I was asking myself which are the bindings using serial communication and which one could I take as skeleton for a new binding (binding to control an alarm panel) ?
The DSC Alarm Binding might be a reasonable option. It’s got some stuff that can definitely be trimmed out, but it’s got the serial handling (since it deals with IT100’s over Serial, but Envisalink modules over Ethernet)
Take a moment to think about the protocol of your alarm panel. Is it ASCII and line-terminated? Is it wrapped in STX/ETX bytes? If so you can get Vera to wrap up a single packet into one call. If not you will have to use the “raw” protocol and build up your message one byte at a time. My Caddx alarm plugin is in this latter category.
Edit: I didn’t see that you were asking this in the OpenHAB subforum. My reply might not be as relevant as I thought.