Read ControlLogix CPU Usage % via CIP Message

[PLCPrgmr]

I would like to Read the CPU Usage % information like the Task Monitor tool provides from one ControlLogix to another via a CIP Message.

Comms
System
User Task
ASCII
Comms IO Monitor

Any ideas would be greatly appreciated!

[AlfredoQuintero]

I did not know about this put it seems some Logix controllers support class 72 "user memory object".
https://literature.rockwellautomatio...m015_-en-p.pdf

[PLCPrgmr]

Thank you! I am already polling the memory information.

[AlfredoQuintero]

That was fast. Glad to know I was able to help

[PLCPrgmr]

Well, they are doing it in the Task Monitor tool.. Here was my answer from Rockwell...

Hello Michael,

Greetings of the day, hope you are doing well.

We suggest you to please refer the following technote link for your query.
CPU utilization of a Logix controller https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/116890/track/AvP8KQrqDv8S~S4sGoIK~yI8XP8qrC75Mv8W~zj~PP~f"]

[_Derek]

PLCPrgmr,

Do you mind pasting in the text of that response by Rockwell?

I can't access your link or see it here.

Thanks,
Derek

[RedDraw]

Originally Posted by _Derek

PLCPrgmr,

Do you mind pasting in the text of that response by Rockwell?

I can't access your link or see it here.

Thanks,
Derek

It's techconnect level. If you have techconnect copy and paste just the linked text into another browser window.

[plvlce]

The actual link in the post will not work because it is malformed due to including quotation marks around it. Manually copy and paste it and it will work, although as RedDraw notes it is techconnect restricted.

PS You can drop everything after the actual id number (116890) from the link.

[_Derek]

thanks for responding, i'm not techconnect level.

[janner_10]

Why would you want to know this programmatically?

Edit: that is a genuine question btw, I'm just interested.

[_Derek]

I'm working on implementing the "Top 20 Secure PLC Coding Practices" This would help me implement Practice 19

Link to top 20 practices https://plc-security.com/

[janner_10]

Sort of **** some of our 'I know best' customers come up with, until they see the PITA tax they have to pay.

[ARandomFieldEngineer]

Originally Posted by janner_10

Sort of **** some of our 'I know best' customers come up with, until they see the PITA tax they have to pay.

Depends on the customer. For power plants and water treatment facilities, I can understand their concern.


For OP, to answer your main question, check out RA's document number 1756-rm003-en-p. That document breaks down what objects you can pull values from with the GSV/SSV instruction. You could pull those into an array for your CIP message instruction.




But from taking a look at the "top 20 secure plc practices", pulling that data isn't going to make you secure. What they're saying is that by monitoring that data, you can ensure that no extra code is added without your knowledge.


With access to your system someone could just stop the GSV instructions from looping, then the CIP message endlessly repeats that everything is fine.


You'd be better off enabling change detection and other security settings.