Cabletron Systems EMM-E6 User Manual

•

Temperature: Multi-pair PVC 24 AWG telephone cables typically 
have an attenuation of approximately 8-10 dB/100 m at 20

°

C (68

°

F). 

The attenuation of PVC insulated cable varies significantly with 
temperature. At temperatures greater than 40

°

C (104

°

F), we strongly 

recommend using plenum-rated cable to ensure attenuation remains 
within specification.

When connecting a multimode fiber optic link segment to the EMM-E6 
(using an EPIM-F1/F2), ensure the network meets the following 
requirements:

•

Cable Type: Use the following multimode fiber optic media:

-

50/125 

µ

m fiber optic cabling

-

62.5/125 

µ

m fiber optic cabling

-

100/140 

µ

m fiber optic cabling

•

Attenuation: You must test the fiber optic cable with a fiber optic 
attenuation test set adjusted for an 850 nm wavelength. This test 
verifies that the signal loss in a cable falls within the following 
acceptable levels:

-

13.0 dB or less for a 50/125 

µ

m fiber cable segment

-

16.0 dB or less for a 62.5/125 

µ

m fiber cable segment

-

19.0 dB or less for a 100/140 

µ

m fiber cable segment

•

Budget and Propagation Delay: When you determine the maximum 
fiber optic cable length to incorporate fiber runs into your network, you 
must calculate and consider the fiber optic budget (a total loss of 
10.0 dB or less is permissible between stations) and total network 
propagation delay.

To determine the fiber optic budget, combine the optical loss due to 
the fiber optic cable, in-line splices, and fiber optic connectors. 
Typical loss for a splice and connector (together) equals 1 dB or less.

ICH1Book  Page 3  Tuesday, August 6, 1996  3:06 PM