NEC Electra Elite 192, Hardware Manual

Page: 222 / 369

Issue 6 Electra Elite
5 - 76 Installing Electronic Telephone Units
5.8.3 Cabling
The information listed below applies when connecting the
VDH2(8)-U10 unit.
Normally the 10Base-T cables connected to the
VDH2(8)-U10 units cannot be directly connected to
another HUB or to a LAN terminal. A set of jumpers
is provided on the VDH2(8)-U10 to turn off the
station abilities for ports 1~7. In this case LAN
terminals can be connected directly to the
VDH2(8)-U10 ETU. Refer to
Figure 5-44
VDH2(8)-U10 ETU Jumpers for the layout of
jumpers on the KTU.
Port 8 is unique because the station abilities cannot
be separated by changing a jumper setting like
ports 1~7. Port 8 is to be used for cascading HUBs.
Connect Port 8 either to another VDH2(8)-U10 (Port
1~7) or an external HUB. In this case be sure to set
SW2 on the VDH2(8)-U10 to =. If SW2 is set to X,
then Port 8 is used as a regular coreline connection.
Refer to
Figure 5-45 10Base-T Cable Connections .
The VDH2(8)-U10 ETU can be used with 10Base-2
and 10Base-T cables. VDH2(8)-U10 ETU HUBs
can be cascaded using 10Base2 cables. The
10Base2 connector can also be used to connect the
VDH2(8)-U10 ETU to a LAN backbone. (Refer to
Figure 5-46 VDH2(8)-U10 ETU .) In this case, the 8
port is still used for coreline. The 10Base2 cable
interconnecting VDH2(8)-U10 ETUs must be
greater than 0.5 meters. Care should be taken so
the 10Base2 cables are neatly coiled. When the
10Base2 cables are connected to the VDH2(8)-U10
BNC connector, a terminating plug must be used if
this is the last device on the cable. Refer to
Figure
5-47 VDH2(8)-U10 ETU Connections .
Using the 10Base-2 cables is the preferred method
of cascading VDH2(8)-U10 ETU hubs since it does
not reduce the quantity of station ports that the ETU
can provide.