[EAS] EAS Digest, Vol 15, Issue 19

[Harold Price]

Tom,

Good thought, but it won't work.  The problem with a converter box 
modifying the EAS message to something other than what was really 
received is duplicate detection.

The legacy box would see two different EANs, one from the converter 
box, and one  or more over the air versions.  Since the locations 
aren't the same, the two EANs would not be identified as duplicates, 
and the legacy device could air the second one as well - and would be 
required to if the second came in after the first one had already been relayed.

A further problem is if anyone is monitoring the converter/legacy 
pair - they will also see the modified alert and could air more than one EAN.

EAS won't work unless every EAS/CAP device generates exactly the same 
output EAS ZCZC string in response to a particular input CAP or EAS 
message.  (One exception, the call sign field (LLLLLLLL) is different 
for each relay, and is specifically not included in duplicate detection).

Harold

At 07:43 PM 1/20/2012, Tom Spencer wrote:
>I thought of a way that the intermediary device and a legacy device that
>can't be updated to include the "000000" location code.
>...
>
>What this would do is substitute the code that the legacy box will
>recognize as being something it should take care of for the national code.