Update one channel from another

[JohannesR]

Hi i am sorry for the many questions, but i am a newbie and I don't really get everything well ;)

I have one Channel that is a switch. With this switch i make a request on a serial device. That works fine now! I get an answer and i am able to interpret it. But now i want to use the Numbers(double) i got from the Answer for updating the other Channels. Because the other channels are Numbers for monitoring. So how can i link these two(or more) Channels? That https://www.eclipse.org/smarthome/documentation/development/bindings/thing-handler.html didn't help me. Is there a binding i can use as example? Or can someone explain it step by step?

Another question is, is it possible to edit the label of the Channel from the Handler?

Because sometimes i get temperature values and sometimes sun-emission values (depends on the device configuration) and i would like to have variable labels for the channels. :)

Thanks for the help!