Roger Palmen

Direction to take for mass balance check

Discussion created by Roger Palmen on Jan 7, 2013
Latest reply on Jan 8, 2013 by MIPAC

Dear all,

 

I'm still a bit unsure about how to utilize AF properly, based on 1) the currently available technology and 2) where the technology will move in the (near) future.

 

But let's start with my problem description:

 

I have a fairly simple process where a number of flows are measured. Some measurements for product supply, and some measurements for product usage. The simple question to answer: Calculate a mass balance to be a rolling 24h with a refresh every 4 to 6 hours. Errors greater than +/-10% to cause alarm.

 

My ideas for a solution:

 

1) Use an AF Element for the process, and a Formula DR to perform the mass balance calculation. Next use Notifications to clock schedule the alarm if the imbalance is too large.

 

2) Use an AF Model and AF Analysis. Use ACE to create an Analysis case every x hours, and persist that to a PI tag, which is referenced in an AF Element attribute.  Through a PI Notification send an alarm

 

3) Use Event Frames to perform the calculation. Use ACE? (or Event Frames interface) to create an Event Frame based on a template. Event Frame performs the Imbalance calculation on the referenced AF Element. Not sure how to get a notification triggered when the EventFrame has been created.

 

Scoring:

 

1) is a straightforward solution that will work now and in future, and i like it for it's simplicity. But somehow i get the feeling i'm missing out on some of the goodies that AF provides in terms of the AF Models and Analysis.

 

2) It's somewhat a mix between old (ACE) and new AF Analysis. I'm very unsure if this will work and if it will add any benefit over the other solutions. It's a bit of a spaghetti solution... Also unsure about the future-proof-ness of this solution regarding AF Analysis. I'm not the only one with this uncertanity as Joel's post has somewhat the same concerns: http://vcampus.osisoft.com/discussion_hall/development_with_osisoft_sdks/f/28/t/3698.aspx

 

3) It might be an approach, but i'm still missing out on how to create the Notification.

 

 

 

Your thoughts are very welcome!

 

 

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