# LEDs

The VPU has eight LEDs for **POWER**, **STATE**, **PORT[0...5]** that light up red or green depending on the status of the system.

![Photograph of the VPU with green LEDs ON](./img/vpu_leds.jpeg)

## Power LED

| LED   | Red | Green          | Description                     |
| ----- | --- | -------------- | ------------------------------- |
| Power | N/A | VPU powered up | The VPU is powered up with 24V. |

## State LED

| LED   | Red       | Green     | Description                                                   |
| ----- | --------- | --------- | ------------------------------------------------------------- |
| State | OFF       | OFF       | The VPU is not powered up.                                    |
|       | OFF       | Blinking  | Initialization.                                               |
|       | OFF       | ON        | Operate.                                                      |
|       | Blinking  | OFF       | Critical error.                                               |
|       | ON        | OFF       | Major error.                                                  |
|       | Blinking* | Blinking* | Software update. <br>*alternate blinking of green and red LED |

## Port LEDs

| LED            | Green                                                   | Description                                                                                                                                                                    |
| -------------- | ------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Local port LED | ON                                                      | The VPU is operating and the port is functional (camera head detected).                                                                                                        |
|                | Blinking                                                | Critical or major error related to this port.                                                                                                                                  |
|                | OFF                                                     | If the VPU is operating and the port LED is OFF, the port is not functional (no camera head is detected). <br>Or, the VPU is not powered up. <br> Or, software update ongoing. |
| Port LED array | "Knight rider": port LEDs blinking one after the other. | Boot-up or initialization sequence.                                                                                                                                            |
|                | Synchronous blinking                                    | Critical or major system-wide error.                                                                                                                                           |

## Ethernet LEDs

Each Ethernet port has two LEDs. The leftmost one, LED 0 below, is yellow. The rightmost one, LED 1 below, is green. They behave the same for both port.

| LED            | State    | Description                                                                             |
| -------------- | -------- | --------------------------------------------------------------------------------------- |
| LED 0 (yellow) | OFF      | The VPU is not powered-up. <br>Or, boot-up sequence ongoing.                            |
|                | Blinking | Initialization sequence. <br>Or, the VPU is operating. <br>Or, software update ongoing. |
| LED 1 (green)  | OFF      | The VPU is not powered-up. <br>Or, boot-up sequence ongoing.                            |
|                | Blinking | Initialization sequence. <br>Or, the VPU is operating. <br>Or, software update ongoing. |