The ADAM-5091 is equipped with four RS-232 ports, which makes it especially suitable for bi-direction communication. It can simultaneously read data from other third-party devices such as modem, Bar Code reader, and PLCs as long as these devices are equipped with a RS-232 interface. Furthermore, the ADAM-5091 is fully integrated with the ADAM-4000/5000 series, and transmits data to each other through the RS-232 port.