once again RB, thank you 
I found this support thread about the Vision app for Homey:
Maybe I should have posted my question there instead?
Iโm new to Homey and the support forum, and on a steep learning curve 
However, reading through this thread, I could not see any unambiguous proof that the Vision app for Homey supports the Outdoor siren ZM1621-5?
Kind regards
Finn