One-Net/DASDEC User Manual
A-7
v3.0 | r1016
(Transmission of 8 to 25 seconds of Attention Signal)
(Transmission of audio, video or text messages)
(at least a one second pause)
[PREAMBLE]NNNN
(One second pause) [PREAMBLE]NNNN
(One second pause) [PREAMBLE]NNNN
(At least one second pause)
____________________________________________________________
[PREAMBLE]
This is a consecutive string of bits (sixteen bytes of AB hexadecimal [8
bit byte 10101011]) sent to clear the system, set AGC and set asynchronous decoder
clocking cycles. The preamble must be transmitted before each header and End Of
Message code.
ZCZC
- This is the identifier, sent as ASCII characters ZCZC to indicate the start of ASCII
code.
ORG
- This is the Originator code and indicates who originally initiated the activation of
the EAS. These codes are specified in paragraph (d) of this section.
EEE
- This is the Event code and indicates the nature of the EAS activation. The codes
are specified in paragraph (e) of this section. The Event codes must be compatible with
the codes used by the NWS Weather Radio Specific Area Message Encoder (WRSAME).
PSSCCC
- This is the Location code and indicates the geographic area affected by the
EAS alert. There may be 31 Location codes in an EAS alert. The Location code uses
the Federal Information Processing Standard (FIPS) numbers as described by the
U.S. Department of Commerce in National Institute of Standards and Technology
publication FIPS PUB 6-4. Each state is assigned an SS number as specified in para
-
graph (f) of this section. Each county and some cities are assigned a CCC number. A
CCC number of 000 refers to an entire State or Territory. P defines county subdivisions
as follows: 0 = all or an unspecified portion of a county, 1 = Northwest, 2 = North, 3
= Northeast, 4 = West, 5 = Central, 6 = East, 7 = Southwest, 8 = South, 9 = Southeast.
Other numbers may be designated later for special applications. The use of county
subdivisions will probably be rare and generally for oddly shaped or unusually large
counties. Any subdivisions must be defined and agreed to by the local officials prior to
use.
+TTTT
- This indicates the valid time period of a message in 15 minute segments up to
one hour and then in 30 minute segments beyond one hour; i.e., +0015, +0030, +0045,
+0100, +0430 and +0600.
JJJHHMM
- This is the day in Julian Calendar days (JJJ) of the year and the time in hours
and minutes (HHMM) when the message was initially released by the originator using
24 hour Universal Coordinated Time (UTC).
LLLLLLLL
- This is the identification of the broadcast station, cable system, MDS/MMDS/
ITFS station, NWS office, etc., transmitting or retransmitting the message. These codes
will be automatically affixed to all outgoing messages by the EAS encoder.
NNNN
- This is the End of Message (EOM) code sent as a string of four ASCII N
characters.
