DCE
DCE - RS-232 to TTL
<img src="https://www.db9-pinout.com/db9-pinout/db9-pinout.gif"></img>
Pin SIG. Signal Name DTE (PC) 1 DCD Data Carrier Detect in 2 RXD Receive Data in 3 TXD Transmit Data out 4 DTR Data Terminal Ready out 5 GND Signal Ground - 6 DSR Data Set Ready in 7 RTS Request to Send out 8 CTS Clear to Send in 9 RI Ring Indicator in
