FAWEB.NET / OPC Server - VB.NET Sample

	SITEMAP PRIVACY JAPANESE

JAPAN	HOME \| Product \| Support \| Knowledge \| Download \| Sales \| Company \| Contact

You are Here : HOME > Product > OPC Server > Visual Basic .NET Sample

BACK

OPC Client Sample of Visual Basic .NET

It introduces the easy sample program using the OPC Server. The code of this sample uses OPC Automation Wrapper (OPCDAAUTO.DLL), so it is almost equal to VB6.0.

The sample program can be downloaded here.

	Sample Display
In this sample, it executes connecting to OPC Server, reading data automatically, reading data manually and writing data manually.

Sample Code

Option Explicit

Public OpcServer As IOPCServerDisp
Public OpcItemMgt As IOPCItemMgtDisp
Public OpcItem As IOPCItemDisp

Private Const ItemMax = 8
Private Const OPC_DS_CACHE = 1
Private Const OPC_DS_DEVICE = 2

Dim ClientHandles(ItemMax) As Long
Dim ServerHandles As Variant
Dim bConnect As Boolean 
Private Sub CONNECT_Click()
	On Error GoTo problem
	Dim i%
	If bConnect Then
		CONNECT.Caption = "Connect"
		Set OpcServer = Nothing
		Set OpcItemMgt = Nothing
		Set OpcItem = Nothing
		bConnect = False
		READ_Button.Enabled = False
		WRITE_Button.Enabled = False
		For i% = ItemName.lbound To ItemName.ubound
		  ItemName(i%).Enabled = True
		Next i%
		Exit Sub
	End If

Set OpcServer = CreateObject(Form1.ServerName.Text)
	If TypeName(OpcServer) = TypeName(Nothing) Then Return

Dim UpdateRate As Long
	Dim ServerHdl As Long
	UpdateRate = UpdateRateSet.Text
	Set OpcItemMgt = OpcServer.AddGroup("Group One", True,
						  UpdateRate, 22, 1, 0, ServerHdl, UpdateRate)
	If TypeName(OpcItemMgt) = TypeName(Nothing) Then Return

Dim ItemIDs(ItemMax) As String
	Dim AccessPaths(ItemMax) As String
	Dim Active(ItemMax) As Boolean
	Dim Errors As Variant
	Dim ItemObjects As Variant
	Dim DataType(ItemMax) As Variant

For i% = 0 To ItemMax - 1
		Active(i%) = True
		ClientHandles(i%) = 22 + i%
		AccessPaths(i%) = ""
		ItemIDs(i%) = Form1.ItemName(i%).Text
		DataType(i%) = 2
	Next i%
	OpcItemMgt.AddItems ItemMax, ItemIDs, Active,	
				ClientHandles, ServerHandles, Errors,	
				ItemObjects, AccessPaths, DataType

Set OpcItem = ItemObjects(0)
	bConnect = True
	CONNECT.Caption = "DisConnect"
	READ_Button.Enabled = True
	WRITE_Button.Enabled = True
	For i% = ItemName.lbound To ItemName.ubound
		ItemName(i%).Enabled = False
	Next i%
	Exit Sub

problem:
	MsgBox "Error connecting"
	For i% = 0 To ItemMax - 1
		Form1.Value(i%) = "Error"
	Next i%
End Sub

Private Sub Form_Load()
	Dim i%
	For i% = 0 To ItemMax - 1
		Form1.ItemName(i%).Text = "UC24.D" + Format$(i%)
	Next i%
End Sub

Private Sub READ_Button_Click()
	Dim ReadValue As Variant
	Dim pQuality As Variant
	Dim pTimestamp As Variant
	Dim Errors As Variant
	Dim i%
	Dim io As IOPCSyncIODisp

Set io = OpcItemMgt
	io.OPCRead OPC_DS_CACHE, ItemMax, ServerHandles,	
						ReadValue, pQuality, pTimestamp, Errors
	For i% = 0 To ItemMax - 1
		Form1.Value(i%) = ReadValue(i%)
		pTimestamp(i%) = DateAdd("h", 9, pTimestamp(i%))
		Form1.Time(i%) = pTimestamp(i%)
		Form1.Quality(i%) = pQuality(i%)
	Next i%
End Sub

Private Sub WRITE_Button_Click()
	Dim WriteValue(ItemMax) As Variant
	Dim io As IOPCSyncIODisp
	Dim Errors As Variant
	Dim i%

Set io = OpcItemMgt
	For i% = 0 To ItemMax - 1
		WriteValue(i%) = Form1.Value(i%)
	Next i%
	io.OPCWrite ItemMax, ServerHandles, WriteValue, Errors
End Sub

BACK	Copyright © 1998-2006 TAKEBISHI Corporation All rights reserved.

TAKEBISHI Corporation
29 Mamedacho Nishikyogoku Ukyoku Kyoto 615-8501, JAPAN
TEL: +81-75-325-2171 / FAX: +81-75-325-2273 fa-support@takebishi.co.jp