# Reading system LED states and physical diagnostics on PFC100 (750-8112)

**URL:** https://www.wago.community/t/lecture-des-etats-led-systeme-et-diagnostics-physiques-sur-pfc100-750-8112/2705
**Category:** CODESYS
**Created:** [April 30, 2026, 9:55am UTC](https://www.wago.community/t/lecture-des-etats-led-systeme-et-diagnostics-physiques-sur-pfc100-750-8112/2705 "2026-04-30T09:55:15Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![jahedul](https://avatars.discourse-cdn.com/v4/letter/j/e47774/32.png) [@jahedul](https://www.wago.community/u/jahedul)
#### Post date: [April 30, 2026, 9:55am UTC](https://www.wago.community/t/lecture-des-etats-led-systeme-et-diagnostics-physiques-sur-pfc100-750-8112/2705/1 "2026-04-30T09:55:15Z")

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**Hello everyone,**

As a user of the **WAGO 750-8112** automation system, I would like to set up detailed monitoring of my CPU’s physical status.

My goal is to display the real-time status of the physical interfaces in my application (HMI/Supervision), specifically:

- The **system LEDs** (SYS, I/O, CAN, etc.).

- The **Link/Act** status of the Ethernet ports.

- Any internal diagnostics (temperature, battery/goldcap status).

**My questions for the community:**

1. Is there a specific library (such as _WagoAppDiagnostic_ or _WagoAppSystem_) that allows retrieving the status (color/flashing) of the SYS and I/O LEDs?

2. How can I access the diagnostic variables of the network interfaces to determine if a link is physically “Up” or “Down” outside of the application protocol?

3. Do I need to use system calls (SysProcess), or are there ready-to-use FBs (Function Blocks) available in e!COCKPIT or CODESYS V3.5?

If you have a code example or documentation on mapping these internal registers, I would greatly appreciate it!

Thank you in advance for your help.

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### Author: ![ChristianBelote](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/christianbelote/32/1762_2.png) [@ChristianBelote](https://www.wago.community/u/ChristianBelote)
#### Post date: [May 4, 2026, 9:09pm UTC](https://www.wago.community/t/lecture-des-etats-led-systeme-et-diagnostics-physiques-sur-pfc100-750-8112/2705/2 "2026-05-04T21:09:57Z")

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Hi @jahedul ,

One option for this is to use the **WagoAppConfigTool** library. I have used this to pull some of the controller’s internal diagnostic/configuration information directly into a CODESYS application.

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/5/564c62e13717d82ff415c8bf2d6bcb6c1c1da2e0.png)

For example, the library can be used with calls such as:

`./get_led_config_state IO`

to read the configured state/color of the I/O LED, and:

`./get_actual_eth_config X1 cable-state`  
`./get_actual_eth_config X2 cable-state`

to check the physical Ethernet link/cable state of the X1 and X2 ports.

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/9/9fbb797b5084a749932d7daf4877dacc6281db98.png)

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/7/73ab2907ea3813f9a5a998eb5f00ec03233f8aee.png)

I attached a screenshot showing a simple test where I am calling the ConfigTool function blocks and storing the results in string variables.

I also made a separate forum post with more detail on using the library here:

[https://www.wago.community/t/howto-using-wagoappconfigtool-library-for-accessing-controller-diagnostics/2333](https://www.wago.community/t/howto-using-wagoappconfigtool-library-for-accessing-controller-diagnostics/2333)