Polar Ir Interface For Rs232 Serial Port

Polar Ir Interface For Rs232 Serial Port Serial Ports And

While multi-drop work-arounds have been devised, they have limitations in speed and compatibility.

It formally defines signals connecting between a DTE ( data terminal equipment ) such as a computer terminal, 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.

Polar Ir Interface For Rs232 Serial Port Serial Ports And

The RS-232 standard had been commonly used in computer serial ports and is still widely used in industrial communication devices.

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.

In modern personal computers, USB has displaced RS-232 from most of its peripheral interface roles.

Few computers come equipped with RS-232 ports, so one must use either an external USB-to-RS-232 converter or an internal expansion card with one or more serial ports to connect to RS-232 peripherals.

Nevertheless, thanks to their simplicity and past ubiquity, RS-232 interfaces are still usedparticularly in industrial machines, networking equipment, and scientific instruments where a short-range, point-to-point, low-speed wired data connection is fully adequate.

The character format and transmission bit rate are set by the serial port hardware, typically a UART, which may also contain circuits to convert the internal logic levels to RS-232 compatible signal levels.

The standard does not define bit rates for transmission, except that it says it is intended for bit rates lower than 20,000 bits per second.

The resulting common problems were non-standard pin assignment of circuits on connectors, and incorrect or missing control signals.

The lack of adherence to the standards produced a thriving industry of breakout boxes, patch boxes, test equipment, books, and other aids for the connection of disparate equipment.

A common deviation from the standard was to drive the signals at a reduced voltage.

Some manufacturers therefore built transmitters that supplied 5 V and 5 V and labeled them as RS-232 compatible.

For many years, an RS-232-compatible port was a standard feature for serial communications, such as modem connections, on many computers (with the computer acting as the DTE).

In personal computer peripherals, it has largely been supplanted by other interface standards, such as USB.

RS-232 is still used to connect older designs of peripherals, industrial equipment (such as PLCs ), console ports, and special purpose equipment.

The standard continued to be revised and updated by the Electronic Industries Association and since 1988 by the Telecommunications Industry Association (TIA).

Revision C was issued in a document dated August 1969.

The current revision is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997.

The voltage range was extended to 25 volts, and the circuit capacitance limit was expressly stated as 2500 pF.

Revision E of EIA-232 introduced a new, smaller, standard D-shell 26-pin Alt A connector, and made other changes to improve compatibility with CCITT standards V.24, V.28 and ISO 2110.

The voltage swing requirement also limits the upper speed of a compatible interface.