1756-L62S PLC Faulting when generating safety signature

Kalagaraz

Member
Join Date
Dec 2011
Location
Kentucky
Posts
24
So when going through creating logs of all our safety signatures for tracking purposes. I found one PLC without a safety signature. This one is also kind of setup weird where the Standard PLC logic, and Safety PLC logic are in two completely seperate PLC files.

I figured no problem, and tried to generate a safety signature, and soon as it got done uploading the signature the PLC faulted and completely lost the PLC program in the PLC. So I redownloaded the program and immediately same thing, PLC faults and loses program. So in the offline file, I deleted the signature and redownloaded and all good. Tried to generate signature again and boom PLC faults and loses program.

Anyone got any idea why this is? I assume it has something to do with the standard PLC logic and safety PLC logic being in seperate files...It's only losing the safety program. I can actually still go online with the standard program.

Thanks.
 
Just to add more detail:

I thought they did some funky magic at first and made the standard and safety PLC logic seperate files, but that is not the case. I just noticed there is acctually a 3rd PLC card, a standard 1756-L73 in slot 16. Then there is the 1756-L62S and 1756-LSP in the first two slots. I have no clue why they did it this way...

Thanks.
 
Not sure why you should see it fault but check for pending edits, or forces in the program. Is the 'Safety Task OK' LED lit before you try?

Losing the program sounds like the safety controller encountered a non-recoverable fault. It's possible there is a hardware issue.
 
Not sure why you should see it fault but check for pending edits, or forces in the program. Is the 'Safety Task OK' LED lit before you try?

Losing the program sounds like the safety controller encountered a non-recoverable fault. It's possible there is a hardware issue.

Yeah it's giving a non-recoverable fault when generating or downloading with a safety signature. Without the signature everything is good, production line is running right now.

We got techconnect support, so going to try giving rockwell a call in the morning and see what they say. I thought about changing out processor, but thought that would be weird for it to be a hardware fault and the only problem it causes is with safety signature.
 
Outcome?

Did you get it to work or did you end up replacing it altogether?

I have a similar case with an L73 V24.012 that craps out almost instantly after making a safety signature, but only if it has 3 programs in the safety task, normally reports a WatchDog fault even though the subroutine it points to it's empty.
 
I missed this one during my sabbatical...

A tip for any TechConnect subscribers out there...

Try to learn to use the tools you have payed for...

118821 - GuardLogix or CompactGuard : Fault Type 14 Code 01 – Task Watchdog expired, Type 14 Code 07 – Safety Task is inoperable, Type 14 Code 09 – Safety Partner controller fault
Access Level: TechConnect

I found that one a most interesting and amusing read. But, that's not to say that it is definitely the issue here for either victims.

P.s. Gerr0, the above advice was not directed specifically at you. You may or may not have a TechConnect contract. If you do not, then do let us know and we can, I'm sure, "advise" you as to what might be the problem here.

In other words, that is not a cue, as has happened in the past, for a good intentioned member to blatantly copy the contents of a locked TechConnect article into the public domain.

Regards,
George
 
Thanks Geospark!

I started by looking at the help included with logix designer, although I have access to a TechConnect account, it's always bothered me that this stuff is "sold separately"... specially when in a remote plant with spotty and slow internet access :angr:

I'll try this out tomorrow if I can, thanks again.
 
In other words, that is not a cue, as has happened in the past, for a good intentioned member to blatantly copy the contents of a locked TechConnect article into the public domain.

This is what I hate about automation vendors in the 21st century.

Sure... You purchased our incredibly expensive hardware for your automation project, and we do appreciate that. You also purchased the incredibly expensive software whose sole purpose and capability is to make the incredibly expensive hardware that you purchased functional.

Still, if you want us to share information about the bugs that other end users have discovered in our hardware and software products and how to work around them, your going to have to pay us again.
 

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