Alarm option for digital loop carrier (dlc) feed, Retiring system alarms – ADC H2TU-C-231 User Manual

Page 49

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LTPH-UM-1109-01, Issue 1

Testing

H2TU-C-231 List 2

January 9, 2002

41

Alarm Option for Digital Loop Carrier (DLC) Feed

To improve HiGain HDSL2 compatibility with the switch-to-protect features used in DLC feeder applications, the
H2TU-C-231 has an Alarm Pattern (ALMP) option that allows you to select either an AIS or LOS DS1 output
payload for the following alarms:

LOSW on any loop

LOS DS1

Retiring System Alarms

To retire a system alarm, press the SEL pushbutton to execute an Alarm Cutoff (ACO). An ACO turns the alarm
off and replaces the

ALRM

message with an

ACO

message. The second part of the

ALRM

message, which defines

the cause of the alarm, remains. Both parts of the message remain until the alarm condition clears or another higher
priority alarm occurs.

xxx-DBER

DS1 Bit Error Rate

The DS1 BER has exceeded the set
threshold limits of approximately 10

-6

.

(xxx denotes either TUC or TUR. If TUC
and TUR occur at the same time, then TUC
displays.)

Select DIS for the DBER system option.

LOF

Loss of Frame

The DS1 input does not contain the ESF or
SF frame pattern setting of the FRMG
option.

Change FRMG option to AUTO or UNFR.

PRMF

Performance Report
Messaging - Far End

Indicates H2TU-R PRM-FE BER threshold
is exceeded.

Set DBER threshold to DIS.

PRMN

Performance Report
Messaging - Near End

Indicates H2TU-R PRM-NE BER threshold
is exceeded.

Set DBER threshold to DIS.

xxx-HBER

(c)

HDSL2 Block Error
Rate

The HDSL2 BER has exceeded the set
threshold limits of 10

-6

or 10

- 7

. (xxx

denotes either TUC or TUR. If TUC and
TUR occur at the same time, then TUC
displays.)

Select NONE for the HBER system option.

xxx-MAL

(c)

Margin Alarm

The margin on the HDSL2 loop has
dropped below the minimum threshold
value set for the system. (xxx denotes
either TUC or TUR. If TUC and TUR occur
at the same time, then TUC displays.)

Set the Margin Alarm Threshold option to
0 (zero).

xxx-LA

(c)

Loop Attenuation

The attenuation on the HDSL2 loop has
exceeded the maximum value set for the
HDSL2 loop attenuation threshold. (xxx
denotes either TUC or TUR. If TUC and
TUR occur at the same time, then TUC
displays.)

Set the HDSL2 Loop Attenuation
Threshold option to 0 (zero).

(a) The message,

ALRM

, displays prior to any alarm message.

(b) Message displays repeatedly as long as the alarm condition exists and is not included in the priority order.
(c) Only these alarms assert the System Alarm bus on pins 20 and 21 of the card-edge connector if the ALM option is enabled.
(d) When the HDSL2 loop loses sync word (LOSW), a system alarm condition exists. However, since the H2TU-C-231 enters the

acquiring mode, the front-panel status LED flashes red, and the ACQ or SIG message displays instead of the ALRM message.

Table 15.

Front-Panel System Alarms Summary (Continued)

Front-Panel
Message

(a)

Alarm

Description

To Inhibit

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