I use node-opcua module and I would like to monitor many opc ua nodes with subscription I see result like: user in html UI choose what nodes to monitor, then click Monitor button that sent these nodeIds as parameters and then for every nodeid will be set subscription and .on("changed") works for every of these items like in parallel. Now code looks like:

 var monitoredItem  = the_subscription.monitor({
       nodeId: opcua.resolveNodeId("ns=6;s=S71500ET200MP station_1.Master.111"),
       attributeId: 13
   },
   {
       samplingInterval: 100,
       discardOldest: true,
       queueSize: 10
   },
   opcua.read_service.TimestampsToReturn.Both
   );
   console.log("-------------------------------------");
   var nodes = [];

   monitoredItem.on("changed",function(dataValue){
      //console.log(" value = ",dataValue.value.value);
      //console.log(" sourceTimestamp = ",dataValue.sourceTimestamp.toISOString());
      //console.log(JSON.stringify(dataValue));
      var Node = {nodeId: "ns=6;s=S71500ET200MP station_1.Master.111", nodeName: "111" , nodeValue: dataValue.value.value , nodeTimestamp: dataValue.sourceTimestamp.toISOString()};
      var arrayNode = Object.keys(Node).map(function(k) { return Node[k] });
      //console.log(JSON.stringify(Node));
      nodes.push(arrayNode);

    //  console.log(nodes);
   });
},

Right now if I want to set new item to monitor it just add many vars MonitorItem1 , ..2 , ..3 etc.

How to do it in more agile/dynamic way? if I have array(strings) of nodeIds and I want each of these to be monitored in subscription. Code is part of async.series([ code ])

I use node-opcua module and I would like to monitor many opc ua nodes with subscription I see result like: user in html UI choose what nodes to monitor, then click Monitor button that sent these nodeIds as parameters and then for every nodeid will be set subscription and .on("changed") works for every of these items like in parallel. Now code looks like:

 var monitoredItem  = the_subscription.monitor({
       nodeId: opcua.resolveNodeId("ns=6;s=S71500ET200MP station_1.Master.111"),
       attributeId: 13
   },
   {
       samplingInterval: 100,
       discardOldest: true,
       queueSize: 10
   },
   opcua.read_service.TimestampsToReturn.Both
   );
   console.log("-------------------------------------");
   var nodes = [];

   monitoredItem.on("changed",function(dataValue){
      //console.log(" value = ",dataValue.value.value);
      //console.log(" sourceTimestamp = ",dataValue.sourceTimestamp.toISOString());
      //console.log(JSON.stringify(dataValue));
      var Node = {nodeId: "ns=6;s=S71500ET200MP station_1.Master.111", nodeName: "111" , nodeValue: dataValue.value.value , nodeTimestamp: dataValue.sourceTimestamp.toISOString()};
      var arrayNode = Object.keys(Node).map(function(k) { return Node[k] });
      //console.log(JSON.stringify(Node));
      nodes.push(arrayNode);

    //  console.log(nodes);
   });
},

Right now if I want to set new item to monitor it just add many vars MonitorItem1 , ..2 , ..3 etc.

How to do it in more agile/dynamic way? if I have array(strings) of nodeIds and I want each of these to be monitored in subscription. Code is part of async.series([ code ])

• javascript
• node.js
• opc-ua
• node-opcua

Share Improve this question Follow edited Jan 5, 2016 at 23:46 Etienne 16.9k33 gold badges2929 silver badges3232 bronze badges asked Dec 19, 2015 at 17:17 leonas5555leonas5555 8311 silver badge99 bronze badges 0

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2 Answers 2

Sorted by: Reset to default 3

solved using async.each method

async.each(nodeIdArr, function(nodeid, callback) {

     var monitoredItem  = the_subscription.monitor({
           nodeId: opcua.resolveNodeId(nodeid),
           attributeId: 13
       },
       {
           samplingInterval: 100,
           discardOldest: true,
           queueSize: 10
       },
       opcua.read_service.TimestampsToReturn.Both
       );
       console.log("-------------------------------------");


       monitoredItem.on("changed",function(dataValue){
          //console.log(" value = ",dataValue.value.value);
          //console.log(" sourceTimestamp = ",dataValue.sourceTimestamp.toISOString());
          //console.log(JSON.stringify(dataValue));
          var Node = {nodeId: nodeid, nodeName: "111" , nodeValue: dataValue.value.value , nodeTimestamp: dataValue.sourceTimestamp.toISOString()};
          var arrayNode = Object.keys(Node).map(function(k) { return Node[k] });
          //console.log(JSON.stringify(Node));
          nodes.push(arrayNode);

        //  console.log(nodes);
      });

Now you can use the method the_subscription.monitorItems()