RS422串行口针脚定义图 引脚定义
计算机侧 RS-422 串行接口的插口是 25 针公插：
设备侧 RS-422 串行接口插头是 25 针母插：
引脚定义
Pin
Name
Dir
DescripTIon
1
GND
Shield Ground
2
SRI
Signal Rate Indicator
3
n/c
-
Spare
4
SD
Send Data
5
ST
Send TIming
6
RD
Receive Data
7
RTS
Request To Send
8
RR
Receiver Ready
9
CTS
Clear To Send
10
LL
Local Loopback
11
DM
Data Modem
12
TR
Terminal Ready
13
RR
Receiver Ready
14
RL
Remote Loopback
15
IC
Incoming Call
16
SF/SR
Select Frequency/Select Rate
17
TT
Terminal TIming
18
TM
Test Mode
19
GND
Ground
20
RC
Receive Twister-Pair Common
21
GND
Spare Twister-Pair Return
22
/SD
Send Data TPR
23
GND
Send TIming TPR
24
GND
Receive Timing TPR
25
/RS
Request To Send TPR
26
/RT
Receive Timing TPR
27
/CS
Clear To Send TPR
28
IS
Terminal In Service
29
/DM
Data Mode TPR
30
/TR
Terminal Ready TPR
31
/RR
Receiver TPR
32
SS
Select Standby
33
SQ
Signal Quality
34
NS
New Signal
35
/TT
Terminal Timing TPR
36
SB
Standby Indicator
37
SC
Send Twister Pair Common
