DOP-100 Series Transition Manual Software Interface Conversion 2.7 Conversion of COM port Transitioning from DOP-B to DOP-100 does not cause changes to the COM port. Only the communication interface switches from COM1 to COM2 when converting from DOP-B03S210 2 and DOP-B07S410. DOP-B03S210 When you set COM1 of DOP-B03S210 as RS422, it automatically converts to COM2 as RS422 on DOP-103BQ. February, 2019 2-13