Analog Out of Range

[ewoenne]

Hi,

I can't find a specific explanation of this anywhere.

What is the best way to approach analog out of range alarms? Set up a WinCC OA value range on the dp & then create another alarm dp which is triggered by the _out_range attribute of the analog? Is there a way to do this all within the analog dp?

[ozangor]

I think it's better to add an alert handler to your analog dpe, and set the range limits to generate alarms.

[ewoenne]

Thanks for your reply. I did try that & got slightly strange results:

I have an alarm set up with the folllowing

- normal range
- hi range (low priority)
- hihi range (medium priority)
- OOR, above hihi range (low priority)

When the value is out of range, the alarm displays in the alarms list but the para still shows the text and colour of the hihi alarm.

[ozangor]

I tried it with a simple float datapoint. It seems to work fine. Can you please post screenshots of your _alert_hdl and _pv_range configs?

In _pv_range do you have the checkbox ticked before "Ignore values otside of value range"? This will prevent the datapoint element to have values out of range. However, in this case you should not be seeing the alarm in the alarm list.

And check your _alert_class configs for the used alarm classes. You may need to set the acknowledgment type to something that would work for you.

Do you have _default config defined for your datapoint?

[ewoenne]

Hi Ozan,

I don't have the 'Ignore values' checkbox ticked, there is no _default config configured and the alarm class ack type is 'CAME or WENT must be acknowledged'

Config screenshots attached

[ozangor]

I can't see any screenshots, Ellen :/

Oh, I see them now.

I could not see a problem in the configuration here. Which version/patch of WCCOA do you have?

[ewoenne]

We're using v3.15 patch 6

[ozangor]

I tested it with the same version.
How does it behave if you change the upper-value limit to a larger value? Does your alert color update in that case?

[ewoenne]

Sorry, which value did you want me to test?

I think the problem is with the alarm classes as the OOR is a lower priority than the HiHi:

OOR - low class priority 20
HiHi - medium class priority 40
Hi - low class priority 20

If I test it with all ranges as the same alarm class I get the correct text (OOR when the value is > 100)

[Gertjan van Schijndel]

Ellen Woenne wrote:

I think the problem is with the alarm classes as the OOR is a lower priority than the HiHi:

That is the correct conclusion. The documentation contains this statement regarding the continuous alert handling: The alert classes have to be assigned according to increasing priority.
Also 120.0 is bigger than 50.0, so the highest priority is used.

The discrete alert handling must not be used with float element types, otherwise you could have used this and specified the value ranges and/or the value out of range state bit.