The Upgraded Telescope Control System Performance For The Canada-France-Hawaii Telescope

The Canada-France-Hawaii Telescope (CFHT) completed the first phase of its TCS upgrade in early 2015. Prior to this effort, the previous version of CFHTs TCS was largely unmodified since it began operation in 1979 and had begun to exhibit reliability and maintainability issues entering its third decade of operation. The first phase consisted of replacing the custom-built servo control hardware built by the Canadian Marconi Company with an off-the-shelf Delta Tau Systems Power PMAC and replacing the absolute and incremental encoders with modern equivalents. Adapting the motion control algorithms used within the Power PMAC for real-time control of the telescope on the sky posed unique challenges. This work briefly summarizes the design for the upgraded TCS at CFHT, describes the solutions that adapted the traditional use of the Power PMAC for use at CFHT, and discusses the improved performance of CFHTs new TCS in terms of decreased time to target and tracking error.