Serial Communication have been around for many years and a wide range of equipment communicates on either a RS232, RS422 or RS485 communication protocol. Over the years, dozens of protocols have been crafted to meet particular needs of Industrial Automation systems PLC Technologies has developed the most extensive line of RS232, RS422 or RS485 conversion and isolation products on the market.
A serial port sends and receives data one bit at a time over one wire. While it takes eight times as long to transfer each byte of data this way, only a few wires are required. In fact, two-way (full duplex) communications is possible with only three separate wires - one to send, one to receive, and a common signal ground wire.
Mark Twain once said, “the reports of my death have been greatly exaggerated.” Pundits have been predicting the death of RS232, RS422 or RS485 communications for years – but billions of dollars of perfectly good equipment continues to perform useful service every day. And not just legacy equipment — lots of new devices, from sensors to scales still use this interface as the main communication protocol.