Specifications

Cable Specifications C-21
Synchronous Serial Cable Assemblies and Pinouts
X.21
Figure C-10 shows the X.21 cable assembly. Table C-13 lists the DTE pinouts. Table C-14
lists the DCE pinouts. Arrows indicate signal direction: —> indicates DTE to DCE, and
<— indicates DCE to DTE.
Figure C-10 X.21 Cable Assembly
Table C-13 X.21 DTE Cable Pinouts (DB-60 to DB-15)
60 Pin Signal Description Direction 15 Pin Signal
J1-48
J1-47
GND
MODE_2
Shorting group – – –
J1-51
J1-52
GND
MODE_DCE
Shorting group – – –
J1-46 Shield_GND Single – J2-1 Shield GND
J1-11
J1-12
TxD/RxD+
TxD/RxD–
Twisted pair no. 3 —>
—>
J2-2
J2-9
Transmit+
Transmit–
H1974
60-pin connector (J1)
15-pin connector (J2)
Connectors are not to scale
J2-8
J2-15
J2-9
J2-1
J1-46
J1-45
J1-16
J1-15
J1-1
J1-30
J1-31
J1-60