Verilink HDM 2180 (880-503048-001) Product Manual - Manual (Page 72)

Troubleshooting
6-4 Verilink HDM 2180 User Manual
declared, the HDM 2180 module sends a message to the Craft
interface and Node Manager (if used), lights the appropriate LED
indicator, and trips the alarm relay (if connected). The following
error conditions must persist for at least one second for a major
alarm to be declared:
• C-bit Severely Errored Seconds (CSES)—A CSES is a second
with 44 or more CCVs or one or more Out of Frame defects or a
detected incoming AIS.
• P-bit Severely Errored Seconds (PSES)—A PSES is a second
with 44 or more PCVs or one or more Out of Frame defects or a
detected incoming AIS. This gauge is not increased when UASs
are counted.
• Local Unavailable Second (LUAS)—An unvailable second
during which the local DS3 port is unable to receive or
transmit traffic.
• Line Severely Errored Second (LSES)—A second during which
the port was (at any instance during the second) in the AIS
state.
Minor Alarms The following error conditions do not affect traffic along the DS3
line. They generate a minor alarm:
• Power Supply Missing (in redundant power supply
configurations)—This alarm indicates that one of the
redundant power supplies has failed.
• Remote Alarm Indication (RAI)—This alarm indicates that the
remote end is in a state of alarm. A Remote Alarm or Remote
Alarm Indication is the alarm a receiving channel bank or
multiplexer sends to the other end of the circuit when it
detects a Loss of Signal or Loss of Frame. There is a 2- to 3-
second integration period upon detection of LOS or LOF before
an alarm is sent to the far-end equipment. This condition is
also referred to as a Yellow Alarm.
• Alarm Indication Signal (AIS)—Using an unframed all-ones bit
pattern, an AIS alarm indicates that an alarm condition exists
upstream in a circuit leading to the downstream equipment.
This is also called an All-Ones Keep-Alive or Red Alarm Signal.
An AIS defect is declared when there are 3 or fewer zeros in
512 bit times and an LOF defect. It is cleared when there are 3
or more zeros in two frames or the LOF defect no longer exists.
• C-bit Coding Violation (CCV)—An error event that reflects the
occurrence of received CP-bit parity errors during the
accumulation interval. The CP-bits are not affected by
customer-owned equipment and are therefore more accurate
than P-bit parity.