3Com 52x, 32x manual 6ISDN Cable Pinouts, Pin No Function Signal

2-20CHAPTER 2: OVERVIEW

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 To connect a model 52x bridge/router to an ISDN network, use an ISDN (Model 52x ) 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 2-6ISDN 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