Follow a four-step troubleshooting process: start with visual inspection, verify power, isolate faulty components, and validate the entire system to reduce downtime and improve reliability. With the widespread use of DAS, higher requirements for distribution automation terminal on-site testing have been put forward on account of limitations of field working conditions. Based on the requirement of relevant standards, this paper discusses automatic testing exploratory research, by. The handbook describes various power distribution system constructions and elements there-of, technical considerations, distribution automation infrastructure and functionality, communication aspects, special automation applications and life cycle aspects. It also reveals some trends and future. With our on-site support, RTA & IoT provides experienced field engineers who work alongside your maintenance team to troubleshoot, diagnose, and resolve issues in real time. Our experts ensure minimal downtime and optimized system performance through both reactive and preventive support. This forces teams to manage devices manually, which increases errors and overhead. Compared to the AireOS WLC, the C9800 software has been rewritten from scratch to leverage the benefits of Cisco IOS XE, and the configuration model has been made more modular.