Section 150-611-100
Revision 02
Page 7
The HLU 611’s STATUS LED flashes RED for the
duration of a minor alarm condition. Alarms 4 and 5
can be inhibited by selecting NONE for the ESAL
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
through a 1000 ohm resistor 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
three 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 one loopback can 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.
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. Figure 8 illustrates the same options on
the HLU-611 set-up menu. The settings shown in
the second column represent the factory default
settings. The third column values (in parenthesis)
indicate the other parameter options.
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 one
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 display shows CONF/NO. If the
MODE button is now depressed, none of the
changed parameters are installed. If the SEL button
is depressed, a YES message is displayed and the
chosen changes are installed. In either case the
display returns to its normal mode. The display also
