# Ignition 7.9.6 and ctypes -- missing windll

**URL:** <https://forum.inductiveautomation.com/t/ignition-7-9-6-and-ctypes-missing-windll/17356>\
**Category:** Module Development\
**Tags:** ignition79\
**Created:** [March 13, 2018, 10:44pm UTC](https://forum.inductiveautomation.com/t/ignition-7-9-6-and-ctypes-missing-windll/17356 "2018-03-13T22:44:57Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Norman.Davie](https://avatars.discourse-cdn.com/v4/letter/n/34f0e0/32.png) [@Norman.Davie](https://forum.inductiveautomation.com/u/Norman.Davie)\
**Post date:** [March 13, 2018, 10:44pm UTC](https://forum.inductiveautomation.com/t/ignition-7-9-6-and-ctypes-missing-windll/17356/1 "2018-03-13T22:44:58Z")

</div>

I’m trying to load a dynamic linked library that has a few standard c (cdecl) library calls – a few calls but LOTS of code behind them.

Jython v2.5.2 apparently supports this, but I cannot get ignition to load a dynamic library.

One of the things I noticed is windll is missing in ctypes.

Docs regardin loading DLL in jython:  
[Jython ctypes documentation](http://www.jython.org/docs/library/cpython_only/ctypes-R.html)

Do I need to create a JNI to load a library in Ignition?

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [March 13, 2018, 11:04pm UTC](https://forum.inductiveautomation.com/t/ignition-7-9-6-and-ctypes-missing-windll/17356/2 "2018-03-13T23:04:27Z")

</div>

> [@Norman.Davie](#):
>
> Do I need to create a JNI to load a library in Ignition?

If you can get ctypes in Jython working on your own, that would be fine, but we don't support it. I thought the Jython ctypes implementation was only partially complete.

Creating a module and interfacing with your DLL using JNI or JNA would be the "supported" approach.

---

<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [March 14, 2018, 2:39am UTC](https://forum.inductiveautomation.com/t/ignition-7-9-6-and-ctypes-missing-windll/17356/3 "2018-03-14T02:39:16Z")

</div>

Don’t expect ctypes to work in jython. That documentation was copied over from [python.org](http://python.org) and wasn’t properly pruned. It even has “new in 2.6” statements for v2.5.2. It doesn’t – _cannot_ – work.