The function set-serial-port-state changes various aspects of the state of the serial port associated with serial-port .
The argument
dtr
, if supplied, controls the DTR line. A true value means set and
nil
means clear. If
dtr
is not supplied, the state is unchanged.
The argument rts controls the RTS line in the same way.
The argument break controls the break state of the data line in the same way.