The Dome Auto Control System of the 1.2m Telescope at Yunnan Observatories

Dome automation is very important for improving data quality and reducing observers' workload. For the dome of the 1.2m Telescope at Yunnan Observatories, an automation control system is designed to avoid the occlusion effect caused by the dome during observation. The dome has a special structure with two hemispheres that can be opened horizontally with its rotation driven by tire friction. This auto control system uses an embedded system to control the dome by voltage conversion and remote network communication. The embedded device is FL2440 and its operating system is Linux. This architecture uses 8 Hall sensors and 3 magnets to determine the position of the dome. Test result indicates that its position resolution accuracy reaches to 15°. Details of the instruction set are given. After two months of trial, we find that the system is secure, stable and reliable. It can also meet the needs of regular observations.