Example with deadband on timestamp not working.

opcua.js

/*global require,console,setTimeout */
var opcua = require("node-opcua");
var async = require("async");

var config = {
  "server": "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer",
  "tags": [{
//    "name": "An Int32",
//    "nodeId": "ns=2;i=10849",
//    "updateInterval": 100
//  }, {
//    "name": "A String",c
//    "nodeId": "ns=2;i=10855",
//    "updateInterval": 3000
//  }, {
    "name": "An Int16",
    "nodeId": "ns=2;i=10219",
    "updateInterval": 1000
  }]
};

var client = new opcua.OPCUAClient();

var the_session, the_subscription;

async.series([

    // step 1 : connect to
    function(callback) {
      var endpointURL = config.server;
      client.connect(endpointURL, function(err) {
        if (err) {
          console.log("Cannot connect to endpoint [", endpointURL, "].");
        } else {
          console.log("Succesfully connected to server [", endpointURL, "]!");
        }
        callback(err);
      });
    },

    // step 2 : createSession
    function(callback) {
      client.createSession(function(err, session) {
        if (!err) {
          the_session = session;
        }
        callback(err);
      });
    },
    // step 4' : check if all the specified nodes are readable.
    function(callback) {
      var max_age = 0;
      var nodes_to_read = [];
      config.tags.forEach(function(tag) {
        var node = {
          nodeId: tag.nodeId,
          attributeId: opcua.AttributeIds.Value
        };
        nodes_to_read.push(node);
      });
      the_session.read(nodes_to_read, max_age, function(err, nodes_to_read, dataValues) {
        if (!err) {
          dataValues.forEach(function(datavalue, i) {
            var sc = datavalue.statusCode
            if (sc.value == 0) {
              console.log("Tag [", config.tags[i].name , "] verified. Value = [", datavalue.value.value, "].");
            } else {
              console.log("Tag [", config.tags[i].name , "] could not be read. Status = [", sc.name, "], Description = [", sc.description, "].");
            }           
          })
        }
        callback(err);
      });
    },

    // step 5: install a subscription and install a monitored item for X seconds
    function(callback) {

      the_subscription = new opcua.ClientSubscription(the_session, {
        requestedPublishingInterval: 1000,
        requestedLifetimeCount: 10,
        requestedMaxKeepAliveCount: 2,
        maxNotificationsPerPublish: 1,
        publishingEnabled: true,
        priority: 10
      });

      the_subscription.on("started", function() {
        console.log("subscription started for 2 seconds - subscriptionId=", the_subscription.subscriptionId);
      }).on("keepalive", function() {
        console.log("keepalive");
      }).on("terminated", function() {
        callback();
      });

      setTimeout(function() {
        the_subscription.terminate();
      }, 7200000);
      
      config.tags.forEach(function(tag) {
        // install monitored item
        var monitoredItem = the_subscription.monitor({
            nodeId: opcua.resolveNodeId(tag.nodeId),
            attributeId: opcua.AttributeIds.Value
          }, {
            clienthandle: 13,
            samplingInterval: tag.updateInterval,
            filter: new opcua.subscription_service.DataChangeFilter({
              trigger: opcua.subscription_service.DataChangeTrigger.StatusValueTimestamp,
              deadbandType: opcua.subscription_service.DeadbandType.Absolute,
              deadbandValue: 5000
            }),
            discardOldest: true,
            queueSize: 10
          },
          opcua.read_service.TimestampsToReturn.Both
          , function(err){
            console.log("ERR ", err);
          }
        );
        
        monitoredItem.on("changed", function(dataValue) {
          var value = {
            "value": dataValue.value.value,
            "time": dataValue.sourceTimestamp.getTime()
          };
          var tags = {
            "opcstatus": dataValue.statusCode.value
          };
          console.log(tag.name, value);          
        });
        monitoredItem.on("err", function (err_message) {
            console.log(monitoredItem.itemToMonitor.nodeId.toString(), " ERROR".red, err_message);
       });
        
        tag.monitoredItem = monitoredItem;
      });
    },

    // close session
    function(callback) {
      the_session.close(function(err) {
        if (err) {
          console.log("session closed failed ?");
        }
        callback();
      });
    }

  ],
  function(err) {
    if (err) {
      console.log(" failure ", err);
    } else {
      console.log("done!");
    }
    client.disconnect(function() {});
  });