UML modeling of the LINC-NIRVANA control software

LINC-NIRVANA is a Fizeau interferometer for the Large Binocular Telescope (LBT) doing imaging in the near infrared (J,H,K - band). Multi-conjugated adaptive optics is used to increase sky coverage and to get diffraction limited images over a 2 arcminute field of view. The control system consists of five independent loops, which are mediated through a master control. Due to the configuration, LINC-NIRVANA has no delay line like other interferometers. To remove residual atmospheric piston, the system must control both the primary and secondary mirrors, in addition to a third, dedicated piston mirror. This leads to a complex and interlocked control scheme and software. We will present parts of the instrument software design, which was developed in an object-oriented manner using UML. Several diagram types were used to structure the overall system and to evaluate the needs and interfaces of each sub-system to each other.