The MAORY ICS software architecture

The Multi Conjugate Adaptive Optics RelaY (MAORY) for ESO’s Extremely Large Telescope (ELT) is an adaptive optics module offering multi-conjugate (MCAO) and single-conjugate (SCAO) compensation modes. In MCAO, it relies on the use of up to six Laser Guide Stars (LGS) and three Natural Guide Stars (NGS) for atmospheric turbulence sensing and multiple mirrors for correction, providing high Strehl and high sky coverage. In SCAO mode, a single natural source is used as reference, providing better correction but in a smaller field. MAORY will be installed at the Nasmyth focus of the ELT. It will feed the MICADO first-light diffraction limited imager and a future second instrument. MAORY is being built by a Consortium composed by INAF in Italy and IPAG in France and is currently approaching end of phase B. In this paper we describe the preliminary design of the MAORY Instrument Control System Software (ICS SW). We start with an overview of the MAORY module and then describe the general architecture of the MAORY control network and software. We then describe the main software components, with particular emphasis to those managing the NGS and LGS wavefront sensors functions and the AO off-load and secondary loops, and the main interfaces to subsystems and external systems. We then conclude with a description of the software engineering practices adopted for the development of MAORY ICS SW.