Installation guide

ProMedia-100 Manual Page 9
4. Connect the Receive (RX) port (dark colored post) on the ProMedia-100 to the Transmit (TX) port
of the remote device. Use the non-color coded fiber strand for this.
5. The LINK LED corresponding to the fiber port, on the front of the product, will illuminate when a
proper connection has been established at both ends (and when power is ON in the units at each
end). If LINK is not lit after cable connection, the normal cause is improper cable polarity. Swap
the fiber cables on the product connector to remedy this situation.
3.3.3 Power Budget Calculations for Fiber Media
Receiver Sensitivity and Transmitter Power are the parameters necessary to compute the power
budget. To calculate the power budget of different fiber media installations, the following equations
should be used:
OPB (Optical Power Budget) = P
T
(min) - P
R
(min)
where P
T
= Transmitter Output Power, and P
R
= Receiver Sensitivity
Worst case OPB = OPB - 1dB(for LED aging) - 1dB(for insertion loss)
Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km]
where the “Cable Loss” for 62.5/125 and 50/125
µm (m.m.) is 2.8 dB/km,
and the “Cable Loss” for 100/140 (multimode) is 3.3 dB/km,
and the “Cable Loss” for 9/125 (singlemode) is 0.5 dB/km
The following data has been collected from component manufacturer’s (HP’s and Siemens’) web sites
and catalogs to provide guidance to network designers and installers.
Fiber
Port
Module
Speed,
Std. Mode
Std. km
fdx
(hdx)
Wave-
length
nm
Cable
Size
µm
X’mitr
Output
P
T ,
dB
R’cvr
Sens.
P
R ,
dB
Worst
OPB,
dB
Worst*
dist.
Km, fdx
typical
OPB,
dB
typical*
dist.
Km, fdx
100SC,
100ST
100Mb
FX
Multim
ode
2
(0.4)
1300 62.5/125
50/125
-20
-23.5
-31
-31
9.0
5.5
2.5
2.0
14
12
5
4
SC-SM,
ST-SM
100Mb
FX
Single
mode
18+
(0.4)
1300 9/125 -15 -31 14 28 17.5 35
* Note: The use of either multimode or singlemode fiber to operate at 100Mbps speed over long
distances (i.e., over approx. 400 meters) can be achieved only
if the following factors are both applied:
1. The 100Mb fiber segment must operate in full-duplex (FDX) mode, i.e. a switch (or equal external
unit such as a FDX NIC) must be used, and
2. The worst-case OPB of the fiber link must be greater than the fiber cable’s passive Attenuation.
(Attenuation = Cable loss + LED aging loss + Insertion loss + safety factor)
4.0 OPERATION
This section describes the operation of the ProMedia-100 media converters including power
supply requirements, up-link switch functionality, and a description of all LEDs.
4.1 Power Requirements, Power Supply Types
ProMedia-100 media converters require 5 watts of power and are designed to be used with an
external power supply. The external power supply unit supplied is one of two types; one version for AC
input power of 115-vac 60 Hz, and one version for 230-vac 50 Hz. The 115-vac version has a small
transformer integral with a convenience power outlet plug. The 230-vac version has a small transformer
integral with an IEC-type power plug for a user-supplied AC power cord with a convenience power outlet