Q-Flex Satellite Modem Installation and Operating Handbook
13-5
•
IBS Aux mode.
This controls the operating mode of the Aux channel, controlling
the allocation of overhead between the Aux and ESC interfaces. The Aux channel
can be set to
Off
,
Intelsat over-sampled
or
Synchronous.
•
Enable backward alarm
. This controls whether a backward alarm facility is
supported as part of the ESC channel.
•
ESC interface type.
This specifies which of the modem’s physical interfaces is to
be connected through to the satellite ESC channel. This is described under the
Edit->Tx-Rx>Framing->Overhead Closed
screen description.
•
Aux interface type.
This specifies the Aux electrical interface. The relevant
physical interface (on the shared Async ESC/Aux port on the base modem or the
separate Aux port on the IDR card) is directly connected through to the ESC
channel. This interface on the modem provides the IBS low-rate Intelsat
oversampled ESC facility. The ESC and Aux functions are mutually exclusive
unless an IDR card is fitted. If an IDR card is fitted then the Aux port can provide
32kbps or 64kbps access to the IDR overhead in place of one or both of the IDR
32kbps ADPCM audio ESC channels, or it can provide either the IBS low-rate
Intelsat oversampled ESC facility or a higher rate synchronous channel within the
IBS overhead.
13.4 Edit->Tx-Rx>Framing->Overhead IDR Screen
The
Edit->Tx-Rx->Framing->Overhead IDR
screen, shown in
Figure 13-4
controls the
overhead in IDR mode, allowing the IDR 8kbps ESC channel and audio channels to be
set up and the routing of multiple backward alarms. It also allows Aux data to be allocated
in place of one or both of the IDR audio channels if these are not used or it can be used
to reduce the standard 96kbps overhead to 64kbps or 32kbps.
Figure 13-4 Edit->Tx-Rx->Framing->Overhead IDR Screen