Black Box V.24/X.21, User Manual, Page: 8 / 9

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V.24/X.21 AND X.21/V.24 INTERFACE CONVERTERS
Figure 6-1. IC933A Pinning.
RTS
4
10
3
C-b
C-a
CTS
V.24 DTE/X.21 DCE
Schematic Diagram
V.24 (DTE) X.21 (DCE)
DB25 (Male) DB15 (Male)
DCD
TC
RC
TD
RD
8
15
17
2
3
12
5
13
6
9
2
11
4
I-b
I-a
S-b
S-a
T-b
T-a
R-b
R-a
+
-
+
-
+
-
DSR
DTR
Signal GND
Protective
GND
Shield
20
7