P300H
P300 Modem Installation and Operating Handbook
Page 85
Insert bearer : [?]
1=Loop Terr 2=Generate internally
Change, Rx, Baseband, Insert Mux, Bearer Route Menu
Is all Rx data for this destination: [?]
1=All 2:Partial
Change, Rx, Baseband, Insert Mux, Partial Insert Menu
6.7.1
Change, Rx, SERVICE Menu
See "Change, Tx/Rx, Service Menu" on page 52
6.7.2
Change, Rx, BASEBAND Menu
The
Continuous
&
Other
menu options are identical to the Tx selections, see "Change, Tx/Rx, Baseband
Menu" on page 55
The
Insert Mux
selection is the same as the
Drop Mux
selection except the prior to the same dialogue as
on the Tx path two other questions are asked: Bearer routing (
Loop Terr
or
Generate
) & Partial Insert (
All
or
Partial
). These are described as follows:
Bearer Routing
The bearer to the Insert Mux can either be looped from the Drop Mux, or generated internally. The following
prompt is displayed:
In most situations
Loop Terr
is selected, and the receive data is inserted onto the same bearer from which
the Tx data was dropped. This however forces the receive data to be passed to the terrestrial using the
terrestrial clock (which is already clocking the bearer) and hence is the `normal` plesiochronous mode. For
other clock modes, such as where it is necessary to use the satellite clock or a station clock to drive the
clock to the terrestrial equipment, use
Generate internally
.
LOOP TERR
The PCM bearer at the input to the Drop Mux is looped to the Insert Mux. If this
bearer should fail (no clock or AIS) the modem will switch
temporarily
to
Generate Internally
so that the Rx traffic is not lost as a result of a Tx fault.
When set for
Loop Terr
the Rx Clocking menu asks for the selection of the clock
source for the
Backup bearer
(Satellite, Internal, or Station clock).
GENERATE
The modem generates a suitable formatted PCM bearer internally with
multiframes (G.732 CAS) and CRC's (T1-ESF & G.732) as it is set to utilise (ie
it will not generate a terrestrial TS16 CAS multiframe unless it is operating in a
CAS mode and therefore expects one). When so configured the Rx Clocking
menu asks for the selection of the clock from which to source the
Generated
bearer
(Satellite,
Tx Clock In
, Internal, or Station clock).
Partial Insert
This option only available if the Extended D/I feature if available (standard on P300-TCM) and is provided
to simplify Multidestinational working. It allows
some
of the incoming Rx data to be inserted onto the insert
bearer, and the information for other destinations to be discarded. This screen is only displayed if Rx=Tx
is
Off
, when Rx=Tx is
On
(ie a symmetrical link, which is by definition unlikely to be multi-destinational)
Partial Insert makes no sense, and the option is not displayed.
See the applications section, para 8.3 "Partial Insert and Multidestinational Working" on page 133 for a
discussion of this facility.
If
All
is selected, the dialogue continues as with the Drop Mux on the Tx path.
