---
title: "system.serial.writeBytes"
description: "Write a byte[] to a serial port."
---

# system.serial.writeBytes

> Write a byte[] to a serial port.

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

## Description
## Client Permission Restrictions
This scripting function has no [Client Permission](projects\project-properties\project-properties.md#client---permissions) restrictions.

## Syntax
`system.serial.writeBytes(port, toWrite)`

### Parameters

|Type|Parameter|Description|
|--|--|--|
|String| `port` | The previously configured serial port to use.|
|byte[]| `toWrite` | The byte[] to write.|
### Returns
Nothing
### Scope
All