Specifications

On-Line Operation
6-19
Press the Escape button two times to return to the Status submenu.
Alarms
The Excalibur Multirate DAP reports a variety of alarm conditions to alert you to
problems in the network. You can configure the DAP to sound a beeper and/or light the
User LED when an alarm is reported. The alarm message is displayed on the LCD
screen.
The following conditions cause an alarm to be reported:
• External Alarm - caused by the occurrence of a customer defined external event
that is sensed by the DAP. The event that triggers this alarm is programmable to
active high or active low.
• Out of Service - indicates failures within the higher order facilities of the DDS
network. This alarm is transmitted after the unit receives Out of Service
sequences from the DDS network for at least 1 second. Refer to AT&T
Publication 62310 for a description of Out of Service. This alarm is usually
generated to the CMS system by a central unit since any remote unit may not be
able to transmit through the network.
• DTE Change of State - occurs when the DTE interface has an invalid signal level
(indicating loss of power to the DTE) or the signal level at the DTE interface
regains a valid level (indicating power has been restored to the DTE). The DTE
Transmit Data signal is monitored to determine if an alarm condition exists.
• Service Loop - generated when a Network Service Loop condition is initiated or
terminated. Service Loops are used by the service provider to test the line from
the central office to the central or remote units. This alarm informs the upstream
device when the unit goes into a line loopback and when the test is terminated.
During the test, communication with downstream devices is not possible since
the network is not available. Therefore, this alarm should only be received from
a central unit.
• Transmit Loop Fault - generated by the DAP if the far-end unit is not
transmitting properly. This alarm is only available when the service is set for
DDS-SC.
• Receive Loop Fault - generated by the DAP if it is not receiving a signal or the
correct framing pattern from the network due to local loop (DDS to User) or
network failure, or if it is detecting unknown control codes from the network.
This alarm is sent when any of these conditions is detected for at least 1 second.