Data line and communication system thereof

The embodiment of the invention discloses a data line. The data line comprises a power supply cable for providing bus voltage; the first electronic tag chip and the second electronic tag chip are used for providing cable characteristics of the data line; wherein the first electronic tag chip and the second electronic tag chip are configured as follows: when the first power supply end is at a high level and the debugging end is at a low level, the first electronic tag chip and the second electronic tag chip are identified as near ends; when the first power supply end is at a low level and the debugging end is at a high level, the first power supply end is identified as a far end; and after the first electronic tag chip or the second electronic tag chip identifies the first electronic tag chip or the second electronic tag chip as a near end, the debugging end of the first electronic tag chip or the second electronic tag chip is converted from low level to high level. Through the above mode, a VCONN power supply