Importing two payloads as variables and use them for calculation

[Lenaschitz]

hi guys,
I wanna import two different payloads (with two different topics) to a function node and use them to calculate someting. At the end the result should be send out as a payload again.
I get the two values from another flow, that´s working. If I replace the two variables with static values, the funtion node works. But not using the payloads. Any hints for a beginner?
Regards

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[jbudd]

Hi @Lenaschitz,

You are almost there but you need to use a join node so that the humidity and temperature are both available in a single message as msg.payload.humidityout and msg.payload.tempout.
A function node. like almost all nodes, only sees one message at a time.

Try this

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There are a couple of things about your function node too.

• You have return [msg1,msg3]; which implies that the node has two outputs. The Setup tab lets you control this.
• You calculate values for the objects es, ed, eln and td but you don't pass these on as message properties for use further along the wires

[Lenaschitz]

Hi jbudd,
many thanks for your reply, works now also with real data. Did read already a lot about the join node, but wasn´t aware to add a "2" for handling two messages instead of one.
And in the end I need td, but I was sure, were the issue comes from, so I wanted to see if both variables pass the function node.
Many thanks for your support.