Extend async RS232 devices beyond the 50 ft limitation using single-mode fiber cables at data rates up to 115.2 kbps and reach distances of 18.6 MI. (30KM). Serial extenders work well in factory automation, building automation, and process automation where PLC's with RS232 interfaces are used to control devices. The ability to extend the distance to their devices over single-mode fiber while also adding protection from electrical interference, which can be caused by large motors, which are prevalent in these environments, is very beneficial.