F u l l - s i z e C P U C a r d F S B - 8 6 8 G R e v . BChapter 2 Quick Installation Guide 2 - 107 External Speaker(-) 8 I2C Bus SMB DataNote: Pin 5, 7 closed: Internal Buzzer Enable2.12 RS-232 Serial Port Connector (COM1)Pin Signal Pin Signal1 DCD 2 RXD3 TXD 4 DTR5 GND 6 DSR7 RTS 8 CTS9 RI 10 N.C2.13 RS-232/422/485 Serial Port Connector (COM2)Pin Signal Pin Signal1 DCD(422TXD-/485DATA-) 2 RXD(422RXD+)3 TXD(422TXD+/485DATA+) 4 DTR(422RXD-)5 GND 6 DSR7 RTS 8 CTS9 RI 10 N.C2.14 IrDA Connector (IR1)Pin Signal1 +5V2 N.C3 IRRX4 GND5 IRTX6 N.C