The RS-232 Serial Connection
RS-232 (or Recommended Standard 232) is a standard computer communications system that’s more commonly known as a serial connection. You’ve probably used an RS-232 connector if you’ve ever connected a modem to an older PC (whether or not you knew what it was called).
You may encounter the RS-232 serial connection when you are setting up your home theater. This is particularly true if you are hooking your home theater into a whole-home network or connecting PCs and other computer-like devices (such as PVRs and MP3 servers) into your home theater.
Here are some details on the RS-232 serial connection:
Until the advent of the USB system, RS-232 was considered the standard connection for modems, handheld computer cradles, and many other PC peripheral devices.
In the home theater world, RS-232 is not used for carrying audio and video. It is, however, often used for connecting A/V components to automation and control systems (such as touchpads and controllers used in a whole-home control system by Crestron Electronics).
You can also find RS-232 ports on the back of many advanced A/V receivers, where they can be used to connect the receiver to a PC for upgrading the software system within the receiver.