SER_RTS
if (ISSET(bits, SER_RTS)) {
SET(rbits, SER_RTS);
if (sc->sc_mcr & SER_RTS) {
sigon |= SER_RTS;
if (sigon & SER_RTS) {
sc->sc_mcr |= SER_RTS;
if (sigoff & SER_RTS) {
sc->sc_mcr &= ~SER_RTS;
onoff = (sc->sc_mcr & SER_RTS) ? 1 : 0;
ucom_modem(tp, SER_RTS, 0);
if (ISSET(sc->sc_mcr, SER_RTS) &&
(void)ucom_modem(tp, 0, SER_RTS);
if (!ISSET(sc->sc_mcr, SER_RTS) &&
(void)ucom_modem(tp, SER_RTS, 0);
ucom_modem(sc->sc_tty, SER_DTR | SER_RTS, 0);
#define SER_DRTS SER_DELTA(SER_RTS)