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15.2
Best Practices to Avoid Key Loss
ATSC off air signals in the RF system can cause Pro:Idiom key loss if not mapped correctly.
When a TV switches from an off air channel to a Pro:Idiom channel the tuner may try and sent
the second audio programing (SAP) PIDS to the Pro:Idiom decryption circuits. This may cause
the TV to loss it’s Pro:Idiom keys.
Broadcast off air (OA) channels
MUST NOT
be placed adjacent to P:I protected channels
in the channel map. It does not matter where the physical channels are located, only whether
they are mapped to adjacent channels in the TV lineup.
A non-P:I, non-off air channel
MUST
be placed in the channel map between any broadcast
channel and a Pro:Idiom protected channel.
The COM2000 EPG, Home Screen or locally inserted channels makes a good buffer.
Analog SMATV channels can also be used as buffers.
Channel map in Figure 81 below show improper mapping of channels with off air and
Pro:Idiom programming on adjacent channels
Figure 81- Improper mapping of off air channels