Serial binding and actions

Hi !
Already an openhab user with my knx home automation and completely satisfied (OH 1.7 on a raspberry),
now i would like to use openhab in a new project.
The goal is to interface multiples audio devices interconnected an a huge audio system (sources, matrix, power amplifier) with can be controlled by serial ports.
For this, i would like to use again OH on raspberry pi and usb to multiple serial ports interface.
So, i read all what i found about serial binding but i did not found any informations about how to use serial ports to send actions (send text by serial).
Does anybody can help me about how to do that ?
Thanks to bring help on the correct syntax in items definition for the states, but essentially on syntax to send actions in rules or scripts.
In case of success, i will probably write a little how-to for the example to the community because i love so much openhab that i would like to bring my little brick too !

Regards, JL.

Taking the example from the wiki page:

String AVR                "Surround System"    (Multimedia)    { serial="/dev/ttyS1@115200" } 

Just define the Item as a String. From rules you just sendCommand(“My string command”) and “My String command” (without the quotes) will be sent out.

AVR.sendCommand("My string command")

Yes, i have read this but it seem so simple that i was thinking i miss something…
Next to this will be to manage all commands, states and find the right UI…

or greenT seem to be cool too

Thank your for this reply !