bespoken (Customer) asked a question.

November 7, 2020 at 2:12 AM
P1000 will randomly turn off outputs

I am running a P1000, 2 input and 3 output modules. A few times a day the PLC will shut the outputs off and not respond to button inputs. I have to toggle the run switch and it comes back online and works. I went through and checked my wires, no shorts.

 

I find that this happens when the system is in idle mode - I have 10 output coils that are on and all will shut off. I would be glad to post the program that I am running if that would help. But it seems like there is some type of hardware issue causing the problem.

 

Any ideas?

 

Thanks,

 

Scott

 

  • 16 answers
  • 444 views

    • bespoken (Customer)

      I am using the P1 power supply with 5 modules - under the limit for power. I have a 2.1 A power supply for the inputs and outputs. I checked the max output with all possible outputs energized and the load was 1.6 A.

       

      I now seem to recall that the unit did lock up a few times when I did not have any wiring going to the inputs or outputs - just using the input simulator. I am going to try using the input simulator to see if that can reproduce the issue (it is not connected now). This is leading me to believe that I have an issue with hardware.

       

      Scott

       

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  • z28z34man (Customer)

    Are you using indirect addressing at all? I don't remember if the productivity series dose it but a AB PLC 5​ will lock up if you indirect address to a address that doesn't exist in memory.

    • bespoken (Customer)

      All addresses are in memory, so I do not think that is the issue. I had the issue pop up with a very simple program. Using the input simulator and a couple of outputs.

       

  • Todd Dice (Customer)

    I would check the firmware of the CPU, and confirm it's the latest version.

    • bespoken (Customer)

      HI Todd - it is the current version. I am going to test it without any wires hooked up and see if the input simulator can cause the crash.

  • bespoken (Customer)

    I did another test - with nothing hooked up to the inputs or outputs, and it crashed after sitting idle - after turning on the outputs using the input simulator. Took about 1 min and 30 seconds and all the input lights shut off.

     

    Attached are images of the program that I am running when it crashed.Screenshot (12)Screenshot (13)

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    • Todd Dice (Customer)

      I note in rung 4.1 and 4.2 the outputs are the very same. Now, in ladder last referenced tag wins, but the fact you have it repeat in the same rung "may" be the problem. IF you wish to reference the same output tag, you should use the OR, aka Or Out. Otherwise, I see no reason for the CPU crashing.

      • bespoken (Customer)

        Screenshot (10)Thanks Todd - I wrote a quick program and duplicated an output, not an intentional error.

         

        I then configured the PLC with just one output module and the input simulator, and it still errored out. Attached is the program.

         

        I also did a firmware update (same version as installed) to see if there was an issue with the firmware.

         

        I will be calling up customer support on Monday. Looks like the PLC is having some issues.

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  • SS757 (Customer)

    Hi Scott,

     

    I am experiencing a very similar issue on a P1-540 with FW 1.2.9.27. I have a 1 rung program that will crash within 10 seconds with no I/O wired. If I downgrade the firmware to FW 1.2.8.30, it runs fine. Can you try installing 1.2.8.30 if you have it?

     

    As a side note, I have a 2nd P1-540 that runs the same program perfectly fine with both firmwares.

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