How can read data from Kepware server - plc

Question

I would like to development a client app to read data from machine PLC. On this machine there is a bridge pc that have the Kepware server installed, so if I run kepware client demo toolkit I can read the value of machine. So I would like to development a client for read data from this machine.
I have find this program online but I have a problem with library when I try to run it
http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&objId=25229521&lang=en&siteid=cseus&aktprim=0&objaction=csview&extranet=standard&viewreg=WW
I see the comunication is on OPC Protocol (OLE for Process Control).
Can we help me?

Answer 1

Download and install QuickOPC 5.23(.NET Framework 3.5 or 4.0) or QuickOPC 5.31(.NET Framework 4.5) from http://opclabs.com/products/quickopc/downloads
Create a VB.NET project in VisualStudio.
Add the reference, OpcLabs.EasyOpcClassic.dll to the project.
Use the following code to read data from Kepware server using VB.NET
Imports OpcLabs.EasyOpc
Imports OpcLabs.EasyOpc.DataAccess
Public Class Demand
Private Sub frm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ReadPLCvalue()
End Sub
Private Sub ReadPLCvalue()
Dim objClient As New EasyDAClient
Dim sValue As Object
Try
sValue = objClient.ReadItemValue(KepwareServerMachineName, KepwareServerID, PLCTagName)
Catch ex As OpcException
End Try
StoreToDB(sValue)
End Sub
Private Sub StoreToDB(ByVal source As Object)
'Database operations to store the value.
End Sub
End Class