---
title: "system.serial.closeSerialPort"
description: "Closes a previously opened serial port."
---

# system.serial.closeSerialPort

> Closes a previously opened serial port.

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

## Description
Closes a previously opened serial port. Returns without doing anything if the named serial port is not currently open. Will throw an exception if the port is open and cannot be closed.

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

## Syntax
`system.serial.closeSerialPort(port)`

### Parameters

|Type|Parameter|Description|
|--|--|--|
|String| `port` | The name of the serial port, e.g., "COM1" or "dev/ttyS0".|
### Returns
Nothing
### Scope
All