P300H
P300 Series Modem Installation and Operating Handbook
Page 105
6.10.3 Change, User-Opt, Operation, ACTIONS Menu
Actions: 1:Buffer auto centre
2:BER 3:AIS 4:Back Alarm
Change, User-Opt, Operation, Actions Menu
ÞËÚÚÛÎ
ßËÌÑÝÛÒÌÎÛ
This selects if the receive buffer is automatically centred when the Rx traffic
returns to OK from the fail state. This takes advantage of any outage, and
ensures the buffer is centred every time normal operation begins. This option
can be disabled, as for minor outages the errors or sync losses caused by
centering the buffer may be larger than those caused by the outage itself.
Default:
ÛÒßÞÔÛÜ
ÞÛÎ ßÝÌ×ÑÒ
This option controls how a high BER indication is handled. INTELSAT specify
that when the BER exceeds 1 x 10
-3
the following actions are required: the Rx
prompt alarm should be raised, AIS should be forced, and the backward alarm
sent. This option can disable the forcing of AIS and the backward alarm to
maintain the traffic as best as possible.
Note
the Rx Prompt alarm
is
still raised
even if this option is set to
ÒÑ ßÝÌ×ÑÒ
to disable the AIS and Backward
Alarm.
Default:
ßÝÌ×ÑÒ
ß×Í ßÝÌ×ÑÒ
This option is similar to BER action above, except it specifies how the modem
is to handle the detection of AIS (the Alarm Indication Signal, all ones).
INTELSAT specify the required actions as: the Prompt Traffic alarm should be
raised, AIS should be regenerated (to prevent multiple noisy links building up
enough errors to stop the all ones being detected), and the backward alarm
should be sent. In continuous modes this option allows all three actions to be
disabled. In Drop/Insert modes the Prompt Traffic alarm and the backward
alarm are disabled, but AIS is still regenerated if it is detected.
Default:
ßÝÌ×ÑÒ
ÞßÝÕùßÔßÎÓ
This option is only displayed if the Insert mux is active and set for Channel
Associated Signalling (CAS). It controls the forcing of the `abcd` signalling bits
passed to the terrestrial port to certain values when an incoming backward
alarm is received.
Default:
Ò±®³¿´
. The options are
Ò±®³¿´
A backward alarm is sent out of the insert mux to the terrestrial
network (INTELSAT IESS 309).
Í·¹ ß×Í
The `abcd` signalling nibbles for the
inserted timeslots
are
forced to all ones.
¾ãï
The `b` bit of the `abcd` signalling nibbles for the
inserted
timeslots
are forced to a one (Eutelsat EESS 501, SMS).
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The `a` and `b` bits of the `abcd` signalling nibbles for the
inserted timeslots
are forced to a one.
6.10.4 Change, User-Opt, Operation, TERRESTRIAL Menu
Terrestrial: 1:PCM Bearer CRC
BER monitors: 2:Tx/Drop mux 3:Insert mux
Change, User-Opt, Operation, Terrestrial Menu
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This option is only applicable when the unit is configured for Drop/Insert