Data Conversion - Java Script Expression - EtherNetIP node

General
1

I am reading PLC tags using the Ethernet/IP node. The output is something like:

{Recipe.Ingredient[0]: 1234.5, Recipe.Ingredient[1]: 678.9}

There will be hundreds of tags.

Right now, I can read them and get a nice log.csv

I cannot, however use the tags (values).

I think I'd have the same problem if I read from log.csv as well?

I don't have a problem when I read an atomic data type. I have an entire data structure map. I just can't reference these array members as "msg.payload.Recipe.Ingredient[0]". I can reference the tag "Ingredient_12_Weight" by "var Ingredient12Weight=msg.payload.Ingredient_12_Weight".

If what I'm trying to do is possible, I think it's pretty simple for a good js programmer. It's hard to believe that it's not possible.

2

Welcome to the forum.

Feed the message into a debug node and expand it enough that we can see the format of the data and post a screenshot here.

Have you read the node red docs page Working with Messages? It shows you how to get the path to properties from the debug pane.

3

I've posted screenshots of the flow that works with Atomic tags and the flow that doesn't when I try to use Array/UDT Tags.

So far, my best solution is to use the CSV node to strip header names and then another CSV node to add new headers without "." or "[", or "]".

AtomicOnly
AtomicOnly1362Ă—472 26.6 KB
EIP_SIM_DATA
Problem
Problem1460Ă—406 23.3 KB
Structure_Atomic
Structure_Atomic563Ă—574 14.3 KB
Structure_Problem
Structure_Problem591Ă—575 14.2 KB

4 
[{"id":"69adde37.42636","type":"tab","label":"EIP_TagError","disabled":false,"info":""},{"id":"57f9dae4.fbcfc4","type":"debug","z":"69adde37.42636","name":"EIP_Debug","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":670,"y":260,"wires":[]},{"id":"b6fcfc11.0173d","type":"function","z":"69adde37.42636","name":"EIP DATA SIM","func":"\n    \nmsg.payload = {\n\"TestTag1\":1.11,\n\"TestTag2\":2.22,\n\"ActiveRecipe.Ingredient[0]\":3.33,\n\"ActiveRecipe.Ingredient[1]\":4.44,\n\"ActiveRecipe.Ingredient[2]\":5.55\n    }\n    \n    \nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":440,"y":260,"wires":[["57f9dae4.fbcfc4","e680d9b2.5de2a8"]]},{"id":"6e7b7fee.901cd","type":"inject","z":"69adde37.42636","name":"PokeTest","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":240,"y":260,"wires":[["b6fcfc11.0173d"]]},{"id":"e680d9b2.5de2a8","type":"function","z":"69adde37.42636","name":"Structure","func":"\nlet Test1=msg.payload.TestTag1;\nlet Test2=msg.payload.TestTag2;\n\n//let Test3=msg.payload.ActiveRecipe.Ingredient[0];\n//let Test4=msg.payload.ActiveRecipe.Ingredient[1];\n//let Test5=msg.payload.ActiveRecipe.Ingredient[2];\n\n\nmsg.payload={\n    \"WarpSpeedEfficiencyFactor\":Test1,\n    \"HyperDriveSuperConductorTemperature (K)\":Test2,\n//    \"SimpleTest1\":Test3,\n//    \"SimpleTest2\":Test4,\n//    \"SimpleTest3\":Test5\n}\n\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":660,"y":320,"wires":[["3a1826a2.a6a26a"]]},{"id":"3a1826a2.a6a26a","type":"debug","z":"69adde37.42636","name":"Structure_Debug","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":890,"y":320,"wires":[]}]
5

If you have property names (which I think is what you mean by tags) with special characters in then you have to use the square bracket notation rather than the dot shorthand. msg.payload is a shorthand way of writing msg["payload"]. So your function needs to be something like

let Test1=msg.payload.TestTag1;
let Test2=msg.payload.TestTag2;

let Test3=msg.payload["ActiveRecipe.Ingredient[0]"];
let Test4=msg.payload["ActiveRecipe.Ingredient[1]"];
let Test5=msg.payload["ActiveRecipe.Ingredient[2]"];


msg.payload={
    "WarpSpeedEfficiencyFactor":Test1,
    "HyperDriveSuperConductorTemperature (K)":Test2,
    "SimpleTest1":Test3,
    "SimpleTest2":Test4,
    "SimpleTest3":Test5
}

return msg;
1 Like
6

Are you sure you don't what ActiveRecipe to be an object containing an Ingredient array?

7

Ingredient is an array that is a member of ActiveRecipe in the PLC which is the source of my data.

let Test1=msg.payload.TestTag1;
let Test2=msg.payload.TestTag2;

let Test3=msg.payload["ActiveRecipe.Ingredient[0]"];
let Test4=msg.payload["ActiveRecipe.Ingredient[1]"];
let Test5=msg.payload["ActiveRecipe.Ingredient[2]"];

msg.payload={
"WarpSpeedEfficiencyFactor":Test1,
"HyperDriveSuperConductorTemperature (K)":Test2,
"SimpleTest1":Test3,
"SimpleTest2":Test4,
"SimpleTest3":Test5
}

return msg;

I had to add quotes as well but now it works. Thank you so much.

8

It may be an array in the plc but it is not an array in the code you posted.

This code that you posted

msg.payload = {
"TestTag1":1.11,
"TestTag2":2.22,
"ActiveRecipe.Ingredient[0]":3.33,
"ActiveRecipe.Ingredient[1]":4.44,
"ActiveRecipe.Ingredient[2]":5.55
    }

creates a property in msg.payload called ActiveRecipe.Ingredient[0]. If you wanted to create an array you would use

msg.payload = {
"TestTag1":1.11,
"TestTag2":2.22,
"ActiveRecipe": {"Ingredient": [3.33, 4.44, 5.55]}
}

Then your original code would work

let Test3=msg.payload.ActiveRecipe.Ingredient[0];
let Test4=msg.payload.ActiveRecipe.Ingredient[1];
let Test5=msg.payload.ActiveRecipe.Ingredient[2];

What quotes did you have to add?

9

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.