For some reasons Agilent decided to use obsoleted PL-2303HX chip in its U1173A, USB to IR cable. In practice this means that you won't be able to use this cable on Windows 8 and higher.
This board uses FT232RL chip and it is direct replacement for one used in USB to IR cable. Prolific drivers support Windows (98 to 8), Linux, and OS X. Since chip is very common there is probably no system that cannot be tweaked into working with it (even Android).
Gerbers, parts and other details can be found at GitHub.
