Installation guide

ProMedia-100 Manual Page 5
3.0 INSTALLATION
This section describes the installation of the ProMedia-100 media converters, including location,
segment distance calculation and media connection.
3.1 Locating the Media Converter Unit
The compact and lightweight design of the ProMedia-100 media converter allows it to be easily
installed in most any location. A Velcro strip and a set of two metal clips and screws are included (either
may be used) for mounting the unit on a vertical surface such as a wall or cabinet, or for securing the unit
on a tabletop or shelf. The installation location is dependent upon the physical layout of the Ethernet
network and associated cabling. Make sure the unit is installed in a location that is easily accessible to
an AC power outlet or power strip, and where convection cooling is not inhibited.
3.2 Calculating Segment Distances
The media distance considerations are quite different for full duplex and for half-duplex (standard
Fast Ethernet) installations. Each of these situations is covered below in a separate section.
3.2.1 Segment Distances, Full Duplex
Full-duplex ports, such as are found in switching hubs and some NICs, can receive and transmit
signals simultaneously and do not experience collisions accordingly. There may be only two nodes
present on a full-duplex segment. Media distance rules are not the same as for standard (half-duplex)
Fast Ethernet because collision distance limitations are not a factor. Specifically, fiber segments can be
up to 2km for multimode and up to 15km for singlemode.
The ProMedia-100, with full-duplex operation as a standard feature, can be used in these
applications. When installing the ProMedia-100 in a full-duplex segment, it is important to consider the
combined overall segment length of both of the attached media types. The overall segment length is
calculated by adding together the segment lengths on both sides of the ProMedia-100 media converters.
The figure below illustrates how a ProMedia media converter is used to connect a multimode fiber
(100BASE-FX) with a twisted pair (100BASE-T) segment.
Segment length on each side of the ProMedia-100 media converter is measured as a percentage
of the maximum allowable standard media distance for the given media type. The percentages, when
added together, must not exceed 100%.
Media Distance Formula for ProMedia-100, full-duplex
:
X% + Y% <
100%
Where X = The segment distance on one side of the media converter divided by the Standard Maximum
Media Distance for that media type, x 100%
Where Y = The segment length on the other side of the media converter divided by the Standard
Maximum Media Distance for that media cabling type, x 100%
In the example figure shown above, the length of fiber Segment X is 1500m (4920 ft). This is
75% of the maximum allowable distance for multimode 100BASE-FX fiber full-duplex media (2000 m)
[75/2000 x 100% = 75%]. The length of twisted pair Segment Y is 10m (33 ft). This is 10% of the
maximum allowable distance for 100BASE-TX full-duplex twisted-pair media (100 m) [10/100 x 100% =
10%]. The total of the two percentages (75% + 10%) is 85%, which is allowable.
Note 1
: Where more than one media converter is used in one segment run, the percentages for
all of the cabling lengths in the run must be added together and must not exceed 100%.
In another instance, a ProMedia media converter is used to connect a singlemode fiber
(100BASE-FX) with a twisted pair (100BASE-T) segment. In this example, the length of fiber Segment X
is 8500m (27,880 ft). This is 57% of the maximum allowable distance for singlemode 100BASE-FX fiber