Three Tier Applications using the PI Historian, Microsoft Transaction Server (MTS), Internet Information Server (IIS), ActiveX Data Objects (AD0) and ActiveX Controls.

Building DNA Applications Using PI zMicrosoft Windows Distributed InterNet Applications (DNA) Architecture can enable clients to interact with PI using a Web Browser. zN-tier PI Historian applications can be developed with Visual Basic, the PI API and COM objects building data active components managed by Microsoft Transaction Server (MTS). zMiddle tier applications can send data and receive data using ADO 2.0. Using the PI API, the Historian data can be sent to ADO records sets and then passed to a requesting Client Browser using Active Server Pages and WebClass objects. zApplications can be developed using Microsoft Visual Basic 6.0 and Interdev.

VB Demonstration zWill Demonstrate the development of PI Class objects which interact with PI from n-tier application servers. zWill Demonstrate Web Based Client retrieving PI Server data as ADO Recordset using Active Server Pages. zWill demonstrate the Utilization of Custom ActiveX Controls. zWill demonstrate the IIS vb Application. Build Webclasses to talk to PI and or SQL Server.

MTS will manage n-tier Data Access Components using ADO 2.0 and the PI API zUsing MTS enables the Visual Basic PI Programmer to focus on application functionality. zThe key to integrating PI API with n-tier applications is the use of ADO 2.0! zADO 2.0 enables a programmer the ability to programmatically instantiate a new recordset using the ADO Append Method.

ADO Append Method zRetrieve data from a PI Server using the PI API zThe Append method of ADO 2.0 enables returned PI Data arrays to be converted to n-tier recordsets using MST and Active Server Pages. zAutomated COM Objects using the PI API communicating with PI Servers utilized ADO methods to interact with OLE DB Databases.

Active Server Pages Call ActiveX Components running within IIS / MTS zData access component classes are developed as an ActiveX dynamic-link library (DLL) and deployed in the Microsoft Transaction Server (MTS) environment running on Windows NT Server. zVB 6 Enables the programmer to build reusable COM components available which can be utilized within n-tier server architecture. zReusable objects can include ActiveX Controls custom built to enable reusable client browser applications. zReusable Class Objects able to communication with PI via the PI API zReusable Class Objects able to communication with OLE DB datasources such as SLQ Server 7

Retrieve PI Time as single variant Public Function DisplayPITime() As Variant Dim apistat As Long Dim sCurtime As String ' Add this first pitm_parsetime to derive the current value ' This will be used later as a relative time in case 'the user enters -1d (insted of *-1d) sCurtime = "*" apistat = pitm_parsetime(sCurtime, 0, iRelTime) DisplayPITime = iRelTime End Function

Retrieve PI Array as ADO Record Set With rs ' Place the trimmed strings into the Collection -.Fields.Append "PITime", adBSTR, 12.Fields.Append "PITagVal", adBSTR, 19.Open For i = 0 To (iNumVals - 1).AddNew !pitime = sTimesArray(i) !PITagVal = sValsArray(i) Next i End With

PI Time Web Page ActiveX DLL to demonstrate three tier PI Applications run from MTS

IIS Visual Basic Applications can be built to Interact with the PI Historian and Other Data Sources zDevelop and Debug PI API WEB Applications in the standard VB IDE Environment zApplication runs on IIS Machine. zPI Reports and Data Entry zConnection to other data sources zEasy to maintain Web code within SourceSafe.

IIS Vb Applications running under within IIS zCan use the PI API. zCan use ADO 2.0. zUtilized ActiveX Controls. zSend HTML and script to the client browser. zEnables the development of reusable components.