
XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.1
On the other hand, the payload portion of a framed AIS pattern is all ones. However, a framed AIS pattern still
has correct framing bits. Therefore, the equipment further down the line can still maintain frame synchroniza-
tion as well as timing synchronization. In this case, no LOF or Red alarm will be declared.
"AIS16" is an AIS alarm that is supported only in E1 framing format. It is an all ones pattern in time slot 16 of
each E1 frame. As we mentioned before, time slot 16 is usually used for signaling and data link in E1, there-
fore, an "AIS16" alarm is transmitted by the intermediate node to indicate that the data link channel is having a
problem. Since all the other thirty one time slots are still transmitting normal data (that is, framing information
and PCM data), the equipment further down the line can still maintain frame synchronization, timing synchroni-
zation as well as receive PCM data. In this case, no LOF or Red alarm will be declared by the equipment fur-
ther down the line. However, a CAS Multi-frame Yellow Alarm will be sent by the equipment further down the
line to indicate the loss of CAS Multi-frame alignment.
The Transmit Alarm Indication Signal Select bits of the Alarm Generation Register (AGR) enable the three
types of AIS transmission that are supported by the XRT86L30 framer. The table below shows configurations
of the Transmit Alarm Indication Signal Select bits of the Alarm Generation Register (AGR).
PRELIMINARY
241
12.5.2 How to configure the framer to generate Red Alarm
Upon detection of Loss of Signal (LOS) or Loss of Frame (LOF) condition, the Repeater will generate an inter-
nal Red Alarm when enabled. This alarm will normally trigger a microprocessor interrupt informing the user that
an incoming signal failure is happening.
The Loss of Frame Declaration Enable bit of the Alarm Generation Register (AGR) enable the generation of
Red Alarm. The table below shows configurations of the of Frame Declaration Enable bit of the Alarm Genera-
tion Register (AGR).
12.5.3 How to configure the framer to transmit Yellow Alarm
The XRT86L30 framer supports transmission of both Yellow Alarm and CAS Multi-frame Yellow Alarm in E1
mode.
ALARM GENERATION REGISTER (AGR) (ADDRESS = 0X0108H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
3-2
Transmit AIS Select
R/W
These READ/WRITE bit-fields allows the user to choose which one of the three
AIS pattern supported by the XRT86L30 framer will be transmitted.
00 - No AIS alarm is generated.
01 - Enable unframed AIS alarm of all ones pattern.
11 - AIS16 pattern is generated. Only time slot 16 is carrying the all ones pattern.
The other time slots still carry framing and PCM data.
11 - Enable framed AIS alarm of all ones pattern except for framing bits.
ALARM GENERATION REGISTER (AGR) (ADDRESS = 0X0108H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
6
Loss of Frame Dec-
laration Enable
R/W
This READ/WRITE bit-field permits the framer to declare Red Alarm in case of
Loss of Frame Alignment (LOF).
When receiver module of the framer detects Loss of Frame Alignment in the
incoming data stream, it will generate a Red Alarm. The framer will also generate
an RxLOFs interrupt to notify the microprocessor that an LOF condition is
occurred. A Yellow Alarm is then returned to the remote transmitter to report that
the local receiver detects LOF.
0 - Red Alarm declaration is disabled.
1 - Red Alarm declaration is enabled.