# Inject dynamical variables in a node
**URL:** https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957
**Category:** Industrial
**Created:** [27 February 2024 14:14 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957 "2024-02-27T14:14:00Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@MystiiK](https://discourse.nodered.org/u/MystiiK)
#### Post date: [27 February 2024 14:14 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/1 "2024-02-27T14:14:00Z")
Hello,
I read data from an electronic card integrated in a climatic chamber.
I use the node-red-contrib-telnet-client to do that (I can't use s7 nodes for example).
Because we have multiples chambers, I created an object (in a function) where there is the list of the chambers with their own properties (IP address, name, port). In the telnet nodes, I would like to inject these parameters in the fields, and not directly a value. In fact, I would like to establish the connection for one chamber, then read and treat data, and finally wait a little in order to do this cycle for each chamber (the delay is here for avoiding communication saturation).
How could I make a loop for this ? I just have to change the 3 fields in the "Connection" field of the telnet node. For instance, in the "Port" field in the telnet node, I can only put a number value. I can not enter a parameter like "msg.payload.port".
Here is my function with the list of the chambers :
```auto
let Etuves = {
nomEtuve: "",
adresseIP: "",
port: 888,
}
let etuve217 = Object.create(Etuves);
etuve217.nomEtuve = "Etuve 217";
etuve217.adresseIP = "xx.xx.xx.217";
let etuve109 = Object.create(Etuves);
etuve109.nomEtuve = "Etuve 109";
etuve109.adresseIP = "xx.xx.xx.109";
let etuve111 = Object.create(Etuves);
etuve111.nomEtuve = "Etuve 111";
etuve111.adresseIP = "xx.xx.xx.111";
let etuve216 = Object.create(Etuves);
etuve216.nomEtuve = "Etuve 216";
etuve216.adresseIP = "xx.xx.xx.216";
let tab = [];
tab.push(etuve217)
tab.push(etuve109)
tab.push(etuve111)
tab.push(etuve216)
return {payload: tab}
```
You will find below the flow :
```auto
[
{
"id": "1a7e315fd340af0f",
"type": "tab",
"label": "Flow 3",
"disabled": false,
"info": "",
"env": []
},
{
"id": "a8c1d9281aea0673",
"type": "function",
"z": "1a7e315fd340af0f",
"name": "List of the chambers",
"func": "let Etuves = {\n nomEtuve: \"\",\n adresseIP: \"\",\n port: 888,\n}\n\n\n\nlet etuve217 = Object.create(Etuves);\netuve217.nomEtuve = \"Etuve 217\";\netuve217.adresseIP = \"xx.xx.xx.217\";\n\n\nlet etuve109 = Object.create(Etuves);\netuve109.nomEtuve = \"Etuve 109\";\netuve109.adresseIP = \"xx.xx.xx.109\";\n\n\nlet etuve111 = Object.create(Etuves);\netuve111.nomEtuve = \"Etuve 111\";\netuve111.adresseIP = \"xx.xx.xx.111\";\n\n\nlet etuve216 = Object.create(Etuves);\netuve216.nomEtuve = \"Etuve 216\";\netuve216.adresseIP = \"xx.xx.xx.216\";\n\n\nlet tab = [];\ntab.push(etuve217)\ntab.push(etuve109)\ntab.push(etuve111)\ntab.push(etuve216)\n\nreturn {payload: tab}\n\n",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 600,
"y": 360,
"wires": [
[
"133e8899145a6ab6",
"a690ba198e52db7e"
]
]
},
{
"id": "32fa05f1e9c7c923",
"type": "inject",
"z": "1a7e315fd340af0f",
"name": "Fake Data",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "56",
"payloadType": "num",
"x": 400,
"y": 360,
"wires": [
[
"a8c1d9281aea0673"
]
]
},
{
"id": "2b5a428a194e0fc4",
"type": "debug",
"z": "1a7e315fd340af0f",
"name": "",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "true",
"targetType": "full",
"statusVal": "",
"statusType": "auto",
"x": 1050,
"y": 280,
"wires": []
},
{
"id": "133e8899145a6ab6",
"type": "change",
"z": "1a7e315fd340af0f",
"name": "",
"rules": [
{
"t": "set",
"p": "listeEtuves",
"pt": "global",
"to": "tab",
"tot": "msg"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 860,
"y": 360,
"wires": [
[
"2b5a428a194e0fc4",
"16e8c2f9e428e79c"
]
]
},
{
"id": "a690ba198e52db7e",
"type": "debug",
"z": "1a7e315fd340af0f",
"name": "",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 830,
"y": 280,
"wires": []
},
{
"id": "4cc7ebb845e3a096",
"type": "telnet-send",
"z": "1a7e315fd340af0f",
"name": "",
"connection": "27ace6a62991b9b0",
"x": 1230,
"y": 360,
"wires": []
},
{
"id": "a4df93d5b4be84e1",
"type": "telnet-read",
"z": "1a7e315fd340af0f",
"name": "",
"connection": "",
"x": 1230,
"y": 420,
"wires": [
[
"e1a6047482ce5f0e"
]
]
},
{
"id": "e1a6047482ce5f0e",
"type": "debug",
"z": "1a7e315fd340af0f",
"name": "",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "false",
"statusVal": "",
"statusType": "auto",
"x": 1390,
"y": 420,
"wires": []
},
{
"id": "16e8c2f9e428e79c",
"type": "delay",
"z": "1a7e315fd340af0f",
"name": "",
"pauseType": "delay",
"timeout": "10",
"timeoutUnits": "milliseconds",
"rate": "1",
"nbRateUnits": "1",
"rateUnits": "second",
"randomFirst": "1",
"randomLast": "5",
"randomUnits": "seconds",
"drop": false,
"allowrate": false,
"outputs": 1,
"x": 1070,
"y": 360,
"wires": [
[
"4cc7ebb845e3a096"
]
]
},
{
"id": "27ace6a62991b9b0",
"type": "telnet-connection",
"name": "",
"address": "127.0.0.1",
"port": "23",
"inDelimiter": "",
"outDelimiter": "",
"timeOut": "1500",
"clearOut": "",
"openTries": "1"
}
]
```
I am still a beginner in Javascript, so maybe there is a more efficient way to do this function.
Thank you for your help 🙂
---
### Author:  [@MystiiK](https://discourse.nodered.org/u/MystiiK)
#### Post date: [29 February 2024 11:50 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/2 "2024-02-29T11:50:15Z")
Hi, I come back to my previous message.
In fact, due to the impossibility to inject dynamical variables, I can't factorise the code like I wanted. The solution I've found is to create send and read data nodes for each chamber. However, the processing of data can be done in a subflow in order to shorten the code. The problem is the using of global variables in the subflow. I noticed that the values for both chambers are well read, but they are replaced when the same parameter is read of the next chamber. For instance, I would like to print the pressure value of the first and the second chamber. In my case, it prints first :
```auto
"Chamber 1 : 10.09"
"Chamber 2 : 10.09"
```
And then :
```auto
"Chamber 1 : 13.49"
"Chamber 2 : 13.49"
```
I would like to get :
```auto
"Chamber 1 : 10.09"
"Chamber 2 : 13.49"
```
Do you know how can I fix this problem ? I did one processing for each chamber, so I thought it will give me the value for each one. But apparently, it is not the case. Here is an idea of my flow.
In the subflow, I only have a change node which sets a global value for one parameter.
I hope it was clear, but I definitely think that the problem comes from global values.
Flow :
```auto
[
{
"id": "2c411b946746dd66",
"type": "subflow",
"name": "Subflow 1",
"info": "",
"in": [
{
"x": 380,
"y": 280,
"wires": [
{
"id": "f22cb29dee88cede"
}
]
}
],
"out": [
{
"x": 880,
"y": 280,
"wires": [
{
"id": "f22cb29dee88cede",
"port": 0
}
]
}
]
},
{
"id": "f22cb29dee88cede",
"type": "change",
"z": "2c411b946746dd66",
"name": "",
"rules": [
{
"t": "set",
"p": "Etuve.MHpPrinc",
"pt": "global",
"to": "msg.payload",
"tot": "jsonata"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 620,
"y": 280,
"wires": [
[]
]
},
{
"id": "2e1fb91b064e0dbb",
"type": "tab",
"label": "Flow 4",
"disabled": false,
"info": "",
"env": []
},
{
"id": "8e3b11bfdc086999",
"type": "inject",
"z": "2e1fb91b064e0dbb",
"name": "Fake data",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "10",
"crontab": "",
"once": true,
"onceDelay": 0.1,
"topic": "",
"payload": "56",
"payloadType": "num",
"x": 510,
"y": 440,
"wires": [
[
"a05f0162842cae4d",
"40088b6b39ea021c"
]
]
},
{
"id": "40088b6b39ea021c",
"type": "telnet-send",
"z": "2e1fb91b064e0dbb",
"name": "",
"connection": "8a3cd99875508432",
"x": 750,
"y": 380,
"wires": []
},
{
"id": "5b1dc18d931f5d53",
"type": "telnet-read",
"z": "2e1fb91b064e0dbb",
"name": "",
"connection": "8a3cd99875508432",
"x": 1010,
"y": 380,
"wires": [
[
"5fa05bac2447ebfe"
]
]
},
{
"id": "a05f0162842cae4d",
"type": "telnet-send",
"z": "2e1fb91b064e0dbb",
"name": "",
"connection": "1834e5b8655e71f1",
"x": 750,
"y": 520,
"wires": []
},
{
"id": "35d4f0aaad4e1ed6",
"type": "telnet-read",
"z": "2e1fb91b064e0dbb",
"name": "",
"connection": "1834e5b8655e71f1",
"x": 1010,
"y": 520,
"wires": [
[
"ca8f57ae883f8f1b"
]
]
},
{
"id": "6ffbf644f4de15a4",
"type": "debug",
"z": "2e1fb91b064e0dbb",
"name": "Chamber 1",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 1390,
"y": 380,
"wires": []
},
{
"id": "bc9e4410b64aac46",
"type": "debug",
"z": "2e1fb91b064e0dbb",
"name": "Chamber 2",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 1390,
"y": 480,
"wires": []
},
{
"id": "f1b525c41d22ab3c",
"type": "ui_text",
"z": "2e1fb91b064e0dbb",
"group": "7b5442934adeb0ca",
"order": 1,
"width": 6,
"height": 1,
"name": "",
"label": "MHpPrinc 1",
"format": "{{msg.payload}}",
"layout": "row-center",
"className": "",
"x": 1390,
"y": 420,
"wires": []
},
{
"id": "74258a789825c2c3",
"type": "ui_text",
"z": "2e1fb91b064e0dbb",
"group": "7b5442934adeb0ca",
"order": 1,
"width": 6,
"height": 1,
"name": "",
"label": "MHpPrinc 2",
"format": "{{msg.payload}}",
"layout": "row-center",
"className": "",
"x": 1390,
"y": 520,
"wires": []
},
{
"id": "ac54dc8d04b57ac6",
"type": "comment",
"z": "2e1fb91b064e0dbb",
"name": "Chamber 1",
"info": "",
"x": 880,
"y": 380,
"wires": []
},
{
"id": "75b10e05ba2ef27c",
"type": "comment",
"z": "2e1fb91b064e0dbb",
"name": "Chamber 2",
"info": "",
"x": 880,
"y": 520,
"wires": []
},
{
"id": "5fa05bac2447ebfe",
"type": "subflow:2c411b946746dd66",
"z": "2e1fb91b064e0dbb",
"name": "",
"x": 1180,
"y": 380,
"wires": [
[
"6ffbf644f4de15a4",
"f1b525c41d22ab3c"
]
]
},
{
"id": "ca8f57ae883f8f1b",
"type": "subflow:2c411b946746dd66",
"z": "2e1fb91b064e0dbb",
"name": "",
"x": 1180,
"y": 520,
"wires": [
[
"bc9e4410b64aac46",
"74258a789825c2c3"
]
]
},
{
"id": "8a3cd99875508432",
"type": "telnet-connection",
"name": "Chamber 1",
"address": "127.0.0.1",
"port": "23",
"inDelimiter": "",
"outDelimiter": "",
"timeOut": "1500",
"clearOut": "",
"openTries": "1"
},
{
"id": "1834e5b8655e71f1",
"type": "telnet-connection",
"name": "Chamber 2",
"address": "127.0.0.2",
"port": "23",
"inDelimiter": "",
"outDelimiter": "",
"timeOut": "1500",
"clearOut": "",
"openTries": "1"
},
{
"id": "7b5442934adeb0ca",
"type": "ui_group",
"name": "Group 1",
"tab": "81690565567bb45b",
"order": 1,
"disp": true,
"width": 9
},
{
"id": "81690565567bb45b",
"type": "ui_tab",
"name": "TEST",
"icon": "dashboard",
"order": 5,
"disabled": false,
"hidden": false
}
]
```
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [29 February 2024 11:56 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/3 "2024-02-29T11:56:43Z")
Your subflow is completely meaningless - it sets a global variable and nothing more
It is the payload value from these `read` nodes that set your UI elements.
that should be evident by the output of the debug nodes.
---
### Author:  [@MystiiK](https://discourse.nodered.org/u/MystiiK)
#### Post date: [29 February 2024 13:44 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/4 "2024-02-29T13:44:58Z")
Thanks for your reply.
I put only one value in the subflow for the example, but there are many others variables in my real flow. I also do some processing within it. That is why I created a subflow. There are multiples payload within it. Otherwise yes, the subflow would be meaningless.
This is an extract of my subflow. As you see, I define a global name for each parameter. For instance, I defined _Etuve.MHpPrinc_, then I send the value by MQTT. Doing that within the subflow, I thought it will give me the value for every chamber, because their is one subflow linked to one chamber (see flow).
I can't achieve to print the value of _Etuve.MHpPrinc_ for the chamber 1 and 2 separately, it's either 1 or 2.
Does it more clear ?
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [29 February 2024 13:50 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/5 "2024-02-29T13:50:57Z")
output 1 will be triggered for EVERY subflow.
either move the MQTT stuff out of the subflow OR test the topic using a switch node AFTER the subflow.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [14 March 2024 13:51 UTC](https://discourse.nodered.org/t/inject-dynamical-variables-in-a-node/85957/6 "2024-03-14T13:51:41Z")
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