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Paradise P300 User Manual

Page 64

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P300H

P300 Series Modem Installation and Operating Handbook

Page 64

the Rx Clock section) also source the Tx Clock as it is slaved to the Rx clock
whatever the source.

Note the P300 provides as standard the facility for Asymmetric Loop Timing (a
$1000 option from some vendors). This means you can set Tx timing =

Rx

ref(=Sat)

even if the Tx and Rx rates are different and it will generate the Tx Clock

from the incoming satellite clock. This works for any combination of rates, it
does not require the Rx rate to be higher than the Tx, or the rates to be in any way
related.

Finally, and only for those with inquisitive minds, why does it state earlier “This
option is only of any practical use when the Rx Clocking is set to

Satellite

or

Station Clock

” ? Because, with Rx=

Tx Clock In

it causes a clock loop as Rx=Tx

AND Tx=Rx, with Rx=

Internal

it is the same as selecting Tx=

Internal

, ie the

second Tx Clocking option, and with Rx=

DCE Clock

it does something entirely

different for a reason even the inquisitive would find tedious, and uses the Station
Clock again if there is one or the Internal 1PPM ref if not. So this option really is
only of any practical use when the Rx Clocking is set to

Satellite

or

Station

Clock

.