ocr: signal Description RinNumber Pin Number on2B-Pin: ongrin conecton connector TxD Transmit Data 2 3 RXD Receive Data 3 2 RTS Request To Send - 7 CTS Clear To Send 5 8 DSR Data Set Ready SG Signal Ground 7 5 DCD Carrier Detect 8 1 DTR Data lerminal Ready 20 RI Ring Indicator 22 y