X.21 Pinouts

X.21, Male DB-15 Connector

Pin	CCITT	Description
9	103B	TxD-
2	103A	TxD+
3	105B	RTS-
10	105A	RTS+
4	104A	RxD-
11	104B	RxD+
5	106A	CTS-
12	106B	CTS+
13	115A	RxCLKi-
6	115B	RxCLKi+
7	113A	TxCLKo-
14	113B	TxCLKo+
8	n/a	GND
Shell	n/a	CGND