A preventive diagnostic system for a gas insulated switchgear, GIS, based on IEC 61850, the preventive diagnostic system comprising: a plurality of data acquisition systems, DASs, being disposed in the GIS and configured to receive sensing data of partial discharge from a plurality of partial discharge sensors when the partial discharge occurs; a central communication unit, CCU, operable to transfer the received sensing data to a server in real time; and the server operable to generate report data using the sensing data received from the CCU and to provide the report data to a user through an HMI screen, wherein each of the plurality of DASs is configured to generate an ICD file representing a content of the configuration of the respective DAS using a logical node designed for the preventive diagnostic system for a GIS and to provide the CCU with the ICD file, and wherein the CCU is arranged to perform a network connection so as to communicate with each DAS in compliance with IEC 61850 based on a content of the provided ICD file, the CCU comprising: a configuration tool operable to generate a database used for a system operation, configure a gateway system to which each DAS is connected and a system operable to configure each DAS, automatically generate tags, and select a value to be used from among a plurality of values of each DAS; an operation tool configured to control operations of the DASs; and a value viewer tool configured to monitor and control values received from the DASs. a plurality of data acquisition systems, DASs, being disposed in the GIS and configured to receive sensing data of partial discharge from a plurality of partial discharge sensors when the partial discharge occurs; a central communication unit, CCU, operable to transfer the received sensing data to a server in real time; and the server operable to generate report data using the sensing data received from the CCU and to provide the report data to a user through an HMI screen, wherein each of the plurality of DASs is configured to generate an ICD file representing a content of the configuration of the respective DAS using a logical node designed for the preventive diagnostic system for a GIS and to provide the CCU with the ICD file, and wherein the CCU is arranged to perform a network connection so as to communicate with each DAS in compliance with IEC 61850 based on a content of the provided ICD file, the CCU comprising: a configuration tool operable to generate a database used for a system operation, configure a gateway system to which each DAS is connected and a system operable to configure each DAS, automatically generate tags, and select a value to be used from among a plurality of values of each DAS; an operation tool configured to control operations of the DASs; and a value viewer tool configured to monitor and control values received from the DASs. a configuration tool operable to generate a database used for a system operation, configure a gateway system to which each DAS is connected and a system operable to configure each DAS, automatically generate tags, and select a value to be used from among a plurality of values of each DAS; an operation tool configured to control operations of the DASs; and a value viewer tool configured to monitor and control values received from the DASs.