Section 150-319-251
Revision 01
Page 9
ELU-319
DCE
FEMALE
MALE
2
5
3
2
5
3
RD (RECEIVE DATA)
TD (TRANSMIT DATA)
GND
DB9
DB9
DTE
DTE
TERMINAL
TERMINAL
3
2
7
DB25
Figure 3. ELU-319 DB-9 Pin-Outs. A standard RS-232
(DB-9) connector on the front panel provides access to
the menu interface feature via a dumb terminal.
9.05
To set the Margin Alarm Threshold, select
G–SYSTEM SETTINGS and then select G–
MAR(G)IN ALM THRES. Enter the minimum
acceptable alarm threshold, from 0 to 15 dB. If the
margin for HDSL Loop 1 or 2 drops
below this
value, the ELU-319 triggers a minor alarm, and the
front panel and status screen displays “MAL1” (Loop
1) or “MAL2” (Loop 2). Because a margin can never
be less than zero, setting a threshold of zero turns
this feature off.
9.06
To set the Clock, select B–SET CLOCK
from
the Main Menu. Enter the new date and
time. Press U to update the ERU system time and
date.
9.07
The Maintenance Port also provides several
screens that display System Performance
and Alarm Status information. Figures 13 through
24 illustrate these screens. Table 6 defines the
terms used in the Alarm and System Setting
screens. The illustrations of the System Setting and
ELU Status screens show factory defaults with
optional values or settings in parentheses.
10. LOOPBACK DESIGN DESCRIPTION
10.01
All HiGain ELU/ERU system loop-up codes
must be initiated from either the front panel
pushbuttons or from the maintenance terminal. The
HiGain system does not respond to any
in-band
codes.
10.02
Depressing both the MODE and SEL
pushbuttons on the front panel for at least
three seconds initiates a MANUAL loopback
session. This session allows the user to SEL one of
six HiGain loopbacks. The message “MAN LPBK”
appears on the front panel display (see Figure 4.)
followed by the message “NLO?”. If the SEL button
is now pressed, an NLOC loopback is executed and
the message changes from “NLO?” to “NLOC”. If
the MODE button is pressed instead of SEL button,
“NLO?” is replaced by “‘ND1?. This now allows an
NDU1 loopback to be executed (if it is a doubler
application) with the SEL button. If it is not a
doubler application, NRE? follows NLO?. If this
same routine is followed, all six loopbacks (NLOC,
NDU1, NREM, CLOC, CDU1, & CREM) are
presented and can be initiated in the sequence
listed. Note that NDU1 and CDU1 only can appear
in doubler applications. Once a loopback is
executed, it can be terminated and the next
loopback option presented by pressing the MODE
button. If neither button is pressed for 30 seconds
and no loopback is in effect, this manual loopback
session terminates and the normal margin displays
reappear. If any loopback is in effect, this 30-
second time-out is inhibited. The active loopback
and the manual loopback session continue until the
loopback times out in accordance with the user
LBTO setting. Only one loopback may exist at any
given time. Depressing both buttons, again for three
seconds terminates any active loopback, ends the
MANUAL loopback session, and returns the display
to normal.
10.03
Note that these same six loopbacks can be
initiated from the RS-232 maintenance port
by choosing LOOPBACK MODE, option D, from the
main menu. This displays the Loopback Menu,
shown in Figures 22 and 23, from which you can
initiate any of the six loopbacks.
10.04
The TLOS loopbacks (shown in Figure 4)is
controlled by a user switch option in the
ERU-412. When this option is enabled it forces the
ERU-412 into a logic loopback state when its G.703
input signal is lost. When this TLOS option is
disabled, it causes an AIS condition to occur at the
G.703 output of the ELU-319 when the G.703 input
to the ERU-412 is lost.
