to LOS link connection.

STATUS LED

Pattern	Meaning
🟢 Solid Green	Power good (normal)
🔴 Blinking Red	Bootloader mode (abnormal during operation)
🟡 Flashing Amber	Firmware update in progress — do not unplug the device

LINK LED

Pattern	Meaning
🟢 Blinking Green	LOS link connected
🔴 Blinking Red	LOS link lost

For the full connector and port callout key, see Hardware Description.