---
title: "How to: Use Serial with Edge IO"
slug: "how-to-use-serial-with-edge-io-1"
updated: 2022-09-30T18:14:22Z
published: 2022-09-30T18:14:22Z
---

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

# Use Serial with Edge IO

## How to: Use Serial with Edge IO

*A setup guide on using Serial with Edge IO*

In this article, you will learn the technical details of using serial on Edge IO.

Edge IO supports serial connections over USB, RS-232, or RS-485. This article will cover the hardware connections and software identifiers for each connection.

To learn how to communicate this serial data to Tulip, please see our other support articles:

**[Guide on Generic Serial Driver](https://support.tulip.co/docs/how-to-use-the-generic-serial-driver-on-io-gateway)

**[Guide on Node-RED setup with Serial](https://support.tulip.co/docs/how-to-use-serial-with-node-red-1)

## Connect using USB

To use serial over USB, you will need a serial device that connects over USB, or a serial-to-USB adapter (for example, a RS232-to-USB adapter cable, or RS485-to-USB adapter).

The Edge IO has six USB ports; you can plug your USB cable into any USB port.

While plugging into USB, the identifiers will be assigned in order of being plugged in:

- 1st USB port plugged in: `/dev/ttyUSB0`
- 2nd USB port plugged in: `/dev/ttyUSB1`
- 3rd USB port plugged in: `/dev/ttyUSB2`

#### **`...`**

## Connect using RS-232/RS-485

The Edge IO also has RS-232 and RS-485 ports.

The identifier for the serial device:

- RS-232: `/dev/ttyS1`
- RS-485: `/dev/ttyS2`

*Note: RS-232 uses a standard DB9 connector, and supports RTS/CTS, but not DCD/DTR/DSR. RS-485 is half-duplex.*

#### Edge IO Port Diagram:

![](https://cdn.document360.io/7c6ff534-cad3-4fc8-9583-912c4016362f/Images/Documentation/How%20to%3A%20Use%20Serial%20with%20Edge%20IO_456206497.png)

![How to: Use Serial with Edge IO](https://cdn.document360.io/7c6ff534-cad3-4fc8-9583-912c4016362f/Images/Documentation/How%20to%3A%20Use%20Serial%20with%20Edge%20IO_458551354.png)

*See above the RS-232 and RS-485 pinouts.*