Serial Programming Guide for POSIX Operating Systems(4)

Appendix A, Pinouts

RS-232 Pinouts

     Figure  - RS-232 Connector

                      

Table 12 - RS-232 Signals
Pin	Description	Pin	Description
1	Earth Ground	14	Secondary TXD
2	TXD - Transmitted Data	15	Transmit Clock
3	RXD - Received Data	16	Secondary RXD
4	RTS - Request To Send	17	Receiver Clock
5	CTS - Clear To Send	18	Unassigned
6	DSR - Data Set Ready	19	Secondary RTS
7	GND - Logic Ground	20	DTR - Data Terminal Ready
8	DCD - Data Carrier Detect	21	Signal Quality Detect
9	Reserved	22	Ring Detect
10	Reserved	23	Data Rate Select
11	Unassigned	24	Transmit Clock
12	Secondary DCD	25	Unassigned
13	Secondary CTS

RS-422 Pinouts

 

                                 

             

Pin	Description	Pin	Description
1	Earth Ground	14	TXD+
2	TXD- - Transmitted Data	15	Transmit Clock-
3	RXD- - Received Data	16	RXD+
4	RTS- - Request To Send	17	Receiver Clock-
5	CTS- - Clear To Send	18	Unassigned
6	DSR - Data Set Ready	19	RTS+
7	GND - Logic Ground	20	DTR- - Data Terminal Ready
8	DCD- - Data Carrier Detect	21	Signal Quality Detect
9	Reserved	22	Unassigned
10	Reserved	23	DTR+
11	Unassigned	24	Transmit Clock+
12	DCD+	25	Receiver Clock+
13	CTS+

RS-574 (IBM PC/AT) Pinouts(公头)

 

 

                 

Pin	Description	Pin	Description
1	DCD - Data Carrier Detect	6	Data Set Ready
2	RXD - Received Data	7	RTS - Request To Send
3	TXD - Transmitted Data	8	CTS - Clear To Send
4	DTR - Data Terminal Ready	9	Ring Detect
5	GND - Logic Ground

SGI Pinouts

          

Pin	Description	Pin	Description
1	Earth Ground	6	DSR - Data Set Ready
2	TXD - Transmitted Data	7	GND - Logic Ground
3	RXD - Received Data	8	DCD - Data Carrier Detect
4	RTS - Request To Send	9	DTR - Data Terminal Ready
5	CTS - Clear To Send

 

Appendix B, ASCII Control Codes

 

ASCII中的控制字符如下

             

Name	Hex	Name	Hex	Name	Hex
NUL	00	SOH	01	STX	02
ETX	03	EOT	04	ENQ	05
ACK	06	BEL	07	BS	08
HT	09	NL	0A	VT	0B
NP,FF	0C	CR	0D	SO	0E
SI	0F	DLE	10	XON,DC1	11
DC2	12	XOFF, DC3	13	DC4	14
NAK	15	SYN	16	ETB	17
CAN	18	EM	19	SUB	1A
ESC	1B	FS	1C	GS	1D
RS	1E	US	1F