X.21接口定义

X.21接口定义
X.21接口定义

 

X.21公头连接器

X.21母头连接器

X.21接口定义

Pinout for balanced X.21 (according to ISO4903)




Pin
Name
DTE I/O
Description
Type


1
Shield

Shield
Ground


2
T (A)

Transmit (A)
Data


3
C (A)

Control (A)
Control


4
R (A)

Receive (A)
Data


5
I (A)

Indication (A)
Control


6
S (A)

Signal Timing (A)
Timing


7
B (A) / unused

Byte Timing (A) or unassigned
Timing


8
G

Ground
Ground


9
T (B)

Transmit (B)
Data


10
C (B)

Control (B)
Control


11
R (B)

Receive (B)
Data


12
I (B)

Indication (B)
Control


13
S (B)

Signal Timing (B)
Timing


14
B (B) / unused

Byte Timing (B) or unassigned
Timing


15
 
 
unused
 

X.21交叉线定义

X.21
X.21


1
1


2
4


3
5


4
2


5
3


6
7


7
6


8
8


9
11


10
12


11
9


12
10


13
14


14
13


15