The Transio A52 and A53 are smart RS-232 to RS-422/485 bi-directional converters that come with all of the great technical specs that Moxa is known for. This includes data direction control built into the hardware for both the RS-422 and RS-485 interfaces, LED indicators for power and signal states, and surge protection and isolation protection. The last two features take care of some of the major problems faced by serial communication connections in industrial environments.