It seems that your device is configured for hand shaking by default. You can (and should) use
tcsetattr
to configure your device. You may also try to use the
TIOCMBIS
ioctl command to set the DTR and RTS state.
You can only set the state of the output pins RTS and DTR. The state of the input pins DCD, DSR, RI, and CTS can only be read.
You should read the
Linux Serial HOWTO[
^] and the
Linux Serial Programming HOWTO[
^].