Pozna, E.

Paper	Title	Page
THP087	Task Synchronization in the Observation Control Software for the ESO-VLT CRIRES Instrument	841
	E. Pozna, R. Schmutzer, A. J. Smette ESO, Santiago
	The ever increasing pressure for both high spectral and high angular resolution spectrograph imposes an increasing complexity on astronomical instrument control software, now a critical component in the instrument design. To achieve the accuracy required to maintain the image of the target within its 0.2 arcsec entrance slit, the Observation Control software(OS) for the ESO-VLT CRIRES instrument must take into account a number of optical phenomena (differential atmospheric refraction, distortion, etc.), some of them time dependent, even when observing an object moving at a rate different from the object used for auto-guiding. Five internal software control loops adjust the position of mechanical devices and/or the telescope on top of the OS standard functionalities (e.g. monitoring, exposure handling). Besides internal activities, the OS must promptly reply to sequential commands as well as simultaneous interruptions/adjustments from operator via GUI interface. The required advanced synchronization mechanisms are implemented as an extension to the OS framework (a tool collecting the general features of all instrument OS) while allowing for maintainability and future generalization.
	Poster
THP104	Exposure Synchronization in the Observation Control Software Framework at ESO	1
	E. Pozna ESO, Garching bei Muenchen
	The Observation Software (OS) of astronomical instruments, which lie directly beneath the instructions of astronomers, carrying out exposures and calibrations is the supervisor of the multi-process and multi-layer instrument software package. The main responsibility of the OS is the synchronization of the subsystems (detectors and groups of mechanical devices) and the telescope during exposures. The complexity of new instruments, their performance requirements, increasing image file size and file numbers increases the complexity of the OS synchronization required for the optimized exposure sequence on multiple detectors. At ESO a software framework Base Observation Software Stub (BOSS) takes care of the common functionalities of all OS of various instruments at the various sites VLT, VLTI, La Silla and Vista. While for numerous instruments this framework satisfies all requirements (configuration, monitoring, exposure image and error handling) for others it ensures the plug in of instrument specific properties using design patterns.