What is RS-422?

RS-422 is a telecommunications standard for binary serial communication between devices. The protocol or specifications should be followed to allow two devices that implement this standard to talk to each other. The RS-422 is an updated version of the original serial protocol known as the RS-232. One device will be known as a data terminal device (DTE) and the other device is known as data communication equipment (DCE). For example, in a typical example of a serial connection between a computer and a printer, the DTE computer is a DTE and the printer is a DCE device.

RS is a recommended standard that allows manufacturers to interpret the standard, although the differences are usually small. However, to avoid problems, the standard was formalized by the Electronic Industries Alliance alliance and the International Telecommunications Industry Association and is now referred to as the EIA/TIA-422 standard.

RS-422 is a balanced four-wire system. A signal sent from the DTE device is transmitted to the afterDip control via two wires and a signal sent from the DEC device to DTE is transferred by two more wires. The signals on each pair of conductors are a mirror opposite each other, ie the date "1" is transmitted as a reference of 2 volts on one wire and on the other wire minus 2 volt. If you want to send the date "0", the link to minus 2 volt is transmitted by one wire and link to 2 volts to the other wire. This is the opposite of what happened for transmission and \ '1 \' date. This balanced differential approach allows much longer distances between DCE devices and DTE devices than the previous 3 RS-232 wire standards.

Standard states of RS-422, which must be used signaling voltages, what connectors should be used, what pins on those connected to each function and also recommends maximum distances for which this technology can be used reliably.

Standards are very important in industry because it allows consumer to buy a computer (deviceDTE) from one manufacturer and printer (Dce of the equipment) from another manufacturer and expect to work together. Standards are also constantly changing because there are restrictions and new solutions are being proposed. If changes become too drastic, a new standard is developing. In this way, the standard RS-422 has evolved from the original RS-232 standard and in many cases. The RS-422 has now been replaced by the RS-485 standard, which adds additional features to the RS-422 standard.

For more information about this standard visit to the Electronic Industries Alliance or Telecommunications Association.