Dimensioning the MAORY real time computer

The MAORY system is the Multi-Adaptive Optics module for the European Extremely Large Telescope first light. MAORY should provide high and homogeneous image quality over the MICADO Field of View (about 1 arcmin diameter) and still an acceptable correction up to the 3 arcmin technical Field of View. The baseline of MAORY is therefore to rely upon the use of multiple Laser Guide Stars (6), multiple Natural Guide Stars (3) and multiple Deformable Mirrors correction. The Real-Time Computer is a key sub-system of MAORY. It must collect the measurements from various sensing devices and drive thousands of actuators. Many correction loops are foreseen with different update rates. The main requirements concerning the system dimensioning and Real-Rime performance depend on the sensors and on the actuators interface and on the Real-Time Data Processing. In this paper we give a preliminary description of the MAORY Real-Time Control system functional requirements derived from the system baseline at the beginning of the instrument Phase B.