How to read an OPC item value in Excel
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 "Classic" Library" (in versions up to 5.41, "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.