The present invention includes a master device and a plurality of slave devices that transmit and receive packets through Modbus, and a Modbus analyzer that acquires the packets and monitors the operation status of the plurality of slave devices based on the packets, When a first slave device among a plurality of slave devices is in an abnormal operating state, the Modbus analyzer transmits abnormal state information of the first slave device to a set user device, and provides a Modbus RTU multi-drop system.
展开▼
