1.Check if the parameter in the software is set correctly (set again);
  2.If press positioning to start and then output (output again);
  3.Check if the machine is no reposition (modify);
  4.Check if the output serial-port comply with the port set by software (reset);
  5.Check if the earth wire is safe, static distracts the data wire (re-connect the earth);
  6.Replace computer serial-port and output test;
  7.Re-install the software and reset the test;
  8.Format the computer system and install the software to test;
  9.The serial-port of main board are damaged and need to repair or replace;