PLC CONTROL SYSTEM IN AUTOMIBILE PAINTING PROCESS AND OPERATING METHOD THEREOF

摘要

The present invention relates to a PLC control system using an MODBUS protocol, which is capable of securing a minimum authentication and encryption required for transmitting data between an EMS server and a plurality of PLC devices, and integrity of a message, and an operating method thereof. The automobile painting shop based PLC control system according to an embodiment of the present invention comprises: a plurality of PLC devices (100); a plurality of PLC agents (710); a plurality of EMS agents (210); an EMS server (200); and a ZigBee network (300) which provides a wireless communication network between the plurality of PLC agents (710) and the plurality of EMS agents (210). The PLC agent (110) encrypts the measurement data by using a Modsec flame and transmits the encrypted measurement data to the corresponding EMS agent (210) through the ZigBee network (300). The EMS agent (210) decrypts the received encrypted measurement data into the original measurement data by using a preset key and transmits the decrypted measurement data to the EMS server (200).