RS232串口定義
標準的RS232串口為25針的接口，我們的pc上常用的是9針的串行接口省略了一些引腳:
設備側為25針母插:
|
RS232串口引腳定義 |
|
Pin |
Name |
ITU-T |
Dir |
Description |
|---|---|---|---|---|
|
1 |
GND |
101 |
|
Shield Ground |
|
2 |
TXD |
103 |
|
Transmit Data |
|
3 |
RXD |
104 |
|
Receive Data |
|
4 |
RTS |
105 |
|
Request to Send |
|
5 |
CTS |
106 |
|
Clear to Send |
|
6 |
DSR |
107 |
|
Data Set Ready |
|
7 |
GND |
102 |
|
System Ground |
|
8 |
CD |
109 |
|
Carrier Detect |
|
9 |
- |
|
- |
RESERVED |
|
10 |
- |
|
- |
RESERVED |
|
11 |
STF |
126 |
|
Select Transmit Channel |
|
12 |
S.CD |
? |
|
Secondary Carrier Detect |
|
13 |
S.CTS |
? |
|
Secondary Clear to Send |
|
14 |
S.TXD |
? |
|
Secondary Transmit Data |
|
15 |
TCK |
114 |
|
Transmission Signal Element Timing |
|
16 |
S.RXD |
? |
|
Secondary Receive Data |
|
17 |
RCK |
115 |
|
Receiver Signal Element Timing |
|
18 |
LL |
141 |
|
Local Loop Control |
|
19 |
S.RTS |
? |
|
Secondary Request to Send |
|
20 |
DTR |
108 |
|
Data Terminal Ready |
|
21 |
RL |
140 |
|
Remote Loop Control |
|
22 |
RI |
125 |
|
Ring Indicator |
|
23 |
DSR |
111 |
|
Data Signal Rate Selector |
|
24 |
XCK |
113 |
|
Transmit Signal Element Timing |
|
25 |
TI |
142 |
|
Test Indicator |
