Design a control framework for large mosaic cameras named RACS2-CCS and its application in WFST

In the field of time-domain sky surveys, traditional single-sensor cameras have a limited field of view, making it challenging to efficiently complete large-scale survey tasks. Cameras composed of multiple mosaicked sensors, enables telescopes to achieve wide-field, high-resolution imaging, greatly enhancing survey efficiency. The Camera Control System (CCS) is responsible for controlling the operation of devices in mosaic camera systems, monitoring their status in real-time, coordinating them to complete the full operational workflow, and ultimately generating scientific image data. In this paper, we present an in-depth study of the system architecture for large distributed mosaic cameras and we propose the RACS2-CCS framework, based on the second-generation Remote Autonomous Control System (RACS2). The core feature of RACS2-CCS is its event-driven mechanism. In this framework, we not only establish a unified component programming paradigm but also introduce a range of new features, including component management, image file management, and a site interface, addressing the limitations of RACS2 when applied to the control of large mosaic camera systems. RACS2-CCS was built through the gradual implementation of the hardware control layer, system control layer, and interface layer. RACS2-CCS was successfully applied to the CCS of the Wide Field Survey Telescope (WFST). During multiple joint debugging sessions, the system performed stably and successfully completed long-term observation tasks at the Lenghu observatory, verifying its efficiency and reliability in real-world operations.