Advantech ADAM-4520-EEProduct Attribute Attribute Value Series ADAM 4000 Series Overview Most industrial computer systems come with standard RS 232 serial ports. Though widely accepted, RS 232 has limited transmission speed, range, and networking capabilities. The RS 422 and RS 485 standards overcome these limitations by using differential voltage lines for data and control signals. The ADAM 4520 4522 converter lets you take advantage of RS 422 and RS 485 on systems