dtr
https://en.wikipedia.org/wiki/Data_Terminal_Ready
Dtr
https://en.wikipedia.org/wiki/Data_Terminal_Ready
Data Terminal Ready (DTR) is a control signal in RS-232 serial communications, transmitted from data terminal equipment (DTE), such as a computer, to data communications equipment (DCE), for example a modem, to indicate that the terminal is ready for communications and the modem may initiate a communications channel.. The DTR signal is present on pin 20 of the 22-wire RS-232 interface using a …