# Page Exception fault

**URL:** <https://community.br-automation.com/t/page-exception-fault/6389>\
**Category:** B&R Software & Runtime\
**Tags:** automation-studio, automation-runtime, sdm\
**Created:** [March 28, 2025, 4:06am UTC](https://community.br-automation.com/t/page-exception-fault/6389 "2025-03-28T04:06:30Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![veeresh.suranagi](https://avatars.discourse-cdn.com/v4/letter/v/FF8800/32.png) [@veeresh.suranagi](https://community.br-automation.com/u/veeresh.suranagi)\
**Post date:** [March 28, 2025, 4:06am UTC](https://community.br-automation.com/t/page-exception-fault/6389/1 "2025-03-28T04:06:30Z")

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How to find exactly which line of the PLC program causes page exception fault? using fault details.

Page exception fault description find below.

 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/b/bd0b939fd199cfaa8611fe12c8d022d433bcfdb7.png)  
 ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/2/2cb565e639222b8fc61e13e846867a12a6ce47c1.png)

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**Author:** ![alexander.hefner](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/alexander.hefner/32/111_2.png) [@alexander.hefner](https://community.br-automation.com/u/alexander.hefner)\
**Post date:** [March 28, 2025, 6:00am UTC](https://community.br-automation.com/t/page-exception-fault/6389/2 "2025-03-28T06:00:28Z")

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Hi,

Not in every case it’s possible to detect the right line of code causing the pagefault using the logger, but please check the backtrace.  
Details about can be found in the excellent thread from Andrew here:

> [@Troubleshooting Page Faults](https://community.br-automation.com/t/troubleshooting-page-faults/494):
>
> 1 Overview 1.1 What is a page fault? The processor throws an exception to the operating system if it tries to access an invalid or protected memory location. The B&R operating system logs this type of serious memory violation as a page fault (error 25314). 1.2 What can cause a page fault? Processor memory can become invalid as a result of programming errors such as: Null or incorrect pointer Division by zero Accessing an index of an array which does not exist (i.e. the 11th element of a 10 el…

Best regards.

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**Author:** ![carl.hidestal](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/carl.hidestal/32/4370_2.png) [@carl.hidestal](https://community.br-automation.com/u/carl.hidestal)\
**Post date:** [March 28, 2025, 8:55am UTC](https://community.br-automation.com/t/page-exception-fault/6389/3 "2025-03-28T08:55:08Z")

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Hello,

Create a wait := TRUE variable in the init routine of your first executed program. Then download the project and enter debugger mode. Set a breakpoint on the wait variable.

In debugger mode you toggle the wait variable to false and step through your code until you get the page fault. Then you will know what line crashes the program.

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**Author:** ![system](https://europe1.discourse-cdn.com/brcommunity/original/1X/a202d64f0f03e22a662ed33fbbca6879f1efb794.jpeg) [@system](https://community.br-automation.com/u/system)\
**Post date:** [May 29, 2025, 3:42pm UTC](https://community.br-automation.com/t/page-exception-fault/6389/4 "2025-05-29T15:42:30Z")

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