Cabletron Systems MicroMMAC 24T MICROMMAC- - Manual (Page 25)

REQUIREMENTS/SPECIFICATIONS
2-6
Mixed Cable Types
If multiple cable types exist in network, compensations must be made for
the different cable attenuations. Type 6 and Type 9 cables can run only 2/3
the distance of Type 1. Therefore 10 meters of Type 1
≈
6.6 meters of Types
6 and 9.
2.1.3 Multimode Fiber Optic Cable Specifications
Table 2-6 shows specifications for the Multimode Fiber Optic Cable
supported by TPIM-F2
.
Maximum Trunk Lengths
The maximum trunk cable length between the MicroMMAC-T and other
active devices is equal to the maximum drive distance as shown in
Table 2-6. For passive devices, the combined length of twice the longest
trunk cable, plus the longest lobe cable attached to the passive ring
segment, must not exceed the Maximum Drive Distance Trunk Length.
Attenuation
Fiber optic cable must be tested with an attenuation test set adjusted for an
850 nm wavelength. This test ensures that a cable’s signal loss is within
acceptable limits. Table 2-6 shows the attenuation for each Multimode
cable type.
Table 2-6. Multimode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Drive Distance
50/125
µ
m 13.0 dB or less The maximum allowable fiber
optic cable length is 2 km
(2187.2 yards). However, IEEE
802.5 specifications allow for a
maximum of 1 km (1093.6
yards).
62.5/125
µ
m 16.0 dB or less
100/140
µ
m 19.0 dB or less