Monitoring device of two channels bus data in network system

The present invention, the first channel unit for transmitting and receiving data with the network bus, and transmitting and receiving data by converting the data received by the MII; A second channel unit for transmitting and receiving data with the network bus, and transmitting and receiving data by converting the data received by the MII; The first channel unit and a CPU which are sent and received to recognize the carrier detection signal (CRC) of MII data to be received from the second channel unit; And performing data communication with the CPU and from the MII data received through the CPU characterized in that it comprises a monitor for monitoring each channel data.