The Free Electron Laser in Hamburg (FLASH) is the firstlinac which is equipped with a MicroTCA.4 based low levelRF control system. Precise regulation of RF fields is essen-tial for stable and reproducible photon generation. FLASHbenefits from the performance increase using the new devel-opments like, accurate and precise field detection devices.Further enormous increase of processing capabilities allowfor more sophisticated controller applications which betterthe overall performance of the regulation
