Split a value into two values

Becker · 8 April 2021 13:31

Hi guys,
today I have a very simple question for you:
I´ve a value that varies between +2600 and -2500.
I would like to distinguish this into two new values: if <0 than var "Unloading", if> 0 than var "Loading".

but unfortunately I can't do it

thanks for help.

Becker · 8 April 2021 13:37

I think I got it with "split":

[{"id":"b6efc276.3b37","type":"switch","z":"9f6752b0.b55988","name":"","property":"payload.PAC3","propertyType":"msg","rules":[{"t":"gte","v":"0","vt":"num"},{"t":"lt","v":"0","vt":"num"}],"checkall":"true","repair":false,"outputs":2,"x":1430,"y":1940,"wires":[["4d18ea91.fe6d24"],["fbb45a39.7ca4d8"]]},{"id":"4d18ea91.fe6d24","type":"function","z":"9f6752b0.b55988","name":"","func":"msg.payload = msg.payload.PAC3;\nmsg.topic = \"Entladen\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1580,"y":1900,"wires":[["6d1bb8c1.0a8278"]]},{"id":"fbb45a39.7ca4d8","type":"function","z":"9f6752b0.b55988","name":"","func":"msg.payload = msg.payload.PAC3;\nmsg.topic = \"Beladen\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1580,"y":1960,"wires":[[]]}]

If you have better ideas, please tell me

multixz · 8 April 2021 13:52

Hi Becker
Here is my solution. I would do it in one function like this:
Function with one output:

[{"id":"f44b690d.4c33b8","type":"function","z":"f6f2187d.f17ca8","name":"","func":"if (msg.payload.PAC3 >= 0){\n    msg = {\"payload\":msg.payload.PAC3,\"topic\":\"Entladen\"};\n    return msg;\n} else if (msg.payload.PAC3 < 0){\n    msg = {\"payload\":msg.payload.PAC3,\"topic\":\"Beladen\"};\n    return msg;\n} else {\n    return;\n}\n","outputs":1,"noerr":0,"initialize":"","finalize":"","x":640,"y":100,"wires":[["1320800b.1a02e"]]}]

Function with two outputs:

[{"id":"f44b690d.4c33b8","type":"function","z":"f6f2187d.f17ca8","name":"","func":"if (msg.payload.PAC3 >= 0){\n    msg = {\"payload\":msg.payload.PAC3,\"topic\":\"Entladen\"};\n    return [msg, null];\n} else if (msg.payload.PAC3 < 0){\n    msg = {\"payload\":msg.payload.PAC3,\"topic\":\"Beladen\"};\n    return [null, msg];\n} else {\n    return;\n}\n","outputs":2,"noerr":0,"initialize":"","finalize":"","x":640,"y":100,"wires":[["1320800b.1a02e"],["7fbc281d.69c638"]]}]```

E1cid · 8 April 2021 14:51

A simple ternary conditional to set topic should be fine.

msg.topic = msg.payload.PAC3 < 0 ? "Beladen" : "Entladen";
msg.payload = msg.payload.PAC3;
return msg;

[{"id":"f2cd37f3.77f548","type":"inject","z":"5a245aa1.510164","name":"2300","props":[{"p":"payload.PAC3","v":"2300","vt":"num"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":180,"y":3980,"wires":[["4d18ea91.fe6d24"]]},{"id":"f093cb4f.77554","type":"inject","z":"5a245aa1.510164","name":"-2300","props":[{"p":"payload.PAC3","v":"-2300","vt":"num"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":190,"y":4040,"wires":[["4d18ea91.fe6d24"]]},{"id":"4d18ea91.fe6d24","type":"function","z":"5a245aa1.510164","name":"","func":"msg.topic = msg.payload.PAC3 < 0 ? \"Beladen\" : \"Entladen\";\nmsg.payload = msg.payload.PAC3;\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":330,"y":4000,"wires":[["3b67977c.a53c08"]]},{"id":"3b67977c.a53c08","type":"debug","z":"5a245aa1.510164","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":610,"y":3800,"wires":[]}]

Becker · 8 April 2021 16:32

Hi, both solutions doesn´t work

my solution works:

[{"id":"b6efc276.3b37","type":"switch","z":"9f6752b0.b55988","name":"","property":"payload.PAC3","propertyType":"msg","rules":[{"t":"gte","v":"0","vt":"num"},{"t":"lt","v":"0","vt":"num"}],"checkall":"true","repair":false,"outputs":2,"x":1350,"y":1940,"wires":[["4d18ea91.fe6d24"],["fbb45a39.7ca4d8"]]},{"id":"6d1bb8c1.0a8278","type":"debug","z":"9f6752b0.b55988","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1870,"y":1820,"wires":[]},{"id":"4d18ea91.fe6d24","type":"function","z":"9f6752b0.b55988","name":"Entladen","func":"msg.payload = msg.payload.PAC3;\nmsg.topic = \"Entladen\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1480,"y":1920,"wires":[["b028ac79.76d8a"]]},{"id":"fbb45a39.7ca4d8","type":"function","z":"9f6752b0.b55988","name":"Beladen","func":"msg.payload = (msg.payload.PAC3 * -1);\nmsg.topic = \"Beladen\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1480,"y":1960,"wires":[["b028ac79.76d8a"]]},{"id":"e2b13662.528b18","type":"join","z":"9f6752b0.b55988","name":"","mode":"custom","build":"object","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":true,"timeout":"","count":"1","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":1870,"y":1880,"wires":[["6d1bb8c1.0a8278"]]},{"id":"b028ac79.76d8a","type":"calculate","z":"9f6752b0.b55988","name":"Durchschnitt pro Minute","pauseType":"timed","calculation":"average","timeout":"10","timeoutUnits":"seconds","rate":"10","x":1690,"y":1940,"wires":[["f01d2ea8.e59cb"]]},{"id":"f01d2ea8.e59cb","type":"function","z":"9f6752b0.b55988","name":"runden","func":"var temp = msg.payload\nmsg.payload = parseFloat(temp.toFixed(0));\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1880,"y":1940,"wires":[["e2b13662.528b18"]]}]

but there is one problem, the last value is always being stored in the object.

PAC3 is the Inverter output.
positive = unloading
negative = loading

never be both !

I need an object output with the correct value.
thats what is happening:

502 is the last value, and its being stored.
It must be set to "0" or delete.

E1cid · 8 April 2021 16:47

Both solutions work
here is proof using your supplied fow and my example , they both give exactly the same output.

as seen in image both flows give same output.

Your new flow example is different and includes a non standard contrib node, so I can not add it, as you failed to name it

So without knowing the mystery node and what it is calculating, I don't think anyones example will work for you.

Becker · 8 April 2021 16:52

sry, it is only "node-red-contrib-calculate" - but you can delete it and "runden", it doesn´t matter for the result.

E1cid · 8 April 2021 16:59

with out the calc node

[{"id":"f093cb4f.77554","type":"inject","z":"5a245aa1.510164","name":"-2300","props":[{"p":"payload.PAC3","v":"-2300","vt":"num"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":190,"y":4040,"wires":[["4d18ea91.fe6d24"]]},{"id":"4d18ea91.fe6d24","type":"function","z":"5a245aa1.510164","name":"","func":"msg.topic = msg.payload.PAC3 < 0 ? \"Beladen\" : \"Entladen\";\nmsg.payload = msg.payload.PAC3;\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":330,"y":4000,"wires":[["dc737e2d.6fbe4","60a9ce87.71931"]]},{"id":"f2cd37f3.77f548","type":"inject","z":"5a245aa1.510164","name":"2300","props":[{"p":"payload.PAC3","v":"2300","vt":"num"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":180,"y":3980,"wires":[["4d18ea91.fe6d24"]]},{"id":"dc737e2d.6fbe4","type":"debug","z":"5a245aa1.510164","name":"ternary","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":760,"y":4080,"wires":[]},{"id":"60a9ce87.71931","type":"function","z":"5a245aa1.510164","name":"runden","func":"var temp = msg.payload\nmsg.payload = {[msg.topic]: parseFloat(temp.toFixed(0))};\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":620,"y":4000,"wires":[["dc737e2d.6fbe4"]]}]

Becker · 8 April 2021 17:06

grafik
only error comes out

E1cid · 8 April 2021 17:09

Whats the flow and which function is causing the error, as you can see from my last post it works, so you must have change something or the input data

Becker · 8 April 2021 18:59

can we please focus on the problem: if the value PAC3 is switching between + and -, than the last output is beeing stored. I don't know how to get around that !

One of the new outputs ( "Entladen" or "Beladen" ) has to be zero.

PAC3 is from a buffer parser, the buffer parser is from Modbus:

{"topic":"PAC3","messageId":"606f5271f53dcc48e91efbd7","payload":507,"queueLengthByUnitId":{"unitId":3,"queueLength":0},"queueUnitId":3,"unitId":3,"modbusRequest":{"value":1617908337460,"unitid":"3","fc":4,"address":"30775","quantity":"2","messageId":"606f5271f53dcc48e91efbd7"},"responseBuffer":{"data":[0,507],"buffer":[0,0,1,251]},"_msgid":"bd027958.c0bdf8","originalPayload":[0,507],"specification":{"options":{"byteSwap":[],"resultType":"keyvalue","singleResult":true,"msgProperty":"payload","setTopic":true},"items":[{"type":"int32be","name":"PAC3","offset":0,"length":1,"offsetbit":0,"scale":"1","mask":"","id":0,"value":507}]},"values":[507],"objectResults":{"PAC3":{"type":"int32be","name":"PAC3","offset":0,"length":1,"offsetbit":0,"scale":"1","mask":"","id":0,"value":507}},"keyvalues":{"PAC3":507},"arrayResults":[{"type":"int32be","name":"PAC3","offset":0,"length":1,"offsetbit":0,"scale":"1","mask":"","id":0,"value":507}],"buffer":[0,0,1,251]}

E1cid · 8 April 2021 20:16

There is no msg.payload.PAC3 in that object msg.payload is a integer.

P.s. when did we not focus on the problem?

Becker · 8 April 2021 20:37

So what should I do ?

E1cid · 8 April 2021 20:41

If msg.payload in the object you posted is the value you require then change the function to use msg.payload.
in this example i have recreated the object you posted and fedd it into the altered function that targets msg.payload

[{"id":"79374974.a4c608","type":"inject","z":"5a245aa1.510164","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":120,"y":4140,"wires":[["cd76cbac.cb34"]]},{"id":"cd76cbac.cb34","type":"function","z":"5a245aa1.510164","name":"create object for testing","func":"msg = {\"topic\":\"PAC3\",\"messageId\":\"606f5271f53dcc48e91efbd7\",\"payload\":507,\"queueLengthByUnitId\":{\"unitId\":3,\"queueLength\":0},\"queueUnitId\":3,\"unitId\":3,\"modbusRequest\":{\"value\":1617908337460,\"unitid\":\"3\",\"fc\":4,\"address\":\"30775\",\"quantity\":\"2\",\"messageId\":\"606f5271f53dcc48e91efbd7\"},\"responseBuffer\":{\"data\":[0,507],\"buffer\":[0,0,1,251]},\"_msgid\":\"bd027958.c0bdf8\",\"originalPayload\":[0,507],\"specification\":{\"options\":{\"byteSwap\":[],\"resultType\":\"keyvalue\",\"singleResult\":true,\"msgProperty\":\"payload\",\"setTopic\":true},\"items\":[{\"type\":\"int32be\",\"name\":\"PAC3\",\"offset\":0,\"length\":1,\"offsetbit\":0,\"scale\":\"1\",\"mask\":\"\",\"id\":0,\"value\":507}]},\"values\":[507],\"objectResults\":{\"PAC3\":{\"type\":\"int32be\",\"name\":\"PAC3\",\"offset\":0,\"length\":1,\"offsetbit\":0,\"scale\":\"1\",\"mask\":\"\",\"id\":0,\"value\":507}},\"keyvalues\":{\"PAC3\":507},\"arrayResults\":[{\"type\":\"int32be\",\"name\":\"PAC3\",\"offset\":0,\"length\":1,\"offsetbit\":0,\"scale\":\"1\",\"mask\":\"\",\"id\":0,\"value\":507}],\"buffer\":[0,0,1,251]}\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":360,"y":4140,"wires":[["4d18ea91.fe6d24","dc737e2d.6fbe4"]]},{"id":"4d18ea91.fe6d24","type":"function","z":"5a245aa1.510164","name":"","func":"msg.topic = msg.payload < 0 ? \"Beladen\" : \"Entladen\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":330,"y":4000,"wires":[["dc737e2d.6fbe4","60a9ce87.71931"]]},{"id":"dc737e2d.6fbe4","type":"debug","z":"5a245aa1.510164","name":"ternary","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":700,"y":4080,"wires":[]},{"id":"60a9ce87.71931","type":"function","z":"5a245aa1.510164","name":"runden","func":"var temp = msg.payload\nmsg.payload = {[msg.topic]: parseFloat(temp.toFixed(0))};\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":620,"y":4000,"wires":[["dc737e2d.6fbe4"]]}]

Becker · 18 April 2021 15:05

Hi,
Please excuse me for not having tried it in so long.

your function works, it differentiates between loading and unloading.
but I need always (every 5s when modbus come in) two outputs:

value 0 or above = unloading with actual value & load = 0
value negative = loading with actual value *-1 & unloading = 0

I tried some, buth I don´t get it:

msg.topic = msg.payload.PAC3 < 0 ? "Entladen" : "Beladen";
var Be
var En
if (msg.topic == "Beladen") {
    Be = msg.payload.PAC3 * -1;
    En = null;
} else {
    Be = null;
    En = msg.payload.PAC3;
}
return msg;

or

var PAC3 = msg.payload;
var Be;
var En;
if(PAC3 < 0 ) {
    Be = (PAC3 * -1);
    En = null;
} else {
    En = PAC3;
    Be = null
}
return [Be,En];

I need every 5s (when modbus comes in) and object for example with:

Entladen = 0
Beladen = 1234

or

Entladen = 1111
Beladen = 0

or both 0

maybe @Steve-Mcl has an idea ?

Colin · 18 April 2021 15:50

Where do you need the outputs?

Steve-Mcl · 18 April 2021 18:23

A better solution might be...

msg.topic = msg.payload.PAC3 < 0 ? "Entladen" : "Beladen";
msg.payload = msg.payload.PAC3; //store value in payload

//if payload is < 0 then * by -1
if(msg.payload < 0 ) {
    msg.payload = (msg.payload * -1);
}

return msg;

As Colin said, it all depends on what you want to come out of the function.

ASSUMPTION: the value you want to check is in msg.payload.PAC3 and you want the result to come out in msg.payload;

Becker · 18 April 2021 19:35

I don´t get the basics of JS.
Every time I think I have understood, Node-Red shows me that I have not understood anything.

var msg1; 
var msg2;
var PAC3 = msg.payload;
var Bel;
var Ent;
if(PAC3 < 0 ) {
    Bel = (PAC3 * -1);
    Ent = null;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
} else {
    Ent = PAC3;
    Bel = null;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
}
return [msg1,msg2];

or

var msg1; 
var msg2;
var PAC3 = msg.payload.PAC3;
var Bel;
var Ent;
if(PAC3 < 0 ) {
    Bel = (PAC3 * -1);
    Ent = null;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
} else {
    Ent = PAC3;
    Bel = null;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
}
return [msg1,msg2];

both doesn´t work,
always get "TypeError: Cannot set property 'payload' of undefined" or just "undefined"

I just want to show these two values in my dashboard as:
Beladen = (+) ... W
Entladen = (+) ... W

one of both always has to be 0.

and furthermore I would like to write it as an object in Influx.

Becker · 18 April 2021 19:44

Now I connected the function directly to the buffer parser:

var PAC3 = msg.payload.PAC3;
var msg1 = {}; 
var msg2 = {};
var Bel;
var Ent;
if(PAC3 < 0 ) {
    Bel = (PAC3 * -1);
    Ent = 0;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
} else {
    Ent = PAC3;
    Bel = 0;
    msg1.payload = Bel;
    msg2.payload = Ent;
    msg1.topic = "Beladen";
    msg2.topic = "Entladen";
}
return [msg1,msg2];

Now I get:
grafik

better, but one is left

Steve-Mcl · 18 April 2021 19:45

To set a property of an object you must first make the variable an object

E.g...

var msg1 = {};
msg1.payload = "now it works";

You can return 2 messages as you are or 1 message with multiple properties (usually in the payload)

E.g...

msg.payload ={};
msg.payload.beladen = 123;
msg.payload.entladen = 456;
return msg;

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