B&B Electronics 232PCI1B Appendix B RS-232 Pinouts, RS-232 Pinouts DTE, Description Direction

Appendix B: RS-232 Pinouts

Table 1: RS-232 Pinouts (DTE)
Name	Description			Direction			DB9M
							Pin
DCD	Data Carrier Detect			Input			1
RD	Receive Data			Input			2
TD	Transmit Data			Output			3
DTR	Data Terminal Ready			Output			4
GND	Signal Ground			-----			5
DSR	Data Set Ready			Input			6
RTS	Request to Send			Output			7
CTS	Clear to Send			Input			8
RI	Ring Indicator			Input			9
Table 2: Reference Cabling Table
		DB9 to DB25			DB9 to Null Modem Cabling
Name		DB9	To		DB9	DB9 Null		DB25 Null
		Pin	DB25		Pin
DCD		1	8		1	*			*
RD		2	3		2	3			2
TD		3	2		3	2			3
DTR		4	20		4	6			6
GND		5	7		5	5			7
DSR		6	6		6	4			20
RTS		7	4		7	8			5
CTS		8	5		8	7			4
RI		9	22		9	-			-

NOTE: In null cables, the DCD connection is usually connected to DSR at each end.

2 Channel RS-232 Handshaking loopback for Tx & Rx: Connect DB9 pins #7 & #8 together, and pins #4 & #6 & #1 together.

Documentation Number 232PCIXX4502 Manual Appendix B B -1

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