# Quick feature highlight: \`system.serial.port\` function

**URL:** <https://forum.inductiveautomation.com/t/quick-feature-highlight-system-serial-port-function/36404>\
**Category:** Ignition Early Access\
**Created:** [July 6, 2020, 7:19pm UTC](https://forum.inductiveautomation.com/t/quick-feature-highlight-system-serial-port-function/36404 "2020-07-06T19:19:18Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [July 6, 2020, 7:19pm UTC](https://forum.inductiveautomation.com/t/quick-feature-highlight-system-serial-port-function/36404/1 "2020-07-06T19:19:18Z")

</div>

New in 8.0.15, we’ve added a `system.serial.port` function that returns a “context manager” object that’s useful for scripting. Briefly, context managers are useful with the `with` statement ([PEP 343](https://www.python.org/dev/peps/pep-0343/)) for automatic handling of resources. The new function acts as a complement to the existing functions - no existing code is deprecated, there’s just a new syntax that makes things a little cleaner to write.

So, with the exist functions, you first have to configure the serial port, then specifically open it, then perform your operations on that open port, then close it.

```python
system.serial.configureSerialPort("COM1", bitRate=system.serial.BIT_RATE_9600)
system.serial.openSerialPort("COM1")
line = system.serial.readLine("COM1", 60000)
system.serial.closeSerialPort("COM1")

```

Notice the repetition of the `COM1` constant.  
The chief advantage of the new style is avoiding repetition; the `system.serial.port` function accepts all the same arguments as `system.serial.configureSerialPort`, but once you’ve used it you don’t have to manually open or close ports, nor call fully prefixed functions to interact with the port.  
The above example becomes, with the new syntax:

```python
with system.serial.port("COM1", bitRate=system.serial.BIT_RATE_9600) as port:
    line = port.readLine(60000)

```

The context manager returned by `system.serial.port` itself returns a `SerialPort` object, with special “partial” implementations of the `system.serial` functions - so `port.readLine` is valid in the above, as well as `port.write`, `port.sendBreak`, etc. There’s no need (and indeed, no capability) to specify a different port with this syntax.

The other chief advantage of the `with` statement is that even if an exception is thrown inside your code, the serial port will _always_ be closed; it’s equivalent to a `try/finally` block in Python.