View source for How to read an OPC item value in Excel

[[Category:COM]] [[Category:Example]] [[Category:Excel]] [[Category:How to]] [[Category:OPC DA]] [[Category:VBA]]
{{Warning|Effective from QuickOPC 2017.1, the method described here is obsolete for most purposes. It is recommended that you use the Excel Real Time Data (RTD Server in Excel Connector) instead.}}
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:
 [[File:howtoreadanopcitemvalueinexcel-1.png|center]]

Step 2. Select Tools -> References, check the box next to "OPC Labs EasyOPC "Classic" Library" (in versions up to 5.41, "OPC Labs EasyOPC Type Library"), and press OK:
 [[File:howtoreadanopcitemvalueinexcel-2.png|center]]

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:
 [[File:howtoreadanopcitemvalueinexcel-3.png|center]]

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

    <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>
        <span style='color:#696969; '>' Create EasyOPC-DA component</span>
        <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
  
        <span style='color:#696969; '>' Read item value and display it</span>
        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>
    <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.

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:
 [[File:howtoreadanopcitemvalueinexcel-4.png|center]]



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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.

== See Also ==

[[How to read an OPC-UA node value in Excel]]