Mode-Conditioning Patch Cord; Patch Cord Configuration Example - Cisco 6509 - Catalyst Chassis Switch Installation Manual

Appendix B Transceivers, Module Connectors, and Cable Specifications
Table B-19 Port Mode 2 Signaling and Pinouts (Port Mode Switch Out) (continued)
Console Port
4 (GND)
5 (GND)
6 (TxD)
7 (DSR)
8 (CTS)
1. Pin 1 is connected internally to Pin 8.

Mode-Conditioning Patch Cord

When using the long wavelength/long-haul (LX/LH) GBIC with 62.5-micron diameter MMF, you must
install a mode-conditioning patch cord (Cisco product number CAB-GELX-625 or equivalent) between
the GBIC and the multimode fiber (MMF) cable on both the transmit and receive ends of the link. The
9.8 foot (3 meter) patch cord is required for link distances greater than 984 feet (300 meters).
Note We do not recommend using the LX/LH GBIC and MMF without the patch cord for very short link
distances of 33 to 328 feet (10 to 100 meters). The result could be an elevated bit error rate (BER).
The patch cord is required to comply with IEEE standards. IEEE found that link distances could not be
met with certain types of fiber-optic cable due to a problem in the center of some fiber-optic cable cores.
The solution is to launch light from the laser at a precise offset from the center by using the patch cord.
At the output of the patch cord, the LX/LH GBIC complies with the IEEE 802.3z standard for
1000BASE-LX.

Patch Cord Configuration Example

Figure B-19
Figure B-19 Patch Cord Configuration
1000BASE-LX/LH
OL-5781-04
1
shows a typical configuration using the patch cord.
Patch
cord
Rx
Patch
port
panel
Tx
Link span greater than 984 ft
Console Device
GND
GND
Output
Input
Input
Building Patch
cable plant cord
Patch
panel
(300 m)
Catalyst 6500 Series Switches Installation Guide
Tx
1000BASE-LX/LH
port
Rx
Cables
B-29