Verilink PRISM 4001 (34-00244) Product Manual - Manual (Page 20)

Operation 3-2 PRISM 4001
12. DBU Active: This yellow LED lights when the dial
backup is active. It blinks as a dial backup connection is
established or shutdown.
13. DBU: The DBU jack provides a sync or async inter-
face for external dial backup equipment. Refer to sec-
tion Dial Backup Port in this chapter for more
information.
14. LOS: This LED lights with a loss of signal from the
DDS network.
15. OOS: This LED lights when an out-of-sync condition
is detected.
16. LOOP: This LED lights continuously when the net-
work interface is in a loopback of any kind.
17. TST: This LED lights continuously whenever the
BERT pattern generator is active, including during
loop, unloop, and FAR tests.
18. ERR: This LED lights when BERT pattern errors are
detected. At the end of a FAR test, it indicates the
results of the test as long as the FAR/LOC switch
remains in the FAR position.
Front Panel Testing
The previous section gave a brief description of each front
panel control and LED indicator. This section explains the front
panel test functions. Testing may also be performed using soft-
ware control from the 8100A Site Controller or the Terminal
Interface program (refer to the Terminal Operations chapter).
Test Switch
This switch (labeled FAR/LOC) is used for local testing.
When in the FAR position, the 4001 sends five seconds of
the V.54 loop pattern, then switches to the 511 pattern.
When transmitting a test pattern, the TST LED is lit contin-
uously. The ERR LED lights for one second when a bit
error or sync loss on the returned data is detected. After the
FAR test has been completed, the ERR LED is Off for
passed or On for failed.
When the test switch is returned to the center position, the
4001 sends five seconds of V.54 loop down code and then
returns to its normal operating mode.
When the Test switch is in the LOC position, the 4001 per-
forms a network LLB as shown on page 4-5, and the LOOP
LEDs light.
The test switch is also used when upgrading the 4001 soft-
ware. When Switch 2 position 6 is up, the test switch then
has the following functions:
The LOC position permits download at 19200 bps.
The middle position permits download at 38400 bps.
The FAR position permits download at 57600 bps.
Supervisory Port
This 8-pin modular RS-232 jack provides direct terminal
access for controlling the 4001 and gathering status and per-
formance data.
The supervisory port serves several functions. A terminal may
be connected to this port for external software control. A modem
may be connected for remote access. The port supports the call
on alarm feature. Refer to section SUPV Port Connection on
page 2-5 for connection information.
Dial Backup Port
This 10-pin modular RS232-level jack can provide an alter-
nate data path when the DDS network connection fails. This
port supports synchronous connection up to 64 kbps and
asynchronous connection up to 57.6 kbps.
If an internal modem or ISDN terminal adapter is installed
in the 4001, the Dial Backup Port is not used. A separate
connector on the rear of the unit is used to attach a tele-
phone or ISDN line.