MedAustron is an accelerator facility for proton-, ion-therapy and research which is going to be built in Austria. The facility uses proton beams for scientific applications with kinetic energies up to 800 MeV and therefore, neutron dominated fields up to several hundred MeV can be expected behind shielding. During the operation of the accelera-tor dose levels have to be monitored with appropriate equipment, such as the WENDI-II REM counter a , to prove that the dose does not exceed the legal limits inside accessible areas. In order to demonstrate the appropriateness of the WENDI II, measurements at the Research Center for Nuclear Physics (RCNP) facility at Osaka University of Japan were conducted in quasi monoenergetic neutron beams of 246 MeV and 389 MeV. In the literature the WENDI-II de-tector was already characterized in mixed fields at CERN as well as quasi monoenergetic fields up to 173 MeV at the T. Svedberg Laboratory. This paper provides a characterization for neutron fields at higher energies and compares the measurements with FLUKA simulations. Additionally, a series of measurements with iron shielding of different di-mensions was conducted as the WENDI-II will be utilized behind thick shielding at MedAustron.