MULTISERVER 500
48
You can use two Multiserver 500s as a diagnostics
tool. Simply connect two Multiserver 500s back to
back and bench-test them. To do this, set both
muxes to internal clock and select a composite
clock rate. Once you’ve selected a composite clock
rate, you must set both the local and remote muxes
to the same rate. The procedure is as follows (see
Figure 7-1):
1. Connect a crossover cable between the
COMPOSITE connectors of the two units.
2. Set the clock rate (9600) of the local unit:
>COM C=I R=9600 <cr>
3. Save the clock rate.
>SA
4. At the remote unit, repeat steps 2 and 3.
NOTE: Both Multiserver 500s must be set to the
same composite clock rate. Otherwise, the
system will lock up.
Other diagnostic tests are built into the
Multiserver. In addition to the user-initiated tests,
the Multiserver 500 undergoes an automatic self-test
during power-up.
7.1 Automatic Self-Test
This is a series of tests performed in the following
sequence:
• DSP Test
• Checksum Test
• RAM Test
• Composite Loopback Test
• Data Channel Loopback Test
If the DSP test fails, all LEDs will turn on and the
unit will remain in this loop. If any other test fails,
the TM indicator will flash, and the nature of the
problem will be displayed on the LCD.
7.2 User-Initiated Tests
As an aid to installation and fault isolation, the
Multiserver 500 incorporates a set of user-initiated
diagnostic tests: self-test, local and remote data
loopback, local and remote voice/fax loopback, and
local and remote composite loopback. You can start
these tests either from the LCD/keypad or from an
asynchronous terminal connected to the CMD IN
(Command Port) connector.
7. Diagnostics and Troubleshooting
DATA SOURCE
LOCAL
MULTISERVER 500
REMOTE
MULTISERVER 500
RxC
RxD
TxD
TxC
Set for
Internal
Clock
RxC
RxD
TxD
TxC
Set for
Internal
Clock
Figure 7-1. Clocking, with Multiserver 500s Connected in a Back-to-Back Hookup.