114 PPC-105 User's ManualTable C-5: COM3 RS-232 serial portPin Signal1 DCD2 RxD3 TxD4 DTR5 GND6 DSR7 RTS8 CTS9 RITable C-6: COM4 RS-232 serial portPin Signal1 DCD2 RxD3 TxD4 DTR5 GND6 DSR7 RTS8 CTS9 RI15234 9678C.5 COM3 RS-232 serial port connector(CN2-1)C.6 COM4 RS-232 serial port connector(CN2-2)