gOPCUAConnector.gReadOneItem Method

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Description

Reads value of a single  OPC Node from OPC Server synchronously.

This synchronous operation may freeze your application until the end of operation.

 

VB syntax

gOPCUAConnector.gReadOneItem(ByRef itemToRead As gOPCUAReadWriteObject)

 

C# syntax

gOPCUAConnector.gReadOneItem(ref gOPCUAReadWriteObject itemToRead)

 

Parameters

ItemToRead

ReadWriteObject that holds NodeID you want to read.

 

Return Type

gOPCUAStatusCode

 

C# code example

  try

            {

                //Step1: Create a read-write object and assign NodeID

                GelecekCommon.gOPCUAReadWriteObject read_write_obj = new GelecekCommon.gOPCUAReadWriteObject();

                read_write_obj.NodeID = txtNodeID1.Text;

 

                //Step2: Run gReadOneItem method           

                GelecekCommon.gOPCUAStatusCode function_result = gOPCUAConnector1.gReadOneItem(ref read_write_obj);

 

                //Step3: Check function result and item status code and get read value.

                //For a successfull read, function result should be "Good" , status code sould be "Good"

 

                txtFunctionResult.Text = function_result.ToString();

                txtStatusCode1.Text = read_write_obj.StatusCode.ToString();

 

 

                if (function_result == GelecekCommon.gOPCUAStatusCode.Good && read_write_obj.StatusCode == GelecekCommon.gOPCUAStatusCode.Good)

                {

                    //Show value on TextBox

                    //Be careful, Value should be able to convert to string..

                    txtValue1.Text = read_write_obj.Value.ToString();

 

 

                }

            }

            catch (Exception ex)

            {

 

                MessageBox.Show(ex.Message);

            }