Abstract: The on-line monitoring system for automation equipment includes the master station and the substation. The online monitoring system for automatic equipment is the hardware and software system that is installed in the control center. It is responsible for communicating with online monitoring substations. And it has completed information processing, analysis and distribution. The substation of the online monitoring for automation equipment is the hardware and software system installed at the plant, which has completed protocol conversion, information collection, processing, control and storag. And it has send information to the master station according to requirements.