Getting the checksum from a CLX5000

[rootboy]

Anyone know how to get the program checksum from a Logix 5000?

Thanks!

 

[jdbrandt]

Anyone know how to get the program checksum from a Logix 5000?

Thanks!

An interesting question.

Regardless of the answer (which I assume will be somewhere between "maybe" and 'no'), the deeper question is WHY would you want to know this?

If it is to be used to detect or report possible tampering with the program image (i.e. logic) there are built-in tools for securing the 5k which would be more suitable.

 

[dcooper33]

Rootboy,
I'm speaking from my sometimes faulty memory here, but I do believe the checksum is a GSV accessible object under the "controller" class.

 

[TConnolly]

You can access the controller's change log.

See technote 55291 in the AB knowledgebase for a sample program.

 

[rootboy]

Thanks guys!

I'm not concerned with tampering, but our upload/download/compare software isn't good about letting us know when a program was changed. I would like to know when it is changed so that we can use that information to find out why it was changed.

 

[dcooper33]

Thanks guys!

I'm not concerned with tampering, but our upload/download/compare software isn't good about letting us know when a program was changed. I would like to know when it is changed so that we can use that information to find out why it was changed.

AssetCentre, if you've got the bank, is great for this. You automatically get a new revision created with timestamp when a edited file is checked back into the library. All user activity is automatically logged on the server, and can show exact neutral text of rung edits, tag values changed, controller properties changed, etc. This info is sortable by asset and user so tracking is very easy.

There's also a cool disaster recovery feature that can do scheduled backup of running plc programs and compare of archive files versus running programs for unauthorized changes.

 

[rootboy]

AssetCentre, if you've got the bank, is great for this. You automatically get a new revision created with timestamp when a edited file is checked back into the library. All user activity is automatically logged on the server, and can show exact neutral text of rung edits, tag values changed, controller properties changed, etc. This info is sortable by asset and user so tracking is very easy.

There's also a cool disaster recovery feature that can do scheduled backup of running plc programs and compare of archive files versus running programs for unauthorized changes.

Very nice! I'll check it out. Thanks!

 

[rootboy]

@bmacattack33

It doesn't look like it. Just for a mismatched checksum with the eprom ("nonvolatile memory") image. Nothing to check the main program.

In a PLC5, you can get it from S:57, but not the Logix???

This is how Ladders triggered a upload/download/compare on the old GE Series Sixes. Not only did it not waste resources trying to figure out which PLC had been changed, but it also gave us a time stamp of when it happened so we could ask the Maintenance crew that was on at that time what was worked on (although Ladders did a great job of presenting the differences side-by-side, so it was rarely necessary to do this).

 

[Operaghost]

Using the GSV:

The Controller AuditValue is a random number that changes with each modification. Yeah, yeah don't get started on "random" number generators.

The Controller ControllerLogExecutionModificationCount counts each change made to the logic or Task/Program properties.

It does not count changes to data or anything to do with creating or deleting tags.

TConnolly's suggestion can give you more detail on what changed. Rather than just a count or "checksum".

OG

 

[rootboy]

Ack! I skipped right over that! Thanks TC for the appnote, & OG for pointing out the obvious to me.

And yes, I don't necessarily need a checksum. A random number will do nicely.

Ahh, our controllers are nearly all v16's. The sample won't work for them.


Thanks again!