I have connected one reed switch as per wiki example and it works perfectly:
I'm a bit confused on how to connect another reed switch to digital isolated input. I don't have another external power source to use, should I connect to the module power supply? I tried using one of the Open collector output, but it didn't seem to work.
I would be grateful if you explain to me in more detail what you want to connect?
Perhaps this information will help you.
Kind regards, Igor/