// This example shows how to read a Low state of a limit alarm. Note that you should not normally read a state of an alarm
// from inside its event notification, because the state might have already changed. Instead, include the information you
// need in the Select clauses when subscribing for the event.
 
using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Navigation;
 
namespace UADocExamples.AlarmsAndConditions
{
    class ReadAlarmState
    {
        public static void Main1()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";
 
            UANodeDescriptor alarmNodeDescriptor = new UANodeId(
                namespaceUriString:"http://opcfoundation.org/Quickstarts/AlarmCondition", 
                identifier:"1:Colours/EastTank?Yellow");
 
            // Knowing the alarm node, and the fact that is an instance of NonExclusiveLevelAlarmType (or its subtype),
            // determine what is its LowState/Id node.
            UANodeDescriptor lowStateIdNodeDescriptor = new UABrowsePath(alarmNodeDescriptor,
                new []
                {
                    UABrowsePathElement.CreateSimple("ns=0;s=LowState"),
                    UABrowsePathElement.CreateSimple("ns=0;s=Id")
                });
 
            // Instantiate the client object.
            var client = new EasyUAClient();
 
            Console.WriteLine("Reading alarm state...");
            var lowStateId = (bool)client.ReadValue(endpointDescriptor, lowStateIdNodeDescriptor);
 
            Console.WriteLine($"Id of LowState: {lowStateId}");
        }
    }
}