badwithPLCs (Customer) asked a question.

September 25, 2026 at 12:30 PM
P2000 E01005 System Restart error, PLC put in stop

Hello,

I have a P2-550 PLC that is intermittently returning a "E01005" error and putting the PLC in stop mode. I have not been able to find much documentation on this error. I have not been able to find any indication of what is causing the error. It also seems to me that it should not be putting the PLC in stop mode. I am using the latest firmware version 1.3.0.6. I have attached the pac_history.txt file, if there is any other files that would be helpful for diagnosis I can add more.

 

Thanks!

  • 5 answers
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  • ADC_TechnologyGroup_06 (AutomationDirect)

    Help Topic P233 on System Error Codes has a table which includes the following information on E01005 which is a critical error and puts the CPU into Stop mode:

    • Cause: The CPU has unexpectedly restarted. The most common cause of this error is due to a power fluctuation (power spike, brown out, noise). It can also occur due to a soft-reset caused by a hardware watchdog timeout.
    • Error Action: Critical
    • Solution: Power cycle the system and/or toggle the run/stop switch to stop then back to run. If error occurs again, double check the power feeding the CPU.

     

    Can you send or attach the SystemReport.zip file which would contain more information for us to examine if there's something beyond watchdog timeout or power fluctuations?

     

    If you check the Maximum Scan Interval field in the CPU's Hardware Config and compare that to your Avg Scan Interval [x100=μsec] system tag in Data View, then you could confirm if you're close to a watchdog timeout which could be triggering the issue.

     

    Thanks!

     

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    • badwithPLCs (Customer)

      Here is the system report for that plc.

      Thanks,

      Dylan Epperson

      • badwithPLCs (Customer)

        posted a file.
        • Unknown file type
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      • ADC_TechnologyGroup_06 (AutomationDirect)

        @badwithPLCs (Customer)​ The System Report file was deleted. If you don't want to post it here, then feel free to PM it to me. You can do that by clicking on my username ADC_TechnologyGroup_06 and then on that page there's a Message button and an option to attach files. Thanks!

  • K Price (Customer)

    I agree that the PLC is going onto stop mode is due to power fluctuation (power spike, brown out, noise). High heat could also cause problems, but you did not mention any heat problems. We have had so many problems with bad power being connected to our panels and/or high heat. We began installing UPS units, and air coolers, and all the problems went away! (When our panels went out, we had no control on where or how they were installed and connected.) (We used Phoenix Contact DIN-rail-mount UPS and battery units.)

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