FALC
56
PEF 2256 H/E
Functional Description T1/J1
User’s Manual
Hardware Description
155
DS1.1, 2003-10-23
5.3
Additional Receive Framer Functions (T1/J1)
5.3.1
Error Performance Monitoring and Alarm Handling
Alarm Indication Signal: Detection and recovery is flagged by bit FRS0.AIS and
ISR2.AIS. Transmission is enabled by bit FMR1.XAIS.
Loss-Of-Signal: Detection and recovery is flagged by bit FRS0.LOS and ISR2.LOS.
Remote Alarm Indication: Detection and release is flagged by bit FRS0.RRA and
ISR2.RA/RAR. Transmission is enabled by bit FMR4.XRA.
Excessive Zeros: Detection is flagged by bit FRS1.EXZD.
Pulse-Density Violation: Detection is flagged by bit FRS1.PDEN and ISR0.PDEN.
Transmit Line Shorted: Detection and release is flagged by bit FRS1.XLS and
ISR1.XLSC.
Transmit Ones-Density: Detection and release is flagged by bit FRS1.XLO and
ISR1.XLSC.
Table 39
Alarm
Red Alarm or
Loss-Of-Signal
(LOS)
Summary of Alarm Detection and Release (T1/J1)
Detection Condition
no transitions (logical zeros) in a
programmable time interval of 16
to 4096 consecutive pulse
periods. Programmable receive
input signal threshold
Clear Condition
programmable number of ones (1
to 256) in a programmable time
interval of 16 to 4096 consecutive
pulse periods. A one is a signal
with a level above the
programmed threshold.
or
the pulse-density is fulfilled and no
more than 15 contiguous zeros
during the recovery interval are
detected.
active for at least one multiframe.
FMR4.AIS3 = 0:
more than 2 zeros in 12 or 24
frames (ESF),
Blue Alarm or
Alarm Indication
Signal (AIS)
FMR4.AIS3 = 0:
less than 3 zeros in 12 frames or
24 frames (ESF),
FMR4.AIS3 = 1:
less than 4 zeros in 12 frames or
less than 6 zeros in 24 frames
(ESF)
FMR4.AIS3 = 1:
more than 3 zeros in 12 frames or
more than 5 zeros in 24 frames
(ESF)