---
title: "system.serial.readBytesAsString"
description: "Read numberOfBytes bytes from a serial port and convert them to a String."
---

# system.serial.readBytesAsString

> Read numberOfBytes bytes from a serial port and convert them to a String.

This function is used in **Python Scripting**.

## Description
Read numberOfBytes bytes from a serial port and convert them to a String. If a specific encoding is needed to match the source of the data, use [system.serial.readBytes](system-serial-readBytes.md) and use the desired encoding to decode the byte array returned.

## Client Permission Restrictions
This scripting function has no [Client Permission](../../../ignition-modules/vision/vision-project-properties/vision-project-properties.md#vision-permissions-properties) restrictions.

## Syntax
`system.serial.readBytesAsString(port, numberOfBytes, [timeout], [encoding])`

### Parameters
Type | Parameter | Description 
------- | ------- | ------
String| `port` | The previously configured serial port to use.
Integer| `numberOfBytes` | The number of bytes to read.
Integer| `timeout` | Maximum amount of time, in milliseconds, to block before returning. Default is 5000. [optional]
String| `encoding` | Encoding to use when constructing the string. Defaults to the platform's default character set. [optional]

### Returns
**String** - A String created from the bytes read.

### Scope
Gateway, Vision Client, Perspective Session

## The Encoding Parameter
The encoding parameter can be used to decode a string with any of the possible encoding character sets that are available. By default, the following character sets are provided by [the Java platform](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/nio/charset/StandardCharsets.html) (dash characters and underscores are interchangeable). Dashed examples are shown below:

* ISO-8859-1
* US-ASCII
* UTF-16
* UTF-16BE
* UTF-16LE
* UTF-8

## Code Example
```python title="Code Snippet"
# This example will read a specified number of bytes as a String from a port called "COM1".
port = "COM1"
numberOfBytes = 2
 
system.serial.readBytesAsString(port,numberOfBytes)
```