Section 150-611-103
Revision 01
Page 7
system option. See Section 8 for System Settings
information. The MAL1 alarm can be disabled by
setting the margin alarm threshold to 0. All six
alarms can be inhibited by selecting DIS (disable) for
the ALM system option. The MNALRM can be
retired by executing the ACO option. This is
accomplished by depressing the SEL button on the
front panel. This turns the alarm off and replaces
the ALRM message by the ACO message. The
second part of the ALRM message, which defines
the cause of the alarm, remains. Both messages
remain until the alarm condition clears or another
alarm occurs. Disabling the ALM also retires an
ACO condition.
7.18
Pin 32, FUSEALARM, is driven to -48 V and
the front panel STATUS LED turns red
whenever the on board fuse opens.
7.19
The HLU-611’s front panel tri-color
STATUS
LED has the following states:
•
GREEN - Normal Operation
•
FLASHING GREEN - VHDSL Acquisition
•
FLASHING RED - Minor Alarm (For
conditions see Paragraph 7.17)
•
RED - FUSEALRM
•
YELLOW - Self Test in process or an HLU
loopback in effect (CREM or NLOC).
•
FLASHING YELLOW - The HLU is in an
ARMED state.
7.20
Depressing both the MODE and SEL
pushbuttons on the front panel for at least 3
seconds initiates a MANUAL loopback session. This
session allows the user to SEL one of four HiGain
loopbacks. The message, MAN LPBK, appears on
the front panel display followed by the message
NRE?. If the SEL button is now depressed, an
NREM loopback is executed and the message
changes from NRE? to NREM. If the MODE button
is depressed instead of the SEL button, NRE? is
replaced by NLO?. This now allows an NLOC
loopback to be executed with the SEL button.
Depressing the MODE button two more times yields
the CLO? (CLOC) and CRE? (CREM) customer
loopback options. This interactive button procedure
permits any of the four HiGain loopback to be
executed. Once a loopback is executed, it can be
terminated and the next loopback option presented
by depressing the MODE button. If neither button is
depressed for a period of 30 seconds, this manual
loopback session terminates and the normal margin
displays reappear. If this time-out occurs with an
active loopback in effect, the appropriate loopback
message appears in addition to the loop margin
messages. Once the manual loopback session
terminates, the loopback remains in effect until it
times-out in accordance with the user LBTO setting.
It can also be terminated by re-entering the manual
loopback mode and selecting another loopback.
Only 1 loopback can exist at any given time.
Depressing both buttons, again for 3 seconds,
terminates any active loopback, ends the MANUAL
loopback session and returns the display to normal.
Note that the loopbacks can be also initiated from
the RS-232 maintenance port by choosing the
LOOPBACK MODE, option “D” from the MAIN
MENU. This displays the Loopback Menu, shown in
Figure 14, from which any of the four loopbacks can
be initiated.
8. OPTIONS
8.01
The HLU-611 contains a non-volatile RAM
which stores the system option settings. No
dip-switches or jumpers are required to set the HLU-
611 configuration. The options are set via
pushbuttons on the front panel, through the RS-232
interface, or from the NMA interface and are
retained if shelf power is lost or if the HLU-611 is
unplugged. Table 2 lists the HLU-611 option
settings. Note that only those options enclosed by
quotes can be set by the front panel buttons. All 14
options can be set via the front panel RS-232
maintenance part. Figure 8 illustrates the same
options on the HLU-611 set-up menu.
8.02
The SETUP (MODE and SEL) momentary
pushbuttons are used to set the options
from the front panel. To initiate an OPTION
SETTING mode, depress the MODE button for 1
second and release. The message displayed on the
front panel alternates between the system
parameter and its current setting. Depressing the
SEL button steps the display through all possible
settings (one at a time) of the MODE (parameter)
being displayed. After the desired setting has been
chosen, depress MODE. This does two things.
First it updates the current displayed mode to the
setting chosen. It then selects the next configurable
parameter. After the last parameter has been
selected, the displays shows CONF/NO. If the
MODE button is now depressed, none of the
changed parameters are installed. If the SEL button
