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Author: J. Singh, Konjengbam

 

Software structure and Model for Audi Project:

 

Introduction:

The Audi project is currently in the inception period. Software modeling and prototype testing is in process. The back-end database model is near about completion but refinements may need to be done. OPC/DDE interface is yet to be built if commercial bridge software is not to be procured.

 

In essence, this project is similar to the BGU project with refined software components and better software model.

 

Module requirements:

Following are the basic software modules required for the integrated deployment:

• OPC Server (non-lesswire)

In-touch or Siemens may supply the OPC servers for operation of OPC Services. These server(s) may communicate with the PLC systems for the factory data. For testing, lesswire is also equipped with one Demo OPC Server, which was developed during BGU times.

 

• OPC Interface for Web (lesswire)

This provides the interface between OPC servers and the Web applications. The purpose of this class is to provide an Active-X component in DLL form so that ASP scripts or VBA apps could launch and use OPC services via this component or interface.

 

This is an update of the BGU implementation and will be now referred to as OPCInterface. The old term had been ActiveX-OPC Client.

 

• Data Interface for MS-SQL Server (lesswire)

This Active-X component has been newly introduced in consideration of the MS-SQL database. Querying etc and other database operations/manipulations can be performed via this component/interface.

 

Earlier implementations had been in the ASP, creating ADO Recordset objects in ASP module and opening and closing database etc. An encapsulated module is being provided here, separating database operations from OPC operations.

 

 

• OPC/DDE Interface (s)

It is not yet known whether this bridge is going to be procured on a commercial basis from a vendor. This OPC/DDE Bridge is required for those DDE servers that implement data-exchange via the DDE protocol.

 

It is possible to write a custom Bridge for lesswire AG but that would require Wintech’s license for OPC toolkit.

 

• ASP Pages (lesswire)

These are the web documents running at server-side offering Web-OPC services. Data can be read or written via the OPC interface.

 

With the introduction of distributed components, the ASP coding will become thinner but cleaner and easier.

 

• MS-SQL Database as Back-End (lesswire)

For the back-end server, MS-SQL server is deployed. Databases are created and the basic OPC configurations are exported from the BGU implementations. More extended tables are created for the Audi project.

 

Components for the Audi project:

Below are the components required tentatively for deployment.

 

 

 

 

 

 

Schematic Diagram of the Software Integration and Flowchart:

Below is the software model on a tentative basis for the Audi project.