autoDialer V1.0.3
  (1) add ping function
  (2) add "AT+CPOF\n" before reset modem
  (3) add "MOdem Reset Time Interval"


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AutoDial API V1.0.4
  (1) send "AT+CPOF" before reset modem
  (2) add "DIAL_SetResetTime()" function (for U200 Modem, it needs 3000 ms reset time interval)