Sec. 11.31  EAS protocol.

    (a) The EAS uses a four part message for an emergency activation of 
the EAS. The four parts are: Preamble and EAS Header Codes; audio 
Attention Signal; message; and, Preamble and EAS End Of Message (EOM) 
Codes.
    (1) The Preamble and EAS Codes must use Audio Frequency Shift Keying 
at a rate of 520.83 bits per second to transmit the codes. Mark 
frequency is 2083.3 Hz and space frequency is 1562.5 Hz. Mark and space 
time must be 1.92 milliseconds. Characters are ASCII seven bit 
characters as defined in ANSI X3.4-1977 ending with an eighth null bit 
(either 0 or 1) to constitute a full eight-bit byte.
    (2) The Attention Signal must be made up of the fundamental 
frequencies of 853 and 960 Hz. The two tones must be transmitted 
simultaneously. The Attention Signal must be transmitted after the EAS 
header codes.
    (3) The message may be audio, video or text.
    (b) The ASCII dash and plus symbols are required and may not be used 
for any other purpose. Unused characters must be ASCII space characters. 
FM or TV call signs must use a backslash ASCII character number 47 (/) 
in lieu of a dash.
    (c) The EAS protocol, including any codes, must not be amended, 
extended or abridged without FCC authorization. The EAS protocol and 
message format are specified in the following representation. Examples 
are also provided in the EAS Operating Handbook.

[PREAMBLE] ZCZC - ORG - EEE - PSSCCC + TTTT - JJJHHMM - LLLLLLLL -
(one second pause)
[PREAMBLE] ZCZC - ORG - EEE - PSSCCC + TTTT - JJJHHMM - LLLLLLLL -
(one second pause)
[PREAMBLE] ZCZC - ORG - EEE - PSSCCC + TTTT - JJJHHMM - LLLLLLLL -
(at lease a one second pause)
(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 asynchoronous 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.

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EEE-  This is the Event code and indicates the nature of the EAS 
activation. The codes are specified in paragrah (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 System 
(FIPS) numbers as described by the U.S. Department of Commerce in 
National Institute of Standards and Technology publication 772. Each 
state is assigned an SS number as specified in paragraph (f) of this 
section. Each county is 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 Central, 3 = Northeast, 4 = West Central, 5 = Central, 6 = East 
Central, 7 = Southwest, 8 = South Central, 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 Calender 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 call sign or other identification of the 
broadcast station, or NWS office 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.
    (d) The only originator codes are:

                                                                        
------------------------------------------------------------------------
                  Originator                            ORG code        
------------------------------------------------------------------------
Broadcast station or cable system.............  EAS                     
Civil authorities.............................  CIV                     
Emergency Action Notification Network.........  EAN                     
National Weather Service......................  WXR                     
Primary Entry Point System....................  PEP                     
------------------------------------------------------------------------

    (e) The following Event (EEE) codes are presently authorized:

                                                                        
------------------------------------------------------------------------
             Nature of activation                      Event codes      
------------------------------------------------------------------------
National Codes:                                                         
  Emergency Action Notification (National       EAN                     
   only).                                                               
  Emergency Action Termination (National only)  EAT                     
  National Information Center.................  NIC                     
  National Periodic Test......................  NPT                     
  Required Monthly Test.......................  RMT                     
  Required Weekly Test........................  RWT                     
Local Codes:                                                            
    Administrative Message....................  ADR                     
    Blizzard Warning..........................  BZW                     
    Civil Emergency Message...................  CEM                     
    Evacuation Immediate......................  EVI                     
    Flash Flood Statement.....................  FFS                     
    Flash Flood Warning.......................  FFW                     
    Flash Food Watch..........................  FFA                     
    Flood Statement...........................  FLS                     
    Flood Warning.............................  FLW                     
    Flood Watch...............................  FLA                     
    High Wind Warning.........................  HWW                     
    High Wind Watch...........................  HWA                     
    Hurricane Statement.......................  HLS                     
    Hurricane Warning.........................  HUW                     
    Hurricane Watch...........................  HUA                     
    Practice/Demo Warning.....................  DMO                     
  Severe Thunderstorm Warning.................  SVR                     
  Severe Thunderstorm Watch...................  SVA                     
  Severe Weather Statement....................  SVS                     
  Special Weather Statement...................  SPS                     
  Tornado Warning.............................  TOR                     
  Tornado Watch...............................  TOA                     
  Tsunami Warning.............................  TSW                     
  Tsunami Watch...............................  TSA                     
  Winter Storm Warning........................  WSW                     
  Winter Storm Watch..........................  WSA                     
------------------------------------------------------------------------

    (f) The State and Territory FIPS number codes (SS) are as follows. 
County FIPS numbers (CCC) are contained in the State EAS Mapbook.

                                                                        
------------------------------------------------------------------------
                             State                               FIPS  
------------------------------------------------------------------------
AL............................................................        01
AK............................................................        02
AZ............................................................        04
AR............................................................        05
CA............................................................        06
CO............................................................        08
CT............................................................        09
DE............................................................        10
FL............................................................        12
GA............................................................        13
HI............................................................        15
ID............................................................        16
IL............................................................        17
IN............................................................        18
IA............................................................        19
KS............................................................        20
KY............................................................        21
LA............................................................        22
ME............................................................        23
MD............................................................        24
MA............................................................        25
MI............................................................        26
MN............................................................        27
MS............................................................        28
MO............................................................        29
MT............................................................        30
NE............................................................        31
NV............................................................        32
NH............................................................        33
NJ............................................................        34

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NM............................................................        35
NY............................................................        36
NC............................................................        37
ND............................................................        38
OH............................................................        39
OK............................................................        40
OR............................................................        41
PA............................................................        42
RI............................................................        44
SC............................................................        45
SD............................................................        46
TN............................................................        47
TX............................................................        48
UT............................................................        49
VT............................................................        50
VA............................................................        51
WA............................................................        53
WV............................................................        54
WI............................................................        55
WY............................................................        56
------------------------------------------------------------------------

District of Columbia--11

                                                                        
------------------------------------------------------------------------
                             Terr.                               FIPS  
------------------------------------------------------------------------
AS............................................................        60
PR............................................................        72
FM............................................................        64
PW............................................................        70
GU............................................................        66
UM............................................................        74
MH............................................................        68
VI............................................................        78
MP............................................................        
------------------------------------------------------------------------

[59 69 FR 67092 , Dec. 28, 1994, as amended at  60 FR 55999 , Nov. 6, 1995;  61 FR 54952 , Oct. 23, 1996]