ktp02

I have 2 wires siren I would like to add to VTH2421FW. I did the following wiring: COM ➡️ DC +12V NO ➡️ Siren DC -12V ➡️ Siren However, if door is open for certain time, internal beep on VTH is triggered and siren is not working. Any advice if this setup is correct? Is it possible to allow...