PD_RS232_S_TXO The transmit-data signal. Declaration#define PD_RS232_S_TXO See AlsoControl BitsPD_RS232_S_DTRPD_RS232_S_DSRPD_RS232_S_RTSPD_RS232_S_CTSPD_RS232_S_RXOPD_RS232_S_DCD