[foxboro] OPC Tag Quality

From: "Puckett, Michael K" <michael.k.puckett@xxxxxxxxxxxxxx>
To: "foxboro@xxxxxxxxxxxxx" <foxboro@xxxxxxxxxxxxx>
Date: Wed, 8 Aug 2012 06:30:37 -0600
We are experiencing issues with our Aim* OPC HDA and DA servers and hope 
someone else has seen this and knows of a solution:
Here is our setup on two identical DCS's:
I/A 7.1
Aim* OPC DA installed on AW P80
Aim* OPC HDA installed on Windows Server 2003 (This machine also serves as our 
remote historian)
We are collecting about 950 tags on the OPC HDA as read only from the historian.
We have about 20 points that are read/write on the DA

Before this we had Matrikon OPC for Foxboro installed on a independent Windows 
Server 2003 Computer on the secondary network.  It pulled data through an AW on 
our I/A 7.1 network.

We changed to Aim* OPC HDA to limit the loading on CPs.

If we ever have a break in communications and need to restart the OPC server 
then we get about 20 to 40 tags that  the quality is "bad, non-specific".  The 
rest of the tags are good.  Restarting the OPC server does not fix the problem. 
 The same tags continue to be bad.  The only way we have found to get the tags 
to change to good is to go into the DCS and change the value of the tags.  Each 
time we have the issue it is different tags that will have the bad quality.  
The common relation to them all is that they are parameters that have remained 
constant for several days.  (Example: HOLIM & LIM on LIM blocks, Booleans on 
Calc blocks, and more).  Once we move the parameter in the DCS, it will stay at 
a good quality as long as the OPC server is running.  I thought it may be the 
HDA server but if I browse the same block.parameter through the DA server, the 
quality is bad as well.

This problem also happened with the Matrikon OPC server.  From my understanding 
Matrikon used Fox API and Aim* OPC uses Aim API.

Thank you in advance for any help you can give us with this problem.


Kalam Puckett

 
 
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[foxboro] OPC Tag Quality

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