---
title: "Connecting to a UART Serial Header"
slug: "uart-serial-header"
updated: 2025-10-31T17:27:55Z
published: 2025-10-31T17:27:55Z
canonical: "docs.telosalliance.com/uart-serial-header"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.telosalliance.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Connecting to a UART Serial Header

## Scope

The Infinity CPU Board is used on a number of products, including Telos Infinity, Axia IQx, iQs, 25-Seven PDM II, and some Linear Acoustic products.

> [!WARNING]
> Some products that don’t use this specific board use the same Serial UART header. As of this writing, the xNode2 uses the same serial connection.

## Description

This board has a serial UART header, which is helpful for advanced troubleshooting. This port can not be used for configuration, etc. If you are reading this doc hoping to find configuration or other information from this port, move along. There is nothing to see here.

This port, labeled J6 UART, is located along the long edge of the board (opposite the Ethernet connectors), next to the MicroSSD slot.

## Connection

> [!WARNING]
> The serial line voltages on this board are "TTL level", not the more standard "RS232 level." You need an "active" cable for this. A standard serial cable or even a USB RS323 adapter will not work. You need some kind of active USB to TTL Serial 3.3V UART Converter Cable.

The pinouts are defined as follows (note: pin 1 is closest to the edge of the board):

- Pin 1 - +3.3V (leave unconnected)
- Pin 2 - Transmit (generally White)
- Pin 3 - Receive (generally Green)
- Pin 4 - Ground (generally Black)

> [!CAUTION]
> NOTE, Pin 1 has +3V DC; unless instructed otherwise, do NOT connect anything to this pin. Please be cautious connecting your serial port cable to not damage your device or short out this board. **Shorted boards or damage as a result of misuse are not covered as a warranty repair.**

![](https://files.helpdocs.io/ooa6cyzgdv/articles/c6zpit1jdy/1639934145892/image.png)

The header number will vary by product

## Image of the entire board for orientation purposes

> [!WARNING]
> Cables and other components were removed for clarity.

![](https://files.helpdocs.io/ooa6cyzgdv/articles/c6zpit1jdy/1648491954624/image.png)

## Close-up of the J6 UART header

![](https://files.helpdocs.io/ooa6cyzgdv/articles/c6zpit1jdy/1648492025401/image.png)

## Properly connected cable

> [!CAUTION]
> Note, no connection to Pin 1

![](https://files.helpdocs.io/ooa6cyzgdv/articles/c6zpit1jdy/1648492136528/image.png)

### Terminal Settings

Adjust your settings in your terminal program as shown here;

- Baud Rate - 115,200
- Data Bits - 8
- Stop Bits - 1
- Parity - None
- Flow Control - None

![](https://files.helpdocs.io/ooa6cyzgdv/articles/c6zpit1jdy/1639934744750/image.png)