No, it won't work:
- Support for external clocking is missing (it is not mentioned in the Prolific PL2303 technical information and none of its pins can be used for that purpose), so it's not compatible with the Emulator-II
- The DB25-to-DB9 wiring of the cable is not compatible with the Emulator-II
- This USB-RS422 device is not supported by EMXP
Only an EmuSer and a custom built cable will work with the Emulator-II.
You can contact Freddy (member of this forum) and ask if he's still building and selling EmuSers and cables.
Check this thread:
http://eiiiforum.com/index.php?topic=2071.45