I have 12-zone interface module (interface kit) that notifies on app when there is motion signal, but I haven’t programmed my old security system to get order from the smart alarm system (due to not knowing the installer code and not wanting to reset the whole system). Then, is it possible to connect the siren wires directly to the alarm panel to get an order through wifi to sound the alarm?
Not the answer to your question but something I faced and did.
When I connected alarm from Konnected interface kit directly to Alarm zone on my old system - my old system just goes into Siren mode as soon as I turn on power to my Konnected interfcae kit. Tried many things but could not make it work Then I was told by Konnected support to reset the Konnected interface and try again which I cannot do unless I have time and patience to do all programming again.
I connected a completely separate siren to Konnected and that works. So, not using the existing siren.
Now, coming to your question: It is possible to connect Konnected to old alarm because Alarm from konnected will provide power to old siren for it to make sound but you might face a problem like me where Siren just goes off as soon as you power on Konnected interface.
I have installer code and have connected old system and Konnected - like keyswitch etc but still I had to go for new siren ($15-20 on amazon) because of problem I stated above. Thanks