# Wago custom firmware build and C module for runtime

**URL:** https://www.wago.community/t/wago-custom-firmware-build-and-c-module-for-runtime/2312
**Category:** Hardware and Linux
**Created:** [September 25, 2025, 5:50pm UTC](https://www.wago.community/t/wago-custom-firmware-build-and-c-module-for-runtime/2312 "2025-09-25T17:50:38Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![FPawlak](https://avatars.discourse-cdn.com/v4/letter/f/f6c823/32.png) [@FPawlak](https://www.wago.community/u/FPawlak)
#### Post date: [September 25, 2025, 5:50pm UTC](https://www.wago.community/t/wago-custom-firmware-build-and-c-module-for-runtime/2312/1 "2025-09-25T17:50:38Z")

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Hi everyone.

I haven’t played with custom pfc-firware-sdk yet - [GitHub - WAGO/pfc-firmware-sdk-G2: Firmware SDK for PFC200-G2 family](https://github.com/WAGO/pfc-firmware-sdk-G2)

But I wonder if it is possible to implement Codesys FB module in C code. I know that it is possible in Codesys e.g. with Raspberry SL licence.

So following those guides, I was able to implement FB module in C and upload it with Codesys project to Raspberry. I also tried the same way to upload it to PFC 200 with normal Wago firmware. But I was unsuccessful. I think it is due to the requirements of CODESYS Control Extension Package in runtime.

But I hope that with manual firmware building I can extend the firmware and already include in it my custom C module, so it won’t have to be uploaded with Codesys project to PLC. I mean that I will have to only mark FB module as ‘external implementation’

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/0/01ba7a0e863f58fa0e6389b4cc682fc668cc52dc.png)

Can somebody say if I am correct or wrong? I hope that somebody has already tried this and has some knowledge of whether it is possible or not.

Thanks a lot for any help

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<div class="post-metadata">

### Author: ![FPawlak](https://avatars.discourse-cdn.com/v4/letter/f/f6c823/32.png) [@FPawlak](https://www.wago.community/u/FPawlak)
#### Post date: [September 25, 2025, 5:52pm UTC](https://www.wago.community/t/wago-custom-firmware-build-and-c-module-for-runtime/2312/2 "2025-09-25T17:52:28Z")

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Sorry for second post, but I was unable to paste more than two links. I’m refering to this codesys functionality

> **[CODESYS Group](https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_integrating_c_code.html)**

> **[CODESYS Group](https://content.helpme-codesys.com/en/CODESYS%20Control/_rtsl_extension_extension_sdk.html)**