
FALC
56
PEF 2256 H/E
Functional Description T1/J1
User’s Manual
Hardware Description
156
DS1.1, 2003-10-23
5.3.2
Auto Modes
Automatic remote alarm (Yellow Alarm) access
If the receiver has lost its synchronization (FRS0.LFA) a remote alarm (yellow alarm)
is sent to the distant end automatically, if enabled by bit FMR2.AXRA. In synchronous
state the remote alarm bit is removed.
Automatic AIS to system interface
In asynchronous state the synchronizer enforces an AIS to the receive system
Yellow Alarm or
Remote Alarm
(RRA)
1)
RC1.RRAM = 0:
bit 2 = 0 in 255 consecutive time
slots or
FS-bit = 1 of frame12 in F12 (D4)
format or
8
×
1,8
×
0 in the DL channel
(ESF)
RC1.RRAM = 1:
bit 2 = 0 in every time slot per
frame or
FS-bit = 1 of frame12 in F12 (D4)
format or
8
×
1,8
×
0 in the DL channel
(ESF)
more than 7 (B8ZS code) or
more than 15 (AMI code)
contiguous zeros
less than N ones in each and
every time window of 8
×
(N+1)
time slots with N taking all values
of 1 to 23
or
more than 15 consecutive zeros
more than 3 pulse periods with
highly increased transmit line
current on XL1/2
32 consecutive zeros in the
transmit data stream on XL1/2
RC1.RRAM = 0:
set conditions no longer detected.
RC1.RRAM = 1:
bit 2 = 0 not detected in 3
consecutive frames or
FS-bit not detected in 3
consecutive multiframes or
8
×
1,8
×
0 not detected for 3 times
in a row (ESF).
Excessive Zeros
(EXZD)
Latched Status: cleared on read
Pulse-Density
Violation
(PDEN)
Latched Status: cleared on read
Transmit Line
Short
(XLS)
Transmit
Ones-Density
(XLO)
RRA detection operates in the presence of 10
-3
bit error rate.
transmit line current limiter
inactive
Cleared with each transmitted
pulse
1)
Table 39
Alarm
Summary of Alarm Detection and Release (T1/J1)
(cont’d)
Detection Condition
Clear Condition