RS-232 in a MySensors RS485 network for GSM/SMS modem

[dzjr]

Friends of MySensors,

For some alarms I would like to use an SMS modem so that I can send a message to my phone even when the internet fails.

Now I have a Siemens MC35i GSM modem which I would like to use for this which can be controlled via RS232.

However, I have a wired MySensors RS485 network, and I was wondering if these two go together, considering you have a total of 3 serial connections (incl pin 0/1).

Is there a simple example in which, for example, when an incoming alarm telegram (from the MySensors network) sends a certain text string / SMS message?

Or maybe you have a much better solution for this.

Sending an SMS over the internet is not an option as I want to use this as a backup in case of an internet outage.
Last night it turned out that I also did not receive pushover messages due to a major power outage in the region.

I am very curious about your ideas.

Thanks for contributing ideas.

dzjr