Here I have an event with Homeseer automation software that gets triggered and sends a message to my cellular phone over via the internet.
There are three phone variables that can be looked at with 3rd party software: (there is a phone and just a trouble variable - trouble variable can be anything).
The below is relating to Homeseer 2 HAI plugin which is a serial connection. The "trouble" variable is instant to whatever the issue is (battery, AC power, phone, freeze, water, etc).
1 - off and on hook
2 - time of off and on hook
3 - phone dead line
That said though too your CS monitoring should auto message you if you phone line goes down.
It could also be the HAI (if that is what you are using) hardware is failing or you have a loose wire some place or just a poor cellular signal?
I utilize copper still as primary although that will probably be going away soon.
That said the root cause of your issue might just be a poor cellular signal.
This is something that should be fixed as you do not want this to happen at an inopportune time.
Being messaged if you phone line goes down is good but is just a band aid to your root issue.
You can if you want just move the cellular box with the antenna to a higher point in your home for a better signal.
