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Please use our Code Center to obtain source-code and example projects/solutions:
http://codecenter.softwaretoolbox.com
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  Reading Array Tags using the OPC Web Client ActiveX Controls
The following example shows you how you can create a scripted-application that runs from the Web Server.
This example uses the following development languages: ASP, ASP.NET and PHP..
Objective
The web-page we will create will simply display the values of a Tag that is an array
This example assumes that you have the Software Toolbox TOPServer installed,
and a modified version of the default project "simdemo.opf" which can be downloaded here.
Source code
In order for our web-page to display anything, we need to tell the server to fetch
the Tag value from the OPC Server and then to display it in the page.
 ASP
First, you need to add the following line at the top of the page:
<%@ Language="vbscript" %>
<html>
<head>
<title>OPC Web Client Example, Single Array-Tag Read from the Web Server</title>
</head>
<body>
<p>The Tag values are: </p>
<%
'define an opc web client
Set opcWebClient = Server.CreateObject("OPCLabs.EasyDA3.0")
'define a variable to receive the tag value and then read the tag
Set valueTimeQuality = opcWebClient.ReadItem("", "SWToolbox.TOPServer", _
& "Channel_1.Device_1.TagArray_1")
'now check the status of the read
If Err.Number = 0 Then
'ok, the read was a success, but have we read an Array Tag?
If IsArray(valueTimeQuality) Then
'
'yes, this value is an array, good, proceed by iterating thru collection
'
Dim theTag
For Each theTag In valueTimeQuality.Value
Response.Write theTag & "<br>"
Next
'
Else
'this is not an array, so just display the value
Response.Write valueTimeQuality.Value
End If
Else
'error occurred doing the read
Response.Write "<font color=red>Error: " & Err.Number & ", " _
& Err.Description & "</font>"
End If
Set valueTimeQuality = Nothing
Set opcWebClient = Nothing
%>
</body>
</html>
Save your page with a .ASP extension onto your web-server. Now launch your web-browser and connect to your web-page from your web-server. You should see the
values of the tag in the web-page.
ASP.NET
This example requires the TOPServer OPC Server along with the modified "simdemo.opf" project opened so as to be able to utilize a Tag of type Array.
'Put user code to initialize the page here
Try
'create an opc web client
Dim objOWC As New OPCLabs.EasyOPCDANet.EasyDACOM
'create a vtq object and then read the tag
Dim objVTQ As
OPCLabs.EasyOPCDANet.IVTQNet = objOWC.ReadItem( _
"", _
"SWToolbox.TOPServer", _
"Channel_1.Device_1.TagArray_1
")
'were there any errors?
If Err.Number = 0 Then
'is the value we read an Array?
If IsArray(objVTQ.Value) Then
'we have an array, so lets iterate thru the collection
For Each value As Object In objVTQ.Value
Response.Write(value.ToString & "<br>")
Next
Else
'this is not an array but a single value, so display it
Response.Write("Tag not an array! Value=" & objVTQ.Value)
End If
Else
'an error occurred
Response.Write("Error reading tag: " & Err.Number)
End If
Catch ex As Exception
Response.Write("Error: " & ex.Message)
End Try
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