RS-232
| EIA-232 Standard | |
|---|---|
| Interconnection of Data Terminal Equipment with a Communications Channel | |
Data circuit-terminating equipment (DCE) and data terminal equipment (DTE) network | |
| Status | Active |
| Year started | 1960 |
| First published | 1 May 1960 |
| Latest version | TIA-232-F 1 October 1997 |
| Organization | Electronic Industries Association |
| Series | EIA Recommended Standards |
| Related standards | TIA/EIA-422 ITU-T/CCITT V.24 ITU-T/CCITT V.28 |
| Successor | TIA/EIA-422 |
| Domain | Telecommunications, Computing, Electronics |
| RS-232 protocol | |
|---|---|
| Governing body | Electronic Industries Association |
| Standard | EIA-232 |
| Protocol information | |
| Network topology | Point-to-point, unidirectional point-to-point |
| Maximum speed | 20 kbit/s |
| Mode of operation | Serial |
| Voltage | 3 to 15 Vpp (maximum voltage for each line) |
| Mark(1) | Negative voltage |
| Space(0) | Positive voltage |
| Available signals | DTR, DCD, DSR, RI, RTS, RTR, CTS, TxD, RxD, GND, PG |
| Connector types | DB-25 connector |
In telecommunications, RS-232 or Recommended Standard 232 is a standard introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a DTE (data terminal equipment) such as a computer terminal or PC, and a DCE (data circuit-terminating equipment or data communication equipment), such as a modem. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. The current version of the standard is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997.
The RS-232 standard is commonly used with serial ports and serial cables. It is widely used in industrial communication devices.
A serial port complying with the RS-232 standard was once a standard feature of many types of computers. Personal computers used them for connections not only to modems, but also to printers, computer mice, data storage, uninterruptible power supplies, and other peripheral devices.
Compared with later interfaces such as RS-422, RS-485 and Ethernet, RS-232 has lower transmission speed, shorter maximum cable length, larger voltage swing, larger standard connectors, no multipoint capability and limited multidrop capability. In modern personal computers, USB has displaced RS-232 from most of its peripheral interface roles. Thanks to their simplicity and past ubiquity, however, RS-232 interfaces are still used—particularly in industrial CNC machines, networking equipment and scientific instruments where a short-range, point-to-point, low-speed wired data connection is fully adequate.