Using Serial/RS-232 can be a very reliable way to communicate with A/V equipment that hasn’t been modernized to support direct IP control. Some users even prefer Serial connections regardless. Roomie Remote provides Serial codes for a large set of tested devices listed here.
It is possible for advanced users to add additional commands manually. See this FAQ item for more information on adding device code sets for custom devices.
For Serial support, the supported serial adapters with appropriate Serial Cable should be used. Note that there is a special version of the cable for Samsung EX-Link and Sony TV control with a 3.5mm end.
A very important issue with Serial connections is the wiring of the cable. There are generally two major ways to wire a Serial cable: straight through and null modem. These cables are not compatible with each other and you must check your target device to make sure it is setup correctly. This is configured on the adapter’s settings web page under the “Crossover” setting.
Serial cables should be limited to 10 feet based on the electrical design of RS-232. Using a serial adapter is a great way to send a serial connection to distant locations by placing the adapter at the location rather than trying to create a serial cable that is too long.