Your TV's RS-232 Serial Port Can Do A Lot More Than You Probably Realized
The RS-232, or Recommended Standard 232, is a serial communication protocol introduced in 1960 by the now-defunct Electronic Industries Association (EIA). If you're of a certain age and grew up with the pre-USB computers in the 1990s, then this nine-pin port –- simply known as a serial port to many –- will be familiar to you. These serial ports were once widely used to connect computers to peripherals such as mice, printers, and modems, and to connect two PCs directly for large file transfers.
In the modern era of computing, RS-232 has been superseded by USB and Ethernet, and has long since become a legacy port on computers –- but is still surprisingly common in other industries. Even with its limitations, RS-232 has a longstanding reputation of being both reliable and robust in terms of low-speed, serial data transmission. RS-232 is commonly used in CNC machine integration, programmable logic controllers (PLCs), point of sale (POS) systems, medical equipment, or for any application that may rely on legacy equipment. You'll even find an RS-232 port on certain models of TVs, and it can do a lot more than you probably realize.
What an RS-232 serial port on a TV can do
Most modern TVs, especially non-commercial and mid-range models, will make use of infrared (IR) and IP control via your local network for TV commands and control. However, on commercial TVs and high-end consumer models, it's not uncommon to find an RS-232 port alongside the usual crop of connections. The RS-232 port on TVs is widely used for troubleshooting issues with the TV, and can also be used to flash the TV's firmware or for other updates.
The RS-232 port can also be used in commercial environments for digital signage –- retail stores, medical offices, restaurants, or many other places can remotely control what's on multiple TVs by having them connected to a central source, likely through an HDMI/serial matrix switch, via RS-232. In a commercial setting, this is ideal because RS-232 is not cost-prohibitive to scale or implement.
Home automation and AV integration also use RS-232 to connect multiple TVs to a single source. Other types of AV devices like Blu-ray players and projectors can also include an RS-232 port so they can be integrated into an RS-232-controlled system. RS-232 connectivity can also be used to control devices through macro pads, PCs, tablets, and can be used with home automation control platforms –- Crestron, Extron, Control4, and others all have some level of support for RS-232. There are several types of serial adapters to include RS-232 functionality, like USB to serial adapters or RS-232 to Bluetooth converters.