EEG HD1492 Product Manual page 26

HD1492 HD Encoder Frame Card
automatically whenever the Encoder is operating.
Packets are inserted into output video signals using EEG's proprietary
Stochastic Scheduling Algorithm. The Stochastic Scheduling Algorithm
is a finely tuned solution to the Field 2 bandwidth limitations that cause
difficulties in XDS packet transmission. A Priority level is automatically
assigned to each packet based on its XDS Class and Type. The Stochastic
Scheduling Algorithm ensures both that high priority packets like V-chip
data and program names are transmitted frequently enough to be in-
stantly accessible for new viewers, and that lower priority packets are
guaranteed to be inserted periodically, and not preempted completely.
As per CEA-608B specifications, all available Field 2 space is filled,
rescheduling and regeneration are automatically performed on all up-
stream packets, and packet continuations are applied when necessary.
Additionally, upstream XDS program packets will continue to transmit
for five minutes after any non-clearing upstream interruption, such as a
commercial break or undesired outage.
Enable XDS Entry:
<CTRL+A>O XDS O <ENTER>
This command must be entered to enable a port for XDS input. A port
must be enabled for XDS input in order to accept XDS data and control
commands. The character repeated in the command is a capital o and
not a zero.
Set Active Port:
<CTRL+A>O Px XDS O <ENTER>
Used to request or yield Active status. The 'Px' argument specifies the
port that XDS activity will be set to, i.e. P1. Port P3 can set the Active
status of any port. The other ports can only request active status for
itself and so does not need to enter the Px parameter. Active status can
only be obtained if the port has been authorized in the Permission List.
Only one port can be active for each Data Type at a time. If another
port is already active the E1 error message will be returned. If the
command is entered with the override parameter O, the port entering
the command will become active in place of the previous active port.
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