Modernization Of The 1-Meter Swope And 2.5-Meter Du Pont Telescopes At Las Campanas Observatory

The Observatories of the Carnegie Institution for Science have operated the 1 and 2.5-meter telescopes since the early 1970s with only minor changes to the original control systems. We discuss the replacement of the original 4004 micro-processor-based telescope control system with modern high-speed servo controllers and motors, absolute main axis encoders, modern closed-loop controls and PC-based main operating software. We also discuss the original relay-based interlock systems that have been replaced with Programmable Logic Controllers (PLC) and have been interfaced into the new telescope control system. The modernization of both telescopes also includes many hardware upgrades to allow for remote observing and scripted automatic observations. These upgrades also include the modernization of shutter drives, windscreens and dome controls to improve the reliability and safety required for remote observing from an existing facility.