A data converter includes a signal input port, a processing unit, and an output port. The signal input port includes a number of ports for connecting to corresponding ports of an electronic device and receiving waveform signals from the electronic device. The processing unit includes a port detection module for detecting which port of the signal input port is receiving the waveform signals and a data conversion module including a number of conversion sub-modules, each conversion sub-module corresponds to one port of the signal input port. When the port detection module detects the port receiving the waveform signals, the conversion sub-module corresponding to the detected port is enabled and converts the waveform signals to digital data. Then the output port outputs the digital data to a computer, and the communication state of the port of the electronic device is analyzed via the computer based on the digital data.