How to read an OPC item value in Excel: Difference between revisions

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(Created page with "This is the simplest Excel VBA example. It reads an OPC item value and stores it in a cell of a worksheet. Step 1: Create a new Excel worksheet, and select Developer -> Visua...")
 
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Step 4. Enter the code for the handler as follows:
Step 4. Enter the code for the handler as follows:


     Private Sub Workbook_Open()
     <span style='color:#800000; font-weight:bold; '>Private</span> <span style='color:#800000; font-weight:bold; '>Sub</span> Workbook_Open<span style='color:#808030; '>(</span><span style='color:#808030; '>)</span>
         ' Create EasyOPC-DA component
         <span style='color:#696969; '>' Create EasyOPC-DA component</span>
         Dim EasyDAClient As New EasyDAClient
         <span style='color:#800000; font-weight:bold; '>Dim</span> EasyDAClient <span style='color:#800000; font-weight:bold; '>As</span> <span style='color:#800000; font-weight:bold; '>New</span> EasyDAClient
 
         ' Read item value and display it
         <span style='color:#696969; '>' Read item value and display it</span>
         Range("A1").Value = EasyDAClient.ReadItemValue("", "OPCLabs.KitServer.2", "Demo.Single")
         Range<span style='color:#808030; '>(</span><span style='color:#0000e6; '>"A1"</span><span style='color:#808030; '>)</span><span style='color:#808030; '>.</span>Value <span style='color:#808030; '>=</span> EasyDAClient<span style='color:#008c00; '>.</span>ReadItemValue<span style='color:#808030; '>(</span><span style='color:#0000e6; '>""</span><span style='color:#808030; '>,</span> <span style='color:#0000e6; '>"OPCLabs.KitServer.2"</span><span style='color:#808030; '>,</span> <span style='color:#0000e6; '>"Demo.Single"</span><span style='color:#808030; '>)</span>
     End Sub
     <span style='color:#800000; font-weight:bold; '>End</span> <span style='color:#800000; font-weight:bold; '>Sub</span>


As you can guess from the code, the event handler reads a value of an OPC Item (Demo.Single) and stores it into cell A1 of the worksheet.
As you can guess from the code, the event handler reads a value of an OPC Item (Demo.Single) and stores it into cell A1 of the worksheet.

Revision as of 15:15, 31 July 2016

This is the simplest Excel VBA example. It reads an OPC item value and stores it in a cell of a worksheet.

Step 1: Create a new Excel worksheet, and select Developer -> Visual Basic from the ribbon:


Step 2. Select Tools -> References, check the box next to "OPC Labs EasyOPC Type Library", and press OK:


Step 3. Select This Workbook in the project tree, and then add a handler for opening the workbook by selecting Workbook and Open from the drop-downs on the top of he code window:


Step 4. Enter the code for the handler as follows:

   Private Sub Workbook_Open()
       ' Create EasyOPC-DA component
       Dim EasyDAClient As New EasyDAClient
 
       ' Read item value and display it
       Range("A1").Value = EasyDAClient.ReadItemValue("", "OPCLabs.KitServer.2", "Demo.Single")
   End Sub

As you can guess from the code, the event handler reads a value of an OPC Item (Demo.Single) and stores it into cell A1 of the worksheet.

Step 5. Save the file as "Excel Macro-Enabled Worksheet", close Excel, and then open the file again. The worksheet will read the OPC item and put it into cell A1, so you will see something like this:



This concept can obviously be enhanced in many different ways. Specifically, you may want to tie the OPC actions to different events, such as pressing a button on the sheet, or a periodic timer. This example project is included with the product. Please use the example from the product itself for the most up-to-date code of the example.