The RS-485 standard was published in 1983 and is substantially similar to the earlier RS-422 standard. What is the difference between RS232 and RS485? RS-422 is also found on professional video broadcasting equipment.

RS-422 was used with a smaller 8-pin mini-DIN connector on early Apple Macintosh computers to connect to AppleTalk networks and various peripherals. It specified the same DB25 connector as the original RS-232 standard. It used lower voltages and differential signaling to support faster data transmission, longer cable lengths and reduced RF/EMI noise. Introduced in 1975, the RS-422 standard was intended as a replacement for RS-232C. What is the difference between RS232 and RS422? Rather than replace these devices (if replacement is even possible), an inexpensive way to extend their life is to use a serial to USB adapter to connect to a modern laptop's USB-A or USB-C port. It is still common on legacy devices that use serial communications for data capture, configuration and control. By specifying the voltage, signaling, pin wiring and control data between a host device and a peripheral, the RS-232 standard ensured that devices from different manufacturers could communicate with each other.Ī serial port was standard on personal computers until the late 1990s, when it was mostly replaced by the Universal Serial Bus (USB). RS-232 is a simple serial communication standard in which one bit of data is transmitted at a time over a serial cable at the relatively slow rate of up to 20K bits/second and distances up to 50-ft. It was later adopted by the personal computer industry so PCs could connect to modems, peripherals and data acquisition devices such as lab test equipment, GPS receivers and point of sale terminals. RS-232 (originally called Recommended Standard 232 but shortened to RS232) was developed by the Electronic Industry Association (EIA) in the 1960s for the exchange of data between DTE (Data Terminal Equipment) and DCE (Data Communication Equipment).

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