5 -4
C
hapter
5: P
erforming
T
roubleshooting
an d
D
iagnostic
T
ests
R unning th e G ro u p 2 Test
The Group 2 test is called the Network LoopbackTest. It tests the
3C509B and 3C509B-COMBO adapters'ability to transmit and
receive data over the network.This test requires installation of a
loopback plug at the adapter's transceiver connection. Or, you
can run the test on a nonproduction network on which only the
computer being tested is operating.
CAUTION:
Running the Group 2 test while connected to an
active network can cause intermittent failures.
Assembling a Loopback Plug
If you do not have a loopback plug, you can order one from your
authorized network supplier (3Com part number 3C537) or you
can make your own.To assemble the loopback plug, connect
two 50-ohm network cable terminators to aT connector, as
shown in Figure 5-1 .You can purchase the terminators from your
network supplier (3Com part number 3C535).
Starting th e Group 2 Test
To run the Group 2 Test on an EtherLink III adapter, follow
these steps:
1 Connect the loopback plug to the round BNC connector
on the back of the adapter.
2 Start the Configuration and Diagnostic Program, as
described earlier in this chapter.
