Rockwell GuardLogix 5580

[BiteBytesButes]

Hi...

I have what is so-called "Limit Values" placed in the Safety PLC. These values ​​were written in REAL safety tags format.
It turns out that, after the Safety function on PLC be "closed" (Safety blocked) I cannot update them via SCADA writing.
I understand why this isn't possible, it is the Safety function itself does not allow it.
Is there any way to achieve this? Be able to update these tags via SCADA?

" from Rockwell GuardLogix manual:
The safety-lock feature applies only to safety components, such as the safety task, safety programs, safety routines, safety tags, safety Add-On Instructions, safety I/O, and safety
signature."
Thank you!
3B

 

[Robobob]

You can use the Map Safety Tag function. Have your SACDA write to PLC Global tags and then Map the Global tag to the Safety tags. The data will pass from the Global tags to the Safety tags. See attached images.

 

[ASF]

You can use the Map Safety Tag function. Have your SCADA write to PLC Global tags and then Map the Global tag to the Safety tags. The data will pass from the Global tags to the Safety tags. See attached images.

You can (though you will have to unlock the safety to do this) but in almost 100% of cases you absolutely should never do this.

No matter what precautions you take, the moment you expose a safety limit to be able to be changed by non-safety code, you no longer have a safety function. Even if you place limits on the SCADA entry field, there's nothing to stop me from accidentally fat-fingering a change to the non-safety tag in Logix and accidentally setting the overtemperature cut out to 10909 degrees instead of 100 degrees.

 

[jstolaruk]

I have passed editted limits via mapping but the safety task tested the value and only used what was called out usable/valid/safe in the risk assessment.