Subtract 2 functions

[Bos1982]

So I’m new to this forum and rather new to Node-Red.
I’m struggling with the following..

I would likely subtract 2 functions. I have come quite far but now really get stuck.

The whole idea is to “ Input a function” and subtract a 2nd function..
This second function has now a “ random” input which I will replace by an input node once I get the subtract to work..

[{"id":"24b0f66.0f9d10a","type":"tab","label":"Flow 7","disabled":false,"info":""},{"id":"75f6918.86e68f","type":"inject","z":"24b0f66.0f9d10a","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"1","payloadType":"num","x":897.511962890625,"y":474.2009582519531,"wires":[["9a61246.54797d8"]]},{"id":"585bb5be.c60cfc","type":"inject","z":"24b0f66.0f9d10a","name":"","props":[{"p":"topic","vt":"str"},{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"Control","payload":"Open","payloadType":"str","x":917.511962890625,"y":554.2009582519531,"wires":[["6f428f17.9d8688"]]},{"id":"cd154dbb.c93a3","type":"inject","z":"24b0f66.0f9d10a","name":"","props":[{"p":"topic","vt":"str"},{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"Control","payload":"Close","payloadType":"str","x":937.511962890625,"y":594.2009582519531,"wires":[["6f428f17.9d8688"]]},{"id":"5525ef64.e97ec","type":"inject","z":"24b0f66.0f9d10a","name":"","props":[{"p":"payload"}],"repeat":"0.5","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"1","payloadType":"num","x":897.511962890625,"y":634.2009582519531,"wires":[["6f428f17.9d8688"]]},{"id":"6f428f17.9d8688","type":"gate","z":"24b0f66.0f9d10a","name":"","controlTopic":"control","defaultState":"closed","openCmd":"open","closeCmd":"close","toggleCmd":"toggle","defaultCmd":"default","statusCmd":"status","persist":false,"x":1197.511962890625,"y":654.2009582519531,"wires":[["17a6e604.a0ccf2"]]},{"id":"9a61246.54797d8","type":"random","z":"24b0f66.0f9d10a","name":"","low":1,"high":"100","inte":"true","property":"Payload","x":1297.511962890625,"y":574.2009582519531,"wires":[["3c38f27d.68d4d6"]]},{"id":"3c38f27d.68d4d6","type":"function","z":"24b0f66.0f9d10a","name":"T1","func":"msg.topic=\"T1\";\nmsg.payload =(msg.payload)\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1477.511962890625,"y":574.2009582519531,"wires":[["d4f07c2b.1956c8"]]},{"id":"17a6e604.a0ccf2","type":"counter","z":"24b0f66.0f9d10a","name":"","init":"0","step":"1","lower":null,"upper":"25","mode":"increment","outputs":2,"x":1397.511962890625,"y":674.2009582519531,"wires":[["6c5b8392.5c1f2c"],[]]},{"id":"fb5baefb.f5018","type":"function","z":"24b0f66.0f9d10a","name":"Reset Counter","func":"msg.reset=msg.payload\nreturn msg;","outputs":1,"noerr":0,"x":1257.511962890625,"y":774.2009582519531,"wires":[["17a6e604.a0ccf2"]]},{"id":"e514d501.97aee","type":"inject","z":"24b0f66.0f9d10a","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"0","payloadType":"str","x":1077.511962890625,"y":814.2009582519531,"wires":[["fb5baefb.f5018"]]},{"id":"6c5b8392.5c1f2c","type":"function","z":"24b0f66.0f9d10a","name":"T2","func":"msg.topic=\"T2\";\nmsg.payload = (msg.payload)\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1637.511962890625,"y":814.2009582519531,"wires":[["d4f07c2b.1956c8"]]},{"id":"d4f07c2b.1956c8","type":"join","z":"24b0f66.0f9d10a","name":"","mode":"custom","build":"object","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":1897.511962890625,"y":774.2009582519531,"wires":[["47026e9a.c4fcb8"]]},{"id":"47026e9a.c4fcb8","type":"function","z":"24b0f66.0f9d10a","name":"Subtraction","func":"val1 = msg.T2\nval2 = msg.T1\n\nmsg.payload = val1 - val2;\nmsg.topic = \"Number\";\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1897.511962890625,"y":594.2009582519531,"wires":[["e65c48dc.c27b18"]]},{"id":"e65c48dc.c27b18","type":"debug","z":"24b0f66.0f9d10a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":2077.511962890625,"y":654.2009582519531,"wires":[]}]

What am I doing wrong? I think it is in the subtract or join node..

[Steve-Mcl]

Hi, you flow cannot be imported it is important to surround your code with three backticks
```
code here
```

You can edit and correct your post by clicking the pencil icon.

See this post for more details - How to share code or flow json

[E1cid]

As far as i can tell from you posted code, which is corrupt due to not following the forum guidelines.

Your join node has no limits, i.e there is no count or time limit, so your messages never get passed.

[Steve-Mcl]

CLUE: in the last function, you access msg.T1 - this is wrong. Read this : Working with messages : Node-RED to understand how to avoid this.

Pay particular attention to the bit about hovering over the debug item and the "copy path" button - this will help you fix your issue.

[Bos1982]

Better like this?

[Steve-Mcl]

no, better now i have edited it.