Design of telescope and instrument control and interface software at the South African Astronomical Observatory: building blocks of the intelligent observatory

We present an overview of the Intelligent Observatory (IO) and the architecture used at the South African Astronomical Observatory (SAAO) to develop instrument and telescope control and monitoring software. The IO aims to link and coordinate the usage of the SAAO telescopes and instruments for optimal efficiency. This will entail a Central Control System (CCS) selecting appropriate instruments and telescopes and controlling observations on these. This requires interoperable instrument and telescope control software. The SAAO software architecture is flexible, allows multiple user interfaces, and supports remote control and monitoring of both telescope and instrument through a web browser. Furthermore, the architecture allows an external agent (such as the IO CCS) simultaneous control of both instruments and telescopes.