Transceiver Jumper - 3Com NETBUILDER II Installation Manual

Ethernet Module Components 1-3
Connectors
The two connectors on the Ethernet module's connector/LED panel (shown in
Figure 1-1) provide access to the Ethernet network. The AUI connector, which supports
thick cable, is routed to a transceiver. The BNC connector, which supports thin cable, is
directly connected to the thin cable. Either the AUI or the BNC connector can be used,
but not both. See Table 2-1 in Chapter 2, Installation , for the AUI connector pin
assignments.
CAUTION: To eliminate cable noise emission in excess of FCC Part 15, subpart J, VDE
specification 0871 for Class A devices, all device cables should have connectors with
metallic backshells

Transceiver Jumper

For systems using thin Ethernet cables, the Ethernet module's on-board transceiver
supports line termination. The Ethernet module is shipped with the transceiver jumper
at the E1 position. This is the default setting, which does not support on-board
termination with a BNC connection. To achieve on-board termination with a BNC
connection, you must move the transceiver jumper to E2. See Figure 2-2 for the
location of jumpers E1 and E2.
Because on-board line termination provides direct connection to the Ethernet line, you
do not need T connectors and plug terminators. When on-board line termination is
not implemented, you must terminate the line manually.
Figure 1-2 shows BNC network connection with and without on-board line
termination.
NETBuilder II
NETBuilder II
Plug terminator T connector Plug terminator
Figure 1-2 Ethernet Connection with and without On-board Termination