---
title: XC5 Theory of Operation
slug: hardware/xc5-theory-of-operation
docTags: 
createdAt: 2025-03-11T07:10:54.522Z
---

This section describes how specific components operate on the XC2055 and XC4055

# On-Board LEDs

The four on-board LEDs have the following indicators:

| **LED**                                                                                                                                                                | **Indication**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Green power (**Pwr**)                                                                                                                                                  | Displays when the board is powered up and not in reset mode. Flashes during firmware update process.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Green file-system activity (**Bsy**)                                                                                                                                   | Flashes any time there is file-system activity (on any storage device)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Blue (**WiFi**)                                                                                                                                                        | Illuminates when WiFi is connected and flashes when searching for a connection                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Red status (**Err**)                                                                                                                                                   | Flashes a certain number of times to indicate which error is occurring. The flash codes are described below:<br />2: Unspecified error<br />3: Network recovery script is preparing to run on a device configured for network recovery<br />4: No upgrade file found<br />5: Failed to load kernel module<br />- 6: Board is not capable of running the current firmware version<br />- 7: A piece of on-board hardware is not working correctly<br />- 8: Problem related to the storage device (either the USB drive or MicroSD card)<br />- 9: Problem related to the registry/NAND<br />- 10: The autorun script encountered a load/run error<br />- 11: WiFi-related error<br />- 12: Unable to find bootable image |
| A solid error light is displayed during the micro-controller update in BOS 9.0.36. Updating from an earlier OS version to BOS 9.0.36 or later will trigger this light. |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |

# On-Board Switch / SVC Button

The SVC button is connected to the GPP\_D6 GPIO on the processor. The RESET button is also sent to the PMIC (support micro), which when the button is asserted for four seconds will initiate a hard reset.

# Reset Switch / GPIO Button

The RESET button is connected to the GPP\_D5 GPIO on the processor. The RESET button is also sent to the PMIC (support micro), which when the button is asserted for four seconds will initiate a hard reset.

# microSD Slot

The XC2055 and XC4055 have one MicroSD slot. High density memory cards with a capacity of up to 2TB, and SDR104 and microSC3.0 UHS-I ultra-high speed memory cards, are supported

# Wireless Module

The XC2055 and XC4055 both have a dual antenna connection to allow users to install a BrightSign wireless module without disassembling the unit. BrightSign modules are configured to work with 802.11.N or 802.11.AC access points. This connection has a Bluetooth option.