3Com SuperStack II 32x, Installation Manual

Page: 42 / 76

2-20 C
HAPTER
2: O
VERVIEW
When constructing your own X.21 adapter cables, the required cable
type is equivalent to Belden part number 9839. Cable length is limited
to CCITT standard V.11 Appendix I.2.
You can order the X.21 adapter cable from 3Com (part number
3C8021).
X.21 European Connector Compliances. For installations where
compliance to the European standard NET 1 is required, use an X.21
15-pin male connector (ISO 4903) to construct the RS-449-to-X.21
conversion cable. For compliance in Austria, Denmark, Finland,
Germany, and the United Kingdom, use M3-threaded attaching screws
with this connector.
ISDN Cable
(Model 52x )
To connect a model 52x bridge/router to an ISDN network, use an ISDN
cable with an RJ-45 connector. 3Com does not supply this cable.
Table 2-6 shows the pin assignments of the cable with both ends
terminated in RJ-45 connectors.
Table 2-6 ISDN Cable Pinouts
Pin No. Function Signal
1 Not connected NC
2 Not connected NC
3 Transmit data (plus) TXD+
4 Receive data (plus) RXD+
5 Receive data (minus) RXD-
6 Transmit data (minus) TXD-
7 Not connected NC
8 Not connected NC
SS2TRHWBook Page 20 Monday, May 5, 1997 3:11 PM