Subscribing to PLC data via code

VB Example:

The AdvancedHMI drivers support a subscription that will automatically poll data and return the values. The DataSubscriber provides a non-code method of using this service. However, there are times when it is desired or more efficient to subscribe using code. This is an example on how to do this:

   Private SubscriptionID1 As Integer
   Private Sub Button2_Click_1(sender As Object, e As EventArgs) Handles Button2.Click
       SubscriptionID1 = EthernetIPforCLXCom1.Subscribe("MyTag", 1, 500, AddressOf Subscription_DataReceived)
   End Sub

   Private Sub Subscription_DataReceived(sender As Object, e As Drivers.Common.PlcComEventArgs)
       If e.ErrorId=0 AndAlso e.Values IsNot Nothing AndAlso e.Values.Count>0 Then
           Label1.Text = e.Values(0)
       End If
   End Sub

   Private Sub MainForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing
       EthernetIPforCLXCom1.UnSubscribe(SubscriptionID1)
   End Sub

The rate at which data is polled is determined by the value of the PollRateOverride property.

Each driver is highly optimized for communications using subscriptions. All of the visual controls (e.g. Gauge) use the subscription mechanism to receive their data.

C# Example:

The Following is an example of how to programmatically set the comm drivers and create subscriptions to PLC addresses using the "DataSubscriber2" control. The "DataSubscriber2" runs on a background thread which allows for asynchronous capability when gathering tag information.

   using AdvancedHMIDrivers;
   using AdvancedHMIControls;
   using MfgControl.AdvancedHMI.Drivers;
   using System;
   using System.Collections.Generic;
   using System.ComponentModel;
   using System.Data;
   using System.Drawing;
   using System.Linq;
   using System.Text;
   using System.Threading.Tasks;
   using System.Windows.Forms;
   //
   namespace AdvancedHMICS
   {
       public partial class MainForm : Form
       {
           #region Initalize Comms & Properties
           // Always have 3 Comm Drivers (Slow, Medium, and Fast)
           // It doesn't slow down your application because this all runs on a background thread
           // and the comms drivers poll from the same datalink layer 
           EthernetIPforSLCMicroCom CommSlowDewaxer1 = new EthernetIPforSLCMicroCom();
           EthernetIPforSLCMicroCom CommMediumDewaxer1 = new EthernetIPforSLCMicroCom();
           EthernetIPforSLCMicroCom CommFastDewaxer1 = new EthernetIPforSLCMicroCom();
           //
           // The following variables set the properties of the comms above in the project
           string CommDewaxerIPAddress = "10.60.48.138";
           int CommSlow = 1000; // polling every second
           int CommMedium = 500; // polling every half second
           int CommFast = 200; // polling every 200 milliseconds
           #endregion
           //
           #region DataSubscribers
           bool initalizeSub = false;
           // Dewaxer 1 Subscribers
           DataSubscriber2 DataSlowDewaxer1 = new DataSubscriber2();
           DataSubscriber2 DataMediumDewaxer1 = new DataSubscriber2();
           DataSubscriber2 DataFastDewaxer1 = new DataSubscriber2();     
           #endregion
           //
           public MainForm()
           {
               InitializeComponent();
               //
               #region Set Comm & Subscriber Properties & Items
               if (initalizeSub == false)
               {
                   #region Set IP Addresses, Poll Rates, And Subscription Comms
                   // Dewaxer Comms
                   CommSlowDewaxer1.IPAddress = CommDewaxerIPAddress;
                   CommSlowDewaxer1.PollRateOverride = CommSlow;
                   //
                   CommMediumDewaxer1.IPAddress = CommDewaxerIPAddress;
                   CommMediumDewaxer1.PollRateOverride = CommMedium;
                   //
                   CommFastDewaxer1.IPAddress = CommDewaxerIPAddress;
                   CommFastDewaxer1.PollRateOverride = CommFast;
                   //
                   // Bind Dewaxer Data Subscribers to Comms
                   DataSlowDewaxer1.ComComponent = CommSlowDewaxer1;
                   DataMediumDewaxer1.ComComponent = CommMediumDewaxer1;
                   DataFastDewaxer1.ComComponent = CommFastDewaxer1;
                   #endregion
                   //
                   #region DataSubscribers (Continuation)
                   // NOTE: This is two different ways of adding elements programmatically
                   //
                   // Example 1    
                   // This is one way of adding individual tags to the data subscriber during creation of the project
                   // and then adding these items to the subscriber in the form
                   // NOTE: You can create these items during runtime as well (like with a button press)
                   PLCAddressItem Dewaxer1Temperature = new PLCAddressItem("N7:10", 1, "D1Temp", "Dewax 1 Temperature", 1, 1);
                   PLCAddressItem Dewaxer2Temperature = new PLCAddressItem("N7:11", 1, "D2Temp", "Dewax 2 Temperature", 1, 1);
                   //
                   // Bind the PLC elements to the subscriber
                   DataSlowDewaxer1.PLCAddressValueItems.Add(Dewaxer1Temperature);
                   DataSlowDewaxer1.PLCAddressValueItems.Add(Dewaxer2Temperature);
                   //
                   // Example 2
                   // This is the other way. Create an array of a set number and then add in the form
                   PLCAddressItem[] DewaxerSlow = new PLCAddressItem[2]; // 2 item array (0 index)
                   //
                   // Initalize all of the PLC elements
                   for (int i = 0; i < DewaxerSlow.Count(); i++)
                   {
                       DewaxerSlow[i] = new PLCAddressItem();
                   }
                   //
                   // Set the PLC elements
                   DewaxerSlow[0].PLCAddress = "N7:0"; // Actual Address or tag name in the processor
                   DewaxerSlow[0].Description = "Example";
                   DewaxerSlow[0].Name = "Test"; // 
                   DewaxerSlow[0].ScaleOffset = 2; // This will offset the PLC value by plus 2 (NOTE: may use this if a sensor value is reading constantly offset)
                   DewaxerSlow[0].ScaleFactor = .50; // This will divide the PLC value by half (NOTE: may use this if you have to convert to a percentage)
                   //
                   DewaxerSlow[1].PLCAddress = "N7:2";
                   DewaxerSlow[1].Description = "Example2";
                   DewaxerSlow[1].Name = "Test2";
                   DewaxerSlow[1].ScaleOffset = 2;
                   DewaxerSlow[1].ScaleFactor = .50;
                   //
                   // add all of the PLC elements to the subscriber
                   for (var i = 0; i < DewaxerSlow.Count(); i++)
                   {
                       DataSlowDewaxer1.PLCAddressValueItems.Add(DewaxerSlow[i]);
                   }
                   //
                   // Subscriptions have been initalized
                   initalizeSub = true;
                   #endregion
               }
               #endregion
           }
           #region DataSubscribers (Set Data)
           #region Slow Subscriptions
           private void DataSlowDewaxer1_DataChanged(object sender, MfgControl.AdvancedHMI.Drivers.Common.PlcComEventArgs e)
           {
               if (e.ErrorId == 0)
               {
                   if (e.PlcAddress == "N7")
                   {
                       // map the value of this
                       // lbl_example.Text = e.Values[0];                    
                   }
               }
           }
           #endregion
           #region Medium Subscriptions
           private void DataMediumDewaxer1_DataChanged(object sender, MfgControl.AdvancedHMI.Drivers.Common.PlcComEventArgs e)
           {
               if (e.ErrorId == 0)
               {
                   if (e.PlcAddress == "N7")
                   {
                       // map the value of this
                       // lbl_example.Text = e.Values[0];
                   }
               }
           }
           #endregion
           #region Fast Subscriptions
           private void DataFastDewaxer1_DataChanged(object sender, MfgControl.AdvancedHMI.Drivers.Common.PlcComEventArgs e)
           {
               if (e.ErrorId == 0)
               {
                   if (e.PlcAddress == "N7")
                   {
                       // map the value of this
                       // lbl_example.Text = e.Values[0];
                   }
               }
           }
           #endregion
           #endregion
       }
   }