Controllogix SD card

[[email protected]]

Hi,

I am using a Controllogix L72 processor on a project, and I was wondering if there was a way to store the program and data onto the included SD card without taking the PLC out of run mode. From what I have read, the information is stored automatically when the PLC is powered down, or can be done from within the RsLogix5000 software in online mode, but this would lock the processor during the store.

I would like to be able to do this via a command in the PLC, so that the data could be backed up upon command from an HMI,but leave the program still running.

Does this sound possible?

Thanks for the help!

-Jim

 

[Ken Roach]

It's not possible with the current architecture of the controller, and I doubt it will ever be built into the controller.

Consider what the save-to-nonvolatile-memory needs to do: it backs up the whole User program, and the entire contents of the database. To do that "on the fly" it would have to copy the whole database to a buffer instantly, then copy the whole User program (probably locking out or canceling edits) to another buffer, then write both to nonvolatile memory.

That would require that the runtime memory of the controller be at least double its operational memory, and then there's the practical matter of whether you can copy the whole Tag Database fast enough to not cause an interruption to the user logic.

What I'd like is an easier-to-use method for programmatically copying Tags and Arrays to nonvolatile memory, then invoking a comparison or loading of those tags and arrays.

There are certainly tools for pulling data for storage outside the controller during runtime; complex ones like FTAssetCentre or simple ones like the Offline Tag Save/Restore tool.

 

[[email protected]]

Ken,

Thanks for the response. I agree with you completely, and it makes sense that it wouldn't work. I just wanted to check to veify the information for a customer and make sure I wasn't missing something.

-Jim

 

[Ken Roach]

To be complete, there are methods for writing data to the CF or SD cards programmatically during runtime, but not the whole save the logic-and-database like when you shut down the controller.

Things might change in the future, of course; I haven't dealt with the "L7x" architecture and its L1x, L2x, L36x, etc derivatives closely.

 

[[email protected]]

That's interesting, and really what I was looking for. I don't need to save the logic itself, just data. I would like to be able to, for instance, write calibration numbers to NVM by pressing a button on the HMI.

I have looked around a lot for that, and as yet I have come up empty. Can you point me towards any examples or litereature I can look at?

Thanks again,
Jim

 

[Ken Roach]

There's a Publication that describes this function, which allows you to save user data as an ASCII file on the CF card.

CompactFlash File System on Logix5000 Controllers.
http://literature.rockwellautomation.com/idc/groups/literature/documents/ap/logix-ap007_-en-p.pdf

Knowledgebase document 28539 has a good overview of the function and mentions that controllers that use SD cards (like the L7) don't require the manual integrity check logic. There are example programs in RSLogix 5000's Sample Application library.

 

[[email protected]]

Thank you very much, Ken, that was exactly what I was looking for.

 

[junior]

This document only talks about the controllogix controllers, would this be the same for compactlogix controllers like the L35E?

 

[xzen]

Rockwell Knowledgebase Access

I tried to get the Knowledgebase document 28539, as it seems to hold answers to how to save tag values to non-volatile memory. But I find Rockwell Automation Knowledge Base inaccessible and almost hostile . After finally getting my account registered, I expected to get access to the answers that I need. But then they start asking for TechConnect Support Contract, Contact record, Authorization number and blah, blah, blah, …
Is there a simpler way to get this document? Or can anyone explain the concept of Rockwell Automation Knowledge Base and the terms "TechConnect", "Support Contract", "Contact record" etc?

 

[Paullys50]

I... Or can anyone explain the concept of Rockwell Automation Knowledge Base and the terms "TechConnect", "Support Contract", "Contact record" etc?

Simply, "luxury" information requires a "luxury" price tag. If you pay for the yearly support from Rockwell you get access, if you don't pay for it you don't get it.