// This example shows how to adjust to sampling interval changes in the push data provision model.
// You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-OPCStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.
using System;
using System.Threading;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;
using Timer = System.Timers.Timer;
namespace UAServerDocExamples._UAServerNode
{
class SamplingIntervalChanged
{
public static void Main1()
{
// Instantiate the server object.
// By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
var server = new EasyUAServer();
// Create a timer for pushing the data for OPC reads. In a real server the activity may also come from other
// sources.
var timer = new Timer { AutoReset = true };
// Create a read-only data variable.
var dataVariable = UADataVariable.CreateIn(server.Objects, "SubscribeToThisVariable")
.ValueType<int>()
.Writable(false);
dataVariable.SamplingIntervalChanged += (sender, args) =>
{
// Obtain and display the new sampling interval.
int samplingInterval = dataVariable.SamplingInterval;
Console.WriteLine($"Sampling interval changed to: {samplingInterval}");
// Adjust the timer interval accordingly. If the sampling interval is infinite, stop the timer. Otherwise,
// set the timer interval to half of the sampling interval, but at least 1 millisecond, and start the timer.
if (samplingInterval == Timeout.Infinite)
timer.Enabled = false;
else
{
timer.Interval = Math.Max(samplingInterval/2, 1);
timer.Enabled = true;
}
args.Handled = true;
};
// Set the read attribute data of the data variable to a random value whenever the timer interval elapses.
var random = new Random();
timer.Elapsed += (sender, args) => dataVariable.UpdateReadAttributeData(random.Next());
// Start the server.
Console.WriteLine("The server is starting...");
server.Start();
Console.WriteLine("The server is started.");
Console.WriteLine();
// Let the user decide when to stop.
Console.WriteLine("Press Enter to stop the server...");
Console.ReadLine();
// Stop the server.
Console.WriteLine("The server is stopping...");
server.Stop();
// Stop the timer.
timer.Stop();
Console.WriteLine("The server is stopped.");
}
}
}