Installation guide

A-49
Cisco IGX 8400 Series Installation Guide, Release 9.3.3 and Later Releases
OL-1165-06
Appendix A System Specifications
Cabling Summary
Null Modem Cable
Figure A-4 shows a null modem cable that connects some of the 1200 and 2400 baud modems to the IGX
control and auxiliary ports.
Figure A-4 Null Modem Cable
External Clock Input Cabling
Two separate clock inputs exist, and can be used simultaneously on the IGX. They are labelled
External-1 and External-2. Both clock inputs require an EIA/TIA 422 balanced square wave signal at
either 1.544 or 2.048 MB per second.
Note Standard DS1 or E1 BITS clock sources using AMI bipolar pulse stream signals are not compatible with
IGX external clock inputs.
H8377
1
7
8
2
3
4
5
6
20
1
7
8
2
3
4
5
6
20
Table A-48 External Clock Cabling
Cable Parameter Description
Interface Balanced EIA/TIA 422
Suggested cable 24 AWG, individually shielded, 1- or 2-pair
Cable connector DB-15, subminiature, male. See Table A-49 for pinouts
Maximum cable length 50 ft (15 m)
Table A-49 External Clock Connector Pin Assignments
Pin No. Description
1 External Clk 1-A
9 External Clk 1-B
2 Shield ground pair 1
3 External Clk 2-A