dude, seriously. look on the linuxmce wiki under GSD (Generic Serial Device).. it provides a web-based interface for sending commands to any serial port based device... all of what I mention below is done via the web interface...
basically, you need to create a device template, that is a climate device (use the pull-downs to select the appropriate device type)..
at which point, you will be walked through a series of checkboxes etc to pick which commands you want to implement, and you'll be given boxes to enter commands to send down the serial port. You can check each command to make sure they work properly, and when you're ready, you can save the device template, and add the device to your system, again using the web based interface.. If it is possible to detect the device over the serial port (say, a specific sequence of commands etc), a plug-and-play script can be created to automatically detect the device as it is plugged into the serial port (this part is manual).