USB Alternative
Serial Ports
RS-232 serial ports are a legacy point-to-point interface still used for network consoles, industrial equipment, instrumentation, and other specialized hardware.
Overview · Comparison to USB · Use cases · Articles
Related: Parallel Ports · IrDA · PS/2
Serial port overview
Review RS-232 serial ports as point-to-point communication interfaces, including common PC connectors, device types, signaling role, and continued use in industrial and technical systems.
| Primary purpose | Point-to-point serial communication |
|---|---|
| Common PC connector | DE-9 |
| Typical standard | RS-232 / ANSI/TIA-232 family |
| Typical devices | Modems, terminals, network consoles, industrial controllers, and instrumentation |
| General-purpose peripheral bus | No |
| Modern bridge | USB-to-serial adapters commonly add serial connectivity to computers without a native port |
| Current status | Legacy on consumer PCs but still common in specialized technical equipment |
Sources: TIA standards report covering ANSI/TIA-232 and Intel workstation serial-port documentation.
Serial port comparison to USB
Compare RS-232 serial ports with USB for point-to-point communication, peripheral range, connectors, hot plugging, adapters, and support for legacy industrial equipment.
| Factor | Serial port | USB |
|---|---|---|
| Primary role | Simple point-to-point serial communication | General-purpose host-to-device peripheral bus |
| Typical devices | Consoles, modems, controllers, instrumentation, and industrial equipment | Storage, input devices, audio, cameras, printers, networking adapters, and many more peripherals |
| Connector | DE-9 is common on PCs, with other serial connectors also used | Multiple USB connector families including USB-A and USB-C |
| Hot plugging | Depends on equipment and implementation rather than a modern plug-and-play model | Designed for plug-and-play peripheral connection |
| USB relationship | Legacy serial devices can remain useful through compatible USB-to-serial adapters | Provides the modern host-side connection for many serial adapters |
| Best fit | Existing serial consoles, industrial controls, and specialized equipment | Mainstream modern peripherals and general computer connectivity |
Sources: TIA standards report covering ANSI/TIA-232 and USB-IF USB4.
Serial port use cases
See where serial ports remain useful for network consoles, industrial controllers, instrumentation, legacy peripherals, and embedded equipment, and when USB is more practical.
| Use case | Why serial fits | Better modern option |
|---|---|---|
| Network console access | Many routers, switches, and appliances retain serial console workflows | USB-to-serial adapter when the computer lacks a native port |
| Industrial controllers | Long-lived equipment may depend on established RS-232 communication | Keep serial where required; migrate only when the equipment supports a newer interface |
| Instrumentation | Serial links remain common in measurement and laboratory equipment | USB-to-serial adapter or native USB instrument interface where supported |
| Legacy modem or terminal | Older hardware may require a native serial protocol | USB-to-serial bridge for modern computers |
| New consumer peripheral | Serial is rarely the practical choice | USB is generally preferable |
Serial port articles
Browse guides about USB-to-serial adapters, legacy equipment, drivers, troubleshooting, and connecting modern computers to serial devices.
