door sensor set up

Hi I am new to the forum and I am looking for help in relation to setting up a door sensor to be monitored in that if the door is open for more than 20 seconds it will notify the homeowner by activating a sounder or siren connected via a module

Any ideas how i can set this up ?

What door sensor are you using? Does it report back to the controller (Vera) on both opens and closes? If so, you could write some Lua script to do it. If you want to give that a try and need help figuring out the logic, post back and I can provide some guidance.