at200j intelligent maintenance and secondary error-proof system is a total error-proof solution exclusively against misoperation in the maintenance and secondary links. it is mainly composed of maintenance error-proof management software, a maintenance error-proof host, a maintenance key, an intelligent maintenance lock, maintenance blocking accessories and an intelligent secondary error-proof device. the system employs the maintenance error-proof technology to turn “human control” of operational safety risk prevention involving maintenance work into “control by technology”, which effectively avoids misoperation and ensures human and equipment safety during maintenance.