RSSInterested in linking to "OPC for process historian data optimization"?
You may use the Headline, Deck, Byline and URL of this article on your Web site. To link to this article, select and copy the HTML code below and paste it on your own Web site.
OPC for process historian data optimization
OPC not only provides a standardized mechanism for collection of real time process data, it also enables multi-vendor historical analysis solutions that help maximize return on process history investments.
08/25/2005
To cast your vote, log in or become a member. This quick, one-time registration gives you access to members-only site benefits.
2 votes
Page 2 of 2
OPC HDA is a mature specification that has widespread use today. Every major brand of process historian has OPC HDA connectivity available today. If the vendor of the historian does not provide OPC HDA connectivity, third party vendors can provide standardized access to the process historian. Many applications exist that leverage the OPC HDA specification. OPC HDA enabled applications that do process optimization based upon historical data calculations can easily integrate with any existing OPC HDA enabled process historian.
Several vendors provide OPC HDA enabled trending packages as well. OPC HDA is indeed a standard that has wide adoption.
Although most organizations only have a single enterprise process historian, many organizations, either through asset acquisition or multi-site integration, are faced with multiple enterprise process historians. Before OPC HDA, an organization faced with multiple vendor historians were forced to make a choice between two vendors’ historians. Integration costs, the costs associated with data migration services, and the costs of training of personnel who were using the about to be displaced historian combine to make this a very expensive choice. OPC HDA enables multi-vendor historians to provide a distributed architecture that is, not only cost effective to implement, but leverages existing multi-vendor history assets. OPC HDA enabled products exist that enable data stored in a historian developed by vendor X to be transferred or shared with a historian from vendor Y. OPC HDA has effectively turned a problem of the past into an advantage for the future!
OPC DA and OPC HDA history solution
(Click the Download Now button below to see a .pdf version of this graphic.)
One can easily see how OPC DA has provided a process historian with a standardized mechanism for real-time data collection. OPC HDA can be leveraged to provide a standardized interface to the stored process history data. The combination provides a very useful combination for solving multi-vendor, best of breed architectures. OPC DA and OPC HDA can also be combined to solve the store and forward problem. Store and forward is a concept that is used by process historians to enable remote data collection for a process historian. During a connectivity break between the collector and the process historian, data is buffered on the remote location and forwarded to the process historian when the collector-historian link is restored.
Distrubted OPC history architecture
(Click the Download Now button below to see a .pdf version of this graphic.)
The problem with the proprietary collector problem is the lack of access to the buffered history data. Although data is constantly buffered at the remote location, the collectors provided by the historian vendors do not typically provide historian tool access to this buffer. Using an OPC HDA desktop class historian, data can not only be collected remotely using the OPC DA specification, the data can be transferred to the enterprise process historian using OPC HDA. This can either be done on a scheduled basis, or in the event of communication failure between the remote site and the enterprise process historian. Both of these solutions provide full time access to the historical data at the remote site, even if communication to the enterprise historian is not possible. Solutions like these mentioned leverage a powerful combination of OPC DA and OPC HDA connectivity.
Conclusion
Off-line process history analysis using a process historian and a set of analysis tools has indeed proven to reduce costs and provide vital production tracking. OPC has provided a standardized solution to real-time data collection. Real time data sources are accessed using the OPC standard interface. Historian vendors no longer need to focus on data collection, or data visualization and presentation due to the widely adopted OPC HDA specification. Using OPC, organizations are free to choose, not only what vendor supplies the data analysis and presentation tools, they are also free to choose the vendor or vendors that supply the process historians for the organization. OPC HDA enables a true distributed historian solution.
| About the Author |
Click the Download Now button below to see a .pdf version of the graphics referenced in this article.
Page 2 of 2
To cast your vote, log in or become a member. This quick, one-time registration gives you access to members-only site benefits.
2 votes
ControlGlobal.com is exclusively dedicated to the global process automation market. We report on developing industry trends, illustrate successful industry applications, and update the basic skills and knowledge base that provide the profession's foundation.
