# Persistent Retain Variables Not Visible in Online View (PFC100 + CODESYS)

**URL:** <https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374>\
**Category:** CODESYS\
**Tags:** pfc100\
**Created:** [October 23, 2025, 9:57am UTC](https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374 "2025-10-23T09:57:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![JasperClauwaert](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@JasperClauwaert](https://www.wago.community/u/JasperClauwaert)\
**Post date:** [October 23, 2025, 9:57am UTC](https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374/1 "2025-10-23T09:57:21Z")

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Hi everyone,

I’m working on a WAGO PFC100 with CODESYS. During development everything worked fine, but in the final stage I set several variables to `PERSISTENT RETAIN`.

When I go online, **most of these persistent variables cannot be monitored**. Instead, I see:

```auto
<Value of the expression cannot be retrieved>

```

Interestingly, a few variables do show their values correctly, but the majority do not.

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/3/3f0b62908e476a255076e9591e205976df373889.png)

- The variables are not used as pointers or in any unusual way.

- The application compiles and runs without errors.

Has anyone experienced this before? Is this a known issue with PFC100 or CODESYS? Any ideas on what could cause this behavior?

Thanks in advance!  
Jasper

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<div class="post-metadata">

**Author:** ![AdamReeve](https://sea2.discourse-cdn.com/flex016/user_avatar/www.wago.community/adamreeve/32/59_2.png) [@AdamReeve](https://www.wago.community/u/AdamReeve)\
**Post date:** [October 23, 2025, 1:31pm UTC](https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374/2 "2025-10-23T13:31:14Z")

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After changing your declaration to VAR PERSISTENT RETAIN, did you also add a Persistent Variables object to your project as step 2? And then step 3 is to open that object in a tab, right-click, and select “Add all Instance Paths”?

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/5/5bbce71253d998ebc007b793b3024f371a4ebd08.png)

 ![image](https://us1.discourse-cdn.com/flex016/uploads/wago/original/2X/e/e5ad3b99eb4eb6916ae6977937b8a174e3e0b97b.png)

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<div class="post-metadata">

**Author:** ![JasperClauwaert](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@JasperClauwaert](https://www.wago.community/u/JasperClauwaert)\
**Post date:** [October 23, 2025, 2:21pm UTC](https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374/3 "2025-10-23T14:21:21Z")

</div>

Yes, I did. I also tested the persistent variables with a power cycle, and they work as expected. The issue is that I cannot monitor these variables in the online view, which is important for debugging purposes.

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<div class="post-metadata">

**Author:** ![JasperClauwaert](https://avatars.discourse-cdn.com/v4/letter/j/b5a626/32.png) [@JasperClauwaert](https://www.wago.community/u/JasperClauwaert)\
**Post date:** [October 24, 2025, 2:59pm UTC](https://www.wago.community/t/persistent-retain-variables-not-visible-in-online-view-pfc100-codesys/2374/4 "2025-10-24T14:59:16Z")

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I contacted WAGO support, and they confirmed this is a CODESYS bug. Whenever a persistent 64-bit variable is monitored on a 32-bit controller, the online list cannot display the values correctly.

The solution is either:

- Avoid monitoring any 64-bit persistent variables, or

- Change them to 32-bit or smaller types.

Important to note: the variables do hold their correct 64-bit values in the PLC. The issue is only with how CODESYS displays them.