ADC H4TU-C-319 List 1 Line Unit Manuel D’Utilisation

To improve HDSL4 compatibility with the switch-to-protect features used in DLC feeder applications, the 
H4TU-C-319 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

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.