MAVIS Instrument Control Software: toward the preliminary design

The MCAO Assisted Visible Imager and Spectrograph (MAVIS) is a new instrument being built for the ESO's Very Large Telescope (VLT). It will operate at the Nasmyth focus of "UT4" telescope and it is composed of two main parts: a Multi Conjugate Adaptive Optics (MCAO) module and two post focal scientific channels, an imager and an integral field spectrograph, both operating in the visible spectrum. The project is approaching the final steps of the preliminary design phase and it is expected to have the first light in 2027. We present the status of the Instrument Control Software (ICSS). In particular, we focus on the software architecture and the interaction between ICSS and real-time computer (RTC), telescope control system (TCS) and VLT Laser Guide Stars Facility (4LGSF). Besides the complexity of the instrument, we present a software architecture that is simple and still maintains modularity, guaranteeing the overall functionality of the instrument.