Analog Alarms

Hi Nuno ,

The change that caused this behavior was documented in the Update 25 readme:

"Trends 1633791 - [Trend]RangeCheck would not plot values if the scale is beyond the defined range. The I/O Server will now send updates to trend and alarm servers for Uncertain_Eng_Unit_Exceed values for further processing based on the value set for the parameter [Trend]RangeCheck."

What was previously happening, is that values that were outside the Engineering range, where not being sent to the Alarm/Trend Server with drivers that utilise the Driver Runtime Interface (OFSOPC, OPC, OPCLX, OPCUA, DNPR, BACNET, IEC61850, S7TCP, etc). This was in contrast to how polled drivers behave.

The fix was to bring DRI and non-DRI drivers into alignment. As per the readme, the I/O Server now sends values to the Alarm/Trend servers for processing now.

While this change was specifically made to address a customer issue with the trend logging values, it can also impact Alarm event triggering.

In your situation, is the #UNC an out of engineering range? It might be worth looking at your configured engineering range on the Variable tags. And also if the field device requires calibration.

If you still believe this change impacts you negatively, I recommend reaching out to AVEVA technical support and requesting further investigation.

Kind regards

Olivier

Hi Oliver,

Yes in our situation, the #UNC is out of engineering range.

The equipment in question are well calibrated, although they are broken.

Is there any parameter that allows, in this situation, to deactivate the analog alarms while these equipment are not replaced?

Best Regards

Nuno

Hi Nuno ,

Apologies for the delay. I missed your reply.

I believe the parameter [Trend]RangeCheck only applies to the Trend Server.

I recommend you reach out to AVEVA support to raise an issue request to give you the ability to enable/disable alarms being generated when out of engineering range.

Kind regards

Olivier

Hi Oliver

E add the disable alarm ability so that in those situations the analog alarm are not raised. 

Thank very much for your time.

Best Regards

Nuno

Hi Oliver

E add the disable alarm ability so that in those situations the analog alarm are not raised. 

Thank very much for your time.

Best Regards

Nuno