how to fix error s:1/13

hey i am kinda new to this whole plc stuff but i am getting s:1/13 error (major error halt). i have recently switched the plc to a very similar machine but cant figure out why this error is coming up.

What make and model of controller ? It sounds like an A-B SLC or MicroLogix.

Can you clear the fault? Is it persistent, recurrent, or intermittent ?

it is a micrologix 1500, 1764-lrp processor.
it wont let me clear it at all it pops on as soon as it is in run mode

i have recently switched the plc to a very similar machine but cant figure out why this error is coming up.

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What do you mean by "switched a PLC". Can you give us a description of the fault.
I assume that you can get online with the processor and retrieve the fault description.
Without knowing the fault description all we know is that there is a PLC fault that’s all. The more detail you provide the further we can assist.

Below is a processor fault just to give you a detail. In the project tree to go Processor status, once the Status window appears go to Errors, then you can retrieve a processor fault description. Once we know what the error description is we can get to the root cause of the problem.

the fault is s6:B8Bh with the s:1/13
it says it is a user defined fault but i dont know how to check what it was set to

If it's a user defined fault, then your program must have moved a value into S:6 in order to define it.

so how do i tell what is wrong with it? i believe the fault light on the plc is a solid red light if that makes a difference

Can you post the PLC program?. Zip it first.

I looked up the fault codes for your processor. While "B8Bh" is not within the range of suggested values for generating a user defined fault, it doesn't appear to be a valid fault code either. Perhaps the firmware in your new processor is generating a fault code that your programming software (as well as the manual that I referenced) doesn't recognize and that is why it reports a structured text message for "user defined fault"?

Have you checked for the more obvious issues, such as an I/O configuration mismatch? What kind of I/O do you have installed? Could it be a firmware incompatibility issue?

I'd try removing all of my I/O modules and then write and download a null program to see if the processor faults under those circumstances.

I have the processor from the other machine so I will try replacing the processor if that doesn't work I will try to remove the I/O and see if that works

A general principle of Allen-Bradley MicroLogix and SLC-500 controllers is that they are very vigilant about their I/O configuration.

They will always check to be sure that exactly the same I/O modules defined in the program are actually connected to the controller. Just one module being different (like a DC output instead of an AC output, or an 8-point module instead of a 16-point module) will cause an I/O related fault.

That's why "switching the processor to a very similar machine" suggests that the I/O configuration on the other machine is slightly different.

A solid red RUN indicator on the controller is a "non-recoverable major fault", which you already know. That means it can't be cleared by software or by switching modes (run -> prog -> run).

The best way to solve this problem is to carefully examine the error code and the RSLogix 500 program, paying special attention to the I/O configuration.

Different I/O modules in the second machine was the first thing that popped into my head also, Ken.

...if that doesn't work I will try to remove the I/O and see if that works.

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If removing the I/O is all you do, that won't work either. You have to always make sure that your PLC program has its Inputs and Outputs configured exactly the same as they really are physicallly. Any mismatch will always result in an error.

So I have checked all my I/O they are all correct but I was wrong about the fault light it i flashing not a solid light does that make a difference?

All of these answers are in the Users Manual.

Try the first link.

Bit Bucket, to mix some metaphors, "you can lead a horse to water, but you can't make him drink the Kool-Aid."

According to this page C-1 from the MicroLogix 1500 User Manual, a red flashing LED indicates a User Program Fault that can be reset. If the program condition (dividing by 0 is a common fault condition) causing the fault is not corrected, you can reset the PLC fault, but it will again go into fault mode as soon as the PLC is switched to RUN.