Strange Array/Object behaviour DataValue

fabi · 31 January 2023 07:28

I am using the node-red-contrib-opcua client node to read multiple variables at once. When i use node.warn() to debug the whole msg.payload array, i can access the different objects in it how i am used to it:

But when i try to access a single object directly, i get the following result:

Is there a way to convert this to an object?

Buckskin · 31 January 2023 18:59

try

node.warn(msg.payload[1])

fabi · 1 February 2023 06:08

This is what i tried. The unexpected result is in the second screenshot.

marcus-j-davies · 1 February 2023 09:41

Hi,

What version of Node RED are you using?
Any chance you can share the whole payload array JSON?

fabi · 1 February 2023 10:02

Hi, i am using Node-RED version 2.2.2. The payload array looks like this:

[{"value":{"dataType":"Boolean","arrayType":"Scalar","value":true},"statusCode":{"value":0},"sourceTimestamp":"2022-09-13T05:29:42.492Z","sourcePicoseconds":897000000,"serverTimestamp":"2022-09-13T05:29:42.492Z","serverPicoseconds":897000000},{"value":{"dataType":"Boolean","arrayType":"Scalar","value":false},"statusCode":{"value":0},"sourceTimestamp":"2022-09-13T05:29:42.492Z","sourcePicoseconds":997100000,"serverTimestamp":"2022-09-13T05:29:42.492Z","serverPicoseconds":997100000}]

jbudd · 1 February 2023 10:16

I see no problem (NR 3.0.2).

Nor do I see any data element called DataValue.
Can you show us the code that produces this output?

What do you mean by " access a single object directly"?

fabi · 1 February 2023 10:21

By acces a single object directly i mean msg.payload[1] instead of the whole array msg.payload. This is the Flow:

[{"id":"97628b22cec87e27","type":"tab","label":"OPCUA Excample","disabled":false,"info":"","env":[]},{"id":"c0bad6bc2c4de37a","type":"function","z":"97628b22cec87e27","name":"serialize","func":"let outputArr = msg.out;\nmsg = [outputArr];\n\nnode.warn(msg)\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":480,"y":180,"wires":[["10e5cce26a093390"]]},{"id":"f9c934ec5832f40b","type":"function","z":"97628b22cec87e27","name":"create target array","func":"\nconst targetArray = [\"ns=3;s=\\\"DB_OPCUA\\\".\\\"Roboter2\\\".\\\"Ampel\\\".\\\"rot\\\"\", \"ns=3;s=\\\"DB_OPCUA\\\".\\\"BinPicking\\\".\\\"Ampel\\\".\\\"gelb\\\"\"]\n\nconst outputArray = targetArray.map(elem => {\n    return {\n        topic: elem.toString()\n    }\n})\n\nmsg.out = outputArray;\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":290,"y":180,"wires":[["c0bad6bc2c4de37a"]]},{"id":"667ae29a94ccd7d3","type":"inject","z":"97628b22cec87e27","name":"","props":[],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":110,"y":180,"wires":[["f9c934ec5832f40b"]]},{"id":"10e5cce26a093390","type":"OpcUa-Client","z":"97628b22cec87e27","endpoint":"d36ff8a2b9f61387","action":"readmultiple","deadbandtype":"a","deadbandvalue":1,"time":10,"timeUnit":"s","certificate":"n","localfile":"","localkeyfile":"","securitymode":"None","securitypolicy":"None","folderName4PKI":"","name":"","x":700,"y":180,"wires":[["0c48a5bbf1a793bb"]]},{"id":"0c48a5bbf1a793bb","type":"function","z":"97628b22cec87e27","name":"output","func":"node.warn(msg.payload)\nnode.warn(msg.payload[1])","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":910,"y":180,"wires":[[]]},{"id":"d5f0659805b3e9c4","type":"function","z":"97628b22cec87e27","name":"readmultiple","func":"msg.payload = \"ALL\";\nmsg.topic = \"readmultiple\"\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":470,"y":260,"wires":[["10e5cce26a093390"]]},{"id":"27dff7c1a8644d14","type":"inject","z":"97628b22cec87e27","name":"","props":[],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":270,"y":260,"wires":[["d5f0659805b3e9c4"]]},{"id":"d36ff8a2b9f61387","type":"OpcUa-Endpoint","endpoint":"opc.tcp://192.168.1.110:4840","secpol":"None","secmode":"None","login":false}]

marcus-j-davies · 1 February 2023 10:30

I'm leaning towards some overload on the node internally.
it uses the flatted package - that does some stuff to aid in JSON structures.

its quite possible - when Node RED is parsing it - the node is overloading something, to produce the output.

doesn't explain when debugging payload though.

github.com

mikakaraila/node-red-contrib-opcua/blob/b01ee4ae05dfd4d200a64fc5c405a57b22435803/opcua/102-opcuaclient.js#L49


      
          var cloneDeep = require('lodash.clonedeep');
          var DataType = opcua.DataType;
          var AttributeIds = opcua.AttributeIds;
          // var read_service = require("node-opcua-service-read");
          var TimestampsToReturn = opcua.TimestampsToReturn;
          // var subscription_service = require("node-opcua-service-subscription");
          
          
const { createClientCertificateManager } = require("./utils");
          const { dumpCertificates } = require("./dump_certificates");
          
          
const {parse, stringify} = require('flatted');
          
          
function OpcUaClientNode(n) {
            RED.nodes.createNode(this, n);
            this.name = n.name;
            this.action = n.action;
            var originalAction = n.action;
            this.time = n.time;
            this.timeUnit = n.timeUnit;
            this.deadbandtype = n.deadbandtype;
            this.deadbandvalue = n.deadbandvalue;

very strange
I tested under 2.2.2 - and I don't get the same problem

jbudd · 1 February 2023 10:36

Using the data you posted and your "output" function
Untitled 1

[{"id":"f76632171fc65c2e","type":"inject","z":"afdab898a6a23bf5","name":"Fabi's array","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"value\":{\"dataType\":\"Boolean\",\"arrayType\":\"Scalar\",\"value\":true},\"statusCode\":{\"value\":0},\"sourceTimestamp\":\"2022-09-13T05:29:42.492Z\",\"sourcePicoseconds\":897000000,\"serverTimestamp\":\"2022-09-13T05:29:42.492Z\",\"serverPicoseconds\":897000000},{\"value\":{\"dataType\":\"Boolean\",\"arrayType\":\"Scalar\",\"value\":false},\"statusCode\":{\"value\":0},\"sourceTimestamp\":\"2022-09-13T05:29:42.492Z\",\"sourcePicoseconds\":997100000,\"serverTimestamp\":\"2022-09-13T05:29:42.492Z\",\"serverPicoseconds\":997100000}]","payloadType":"jsonata","x":210,"y":100,"wires":[["8c3b3cb619a849ad"]]},{"id":"1d0a83ed83fd300f","type":"debug","z":"afdab898a6a23bf5","name":"debug 257","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":530,"y":100,"wires":[]},{"id":"8c3b3cb619a849ad","type":"function","z":"afdab898a6a23bf5","name":"output","func":"node.warn(msg.payload)\nnode.warn(msg.payload[1])","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":370,"y":100,"wires":[["1d0a83ed83fd300f"]]}]

I get this

What does this flow output for you?

fabi · 1 February 2023 10:38

With your flow i get the exact same output as you.

jbudd · 1 February 2023 10:40

Then perhaps a debug node set to show the complete message coming out of your opcua node might shed some light?

I think @marcus-j-davies knows more about this than me since I don't use opcua.

fabi · 1 February 2023 10:43

that is the complete message of the opcua node after i read the stored nodeIds

{"topic":"ALL","payload":[{"value":{"dataType":"Boolean","arrayType":"Scalar","value":true},"statusCode":{"value":0},"sourceTimestamp":"2022-09-13T06:10:17.878Z","sourcePicoseconds":972500000,"serverTimestamp":"2022-09-13T06:10:17.878Z","serverPicoseconds":972500000},{"value":{"dataType":"Boolean","arrayType":"Scalar","value":false},"statusCode":{"value":0},"sourceTimestamp":"2022-09-13T06:10:17.879Z","sourcePicoseconds":113400000,"serverTimestamp":"2022-09-13T06:10:17.879Z","serverPicoseconds":113400000}],"items":[{"nodeId":"ns=3;s=\"DB_OPCUA\".\"Roboter2\".\"Ampel\".\"rot\"","attributeId":13,"TimestampsToReturn":2},{"nodeId":"ns=3;s=\"DB_OPCUA\".\"BinPicking\".\"Ampel\".\"gelb\"","attributeId":13,"TimestampsToReturn":2}],"_msgid":"4cc97809d157ba26"}

jbudd · 1 February 2023 10:51

I don't see any problem when I feed that payload into your output node, sorry.

fabi · 1 February 2023 10:52

Thank you anyways for your help and your time!

marcus-j-davies · 1 February 2023 10:52

I'm pretty sure, the node is overloading the output during stringify.

The below demos it - it doesn't fully explain the behaviour, but its all I have.

[{"id":"a7efc2d9be2f1751","type":"tab","label":"Flow 1","disabled":false,"info":"","env":[]},{"id":"1cd906e5aef9b6b5","type":"inject","z":"a7efc2d9be2f1751","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":165,"y":150,"wires":[["0ed656291449cc9b"]]},{"id":"0ed656291449cc9b","type":"function","z":"a7efc2d9be2f1751","name":"Array","func":"return {\n  \"topic\": \"ALL\",\n  \"payload\": [\n    {\n      toJSON: function(){\n        return{\n          payload: \"Not what you expect\"\n        }\n      },\n      \"value\": {\n        \"dataType\": \"Boolean\",\n        \"arrayType\": \"Scalar\",\n        \"value\": true\n      },\n      \"statusCode\": {\n        \"value\": 0\n      },\n      \"sourceTimestamp\": \"2022-09-13T06:10:17.878Z\",\n      \"sourcePicoseconds\": 972500000,\n      \"serverTimestamp\": \"2022-09-13T06:10:17.878Z\",\n      \"serverPicoseconds\": 972500000\n    },\n    {\n      \"value\": {\n        \"dataType\": \"Boolean\",\n        \"arrayType\": \"Scalar\",\n        \"value\": false\n      },\n      \"statusCode\": {\n        \"value\": 0\n      },\n      \"sourceTimestamp\": \"2022-09-13T06:10:17.879Z\",\n      \"sourcePicoseconds\": 113400000,\n      \"serverTimestamp\": \"2022-09-13T06:10:17.879Z\",\n      \"serverPicoseconds\": 113400000\n    }\n  ],\n  \"items\": [\n    {\n      \"nodeId\": \"ns=3;s=\\\"DB_OPCUA\\\".\\\"Roboter2\\\".\\\"Ampel\\\".\\\"rot\\\"\",\n      \"attributeId\": 13,\n      \"TimestampsToReturn\": 2\n    },\n    {\n      \"nodeId\": \"ns=3;s=\\\"DB_OPCUA\\\".\\\"BinPicking\\\".\\\"Ampel\\\".\\\"gelb\\\"\",\n      \"attributeId\": 13,\n      \"TimestampsToReturn\": 2\n    }\n  ],\n}","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":235,"y":340,"wires":[["3d6261a6c24b0a21"]]},{"id":"3d6261a6c24b0a21","type":"function","z":"a7efc2d9be2f1751","name":"node warn (0)","func":"node.warn(msg.payload[0])","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":465,"y":340,"wires":[[]]}]

fabi · 1 February 2023 11:57

Thank you also for your answer. My temporary solution is to do node.warn(msg.payload[1].toJSON())
to get the expected result.

bakman2 · 1 February 2023 17:04

Are you actually using node-red and not some kind of variant ?

fabi · 2 February 2023 05:57

I am using it in a Docker Container but should be the normal version of Node-RED.

system · 3 April 2023 05:57

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.

Topic		Replies	Views
Parsing Payload General function-node	15	635	17 February 2023
Converting msg.payload array into an object to access its value General	4	1086	12 October 2022
Payload Object read out General	5	739	27 February 2021
How to read and parse object names in node-red? General node-red-dashboard , function-node	2	361	21 November 2022
Access the object General function-node	23	219	28 December 2022

Strange Array/Object behaviour DataValue

Related Topics