D-Link DE-81 6TP User manual

Table of Contents
About this Guide .............................................
1
Rack Mounting ................................................
2
Installing Network Cables..............................
3
Station Connections with
Twisted-Pair Cable...
...................................... 4
Hub-to-Hub connections with
Twisted-Pair Cable
........................... 4
Thin Coaxial Cable Connections.. .......
.7
Thick Coaxial Cable Connections
.... ...9
Connecting Power..........................................
9
LED Indicators.............................................
10
Specifications ................................................
11
Rev. 06 (April ‘98)
6DE824TP..06
Printed In China

About this Guide
This guide provides instructions for instal-ling all
of the products described below. These D-Link@
Ethernet Hubs are all Plug and Play compliant for
easy installation.
/ -
\
DE81 2TP+
DE-81 6TP
DE-824TP
When designing your cable configuration, it is
necessary to strictly observe the Ethernet cabling
rules. This manual assumes familiarity with the
fundamental Ethernet cabling rules and limits; it
only describes the details of cable connection.
1

Rack Mounting
The Ethernet Hub may stand alone, or may be
mounted in a standard 19-inch equip-ment rack.
Rack mounting produces an orderly installation
when you have a number of related network
devices. Use the six supplied screws to fasten the
supplied mounting brackets to either end of the
hub, then fasten the hub into the rack.
2

Installing Network Cables
Your Ethernet Hub is denominated as an 12-port,
or 16-port, or 24-port Ethernet Hub according to
the number of its front-panel
1OBaseT ports.
Additionally it has two ports whose connectors are
on the rear panel: one lOBase2 port (BNC
connector), and one lOBase5 port (AUI connector).
These two un-numbered rear-panel ports are
logically equivalent with the numbered ports on
the front panel of the Ethernet Hub.
By using a rear-panel connector of the Ethernet
Hub to connect into an existing coaxial network
cable, you can add on a star-topology
subnet,
connected through the Ethernet Hub’s numbered
front-panel ports. Alternatively, you can connect
into an existing star-topology through a front
panel port of the Ethernet Hub, and then add on a
bus-topology subnet by connecting the subnet bus
to a rear-panel connector of the Ethernet Hub
(irrespective of any star-topology subnet that may
also be supported by the Ethernet Hub’s front-
panel ports). In either case, the unused rear-
panel connector always remains available to
connect a second coaxial cable (alternative type of
coaxial cable).
When the Ethernet Hub has no coaxial trunk
connection, then both of the rear panel connectors
remain
available for coaxial station-cable
connections. It is useful to keep this in mind
when you have some station equipment whose
adapters have no 1OBaseT port (RI-45 connector),
and thus can only be connected to the hub through
a coaxial cable.
3

Connect each station to the Ethernet Hub by
means of a twisted-pair straight cable
(10BaseT
cable, Category 3, 4, or 5). Plug one RJ-45
connector into a front-panel port of the Ethernet
Hub, and plug the other
RJ-45 connector into the
station’s Ethernet adapter.
w ’
UTP cable
RJ-45
connector
Hub-to-hub connection between Model DE-
812TP+ Ethernet Hubs requires a 1OBaseT
crossover cable. In making a hub-to-hub
4

connection involving a Model DE-816TP or Model
DE-824 Ethernet Hub, there is the alternative of
using a straight cable.
Internal Crossover Features
The Model DE-816TP Ethernet Hub and DE-
824TP Ethernet Hub feature internal cross-over
alternatives for Port 1:
+ Model DE-816TP Ethernet Hub
The port numbered as Port 1 is identical with
each of the other numbered ports. But Port 1
is specially equipped with an alternative
connector, labeled “Uplink.” The Uplink
connector is wired to the same conductors as
the Port 1 connector, but with certain pin
positions interchanged to provide a cross-
over, and thus allow use of a straight cable to
make a hub-to-hub connection.
Keep in mind that the Uplink connector is not
an independent-port. It is only an alternative
connector to Port 1, to facilitate hub-to-hub
cabling. Port 1 is fully occupied whenever (1)
a hub-to-hub connection is made through its
Uplink connector, or (2) any kind of
connection is made directly through the Port
1 connector
Below in this manual, the term “Uplink
selected” will mean, as to the Model DE-
816TP Ethernet Hub in question, that the
subject connection is made through the
Uplink connector
5

+ Model DE-824TP Ethernet Hub
The connector numbered as Port 1 is equipped
with a switch labeled “Uplink” When the
Uplink switch is in the “off (tall) position, the
Port 1 connector is wired “straight” to the
supporting circuitry, and Port 1 is then
identical with each of the twenty-three other
numbered ports. When the Uplink switch is
in the “on” (depressed) position, a pin inter-
change is switched into the wiring for the
Port 1 connector, to provide a cross-over, and
thus allow use of a straight cable to make a
hub-to-hub connection.
Below in this manual, the term “Uplink
selected” will mean, as to the Model DE-824TP
Ethernet Hub in question, that the subject
connection is made through Port 1 and the
Uplink switch is in its “on” (depressed)
position.
Rules for Using the
Uplink Feature
Uplink should never be selected for a station cable
connection. And Uplink should never be selected
for a hub-to-hub connection through a crossover
cable (because the crossover in the connector
wiring would cancel out the crossover in the
cable).
Uplink
should be selected only for making a hub-
to-hub connection with a straight cable. When
Uplink is selected at one end of a straight cable,
Uplink must not be selected at other end of that
cable. (If Uplink were selected at both ends of a
straight cable, then the built-in crossovers of the
6

two connectors would cancel one another, and the
hub-to-hub connection would fail.)
Thus the rule for making a hub-to-hub connection
with twisted-pair cable is as follows:
To make a hub-to-hub connection with a
straight cable, Uplink must be selected at
one end of the cable, and Uplink must not
be selected at the other end of the cable.
To make a hub-to-hub connection with a
cross-over cable,
Uplink must not be
selected at either end of the cable.
To connect the Ethernet Hub to a thin coaxial
cable (lOBase2 cable, also known by its
wire-
standard name, RG58A/U, and a variety of other
informal names), first twist a BNC T-connector
onto the rear-panel BNC connector of the
Ethernet Hub. Then twist the shell of the cable’s
connector onto either leg of the BNC T.
If the thin coaxial cable continues on to other
nodes, then twist the shell of the continuation
cable onto the remaining leg of the BNC T. If
there is no continuation (the Ethernet Hub is at
the end of the coaxial cable), then it is necessary to
twist a 50-ohm terminator onto the remaining
open leg of the BNC T.
7

Thin coax Segment
v
Sometimes several Ethernet Hubs must be co-
located to support a larger array of stations than
can be handled by a single Ethernet Hub. Then it
is useful to stack the Ethernet Hubs by joining
their BNC connectors with 0.5 meter patches of
thin coaxial cable. Such stacking is just a special
case of thin coaxial cable connection as treated
above, and the terminator rule is the same: If the
stack is at the end of the incoming cable, then a
50-ohm terminator must be substituted for the
continuation cable shown in the stacking diagram
below.
Tonext node
8