6.7.1Change, Rx, SERVICE Menu

See "Change, Tx/Rx, Service Menu" on page 54

6.7.2Change, Rx, BASEBAND Menu

The Continuous & Other menu options are identical to the Tx selections, see "Change, Tx/Rx, Baseband Menu" on page 57

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:

Insert bearer : [?]

1=Loop Terr 2=Generate internally

Change, Rx, Baseband, Insert Mux, Bearer Route Menu

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.

Is all Rx data for this destination: [?]

1=All 2:Partial

Change, Rx, Baseband, Insert Mux, Partial Insert Menu

See the applications section, para 8.3 "Partial Insert and Multidestinational Working" on page 143 for a discussion of this facility.

If All is selected, the dialogue continues as with the Drop Mux on the Tx path.

P300H

P300 Series Modem Installation and Operating Handbook

Page 87

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Paradise P300 specifications Change, Rx, Service Menu, Change, Rx, Baseband Menu, Bearer Routing, Partial Insert