Goto Section: 11.21 | 11.32 | Table of Contents

FCC 11.31
Revised as of October 1, 2011
Goto Year:2010 | 2012
  §  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 slash 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 provided in FCC Public Notices.

   [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 least 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 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 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 paragraph (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 EAS Participant, 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.

   (d) The only originator codes are:
           Originator         ORG code
   EAS Participant            EAS
   Civil authorities          CIV
   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 (Required):
   Emergency Action Notification (National only) EAN
   Emergency Action Termination (National only)  EAT
   National Information Center                   NIC
   National Periodic Test                        NPT
   Required Monthly Test                         RMT
   Required Weekly Test                          RWT
   State and Local Codes (Optional):
   Administrative Message                        ADR
   Avalanche Warning                             AVW^1
   Avalanche Watch                               AVA^1
   Blizzard Warning                              BZW
   Child Abduction Emergency                     CAE^1
   Civil Danger Warning                          CDW^1
   Civil Emergency Message                       CEM
   Coastal Flood Warning                         CFW^1
   Coastal Flood Watch                           CFA^1
   Dust Storm Warning                            DSW^1
   Earthquake Warning                            EQW^1
   Evacuation Immediate                          EVI
   Fire Warning                                  FRW^1
   Flash Flood Warning                           FFW
   Flash Flood Watch                             FFA
   Flash Flood Statement                         FFS
   Flood Warning                                 FLW
   Flood Watch                                   FLA
   Flood Statement                               FLS
   Hazardous Materials Warning                   HMW^1
   High Wind Warning                             HWW
   High Wind Watch                               HWA
   Hurricane Warning                             HUW
   Hurricane Watch                               HUA
   Hurricane Statement                           HLS
   Law Enforcement Warning                       LEW^1
   Local Area Emergency                          LAE^1
   Network Message Notification                  NMN^1
   911 Telephone Outage Emergency                TOE^1
   Nuclear Power Plant Warning                   NUW^1
   Practice/Demo Warning                         DMO
   Radiological Hazard Warning                   RHW^1
   Severe Thunderstorm Warning                   SVR
   Severe Thunderstorm Watch                     SVA
   Severe Weather Statement                      SVS
   Shelter in Place Warning                      SPW^1
   Special Marine Warning                        SMW^1
   Special Weather Statement                     SPS
   Tornado Warning                               TOR
   Tornado Watch                                 TOA
   Tropical Storm Warning                        TRW^1
   Tropical Storm Watch                          TRA^1
   Tsunami Warning                               TSW
   Tsunami Watch                                 TSA
   Volcano Warning                               VOW^1
   Winter Storm Warning                          WSW
   Winter Storm Watch                            WSA

   ^1Effective May 16, 2002, analog radio and television broadcast
   stations, analog cable systems and wireless cable systems may upgrade
   their existing EAS equipment to add these event codes on a voluntary
   basis until the equipment is replaced. All models of EAS equipment
   manufactured after August 1, 2003 must be capable of receiving and
   transmitting these event codes. EAS Participants that install or
   replace their EAS equipment after February 1, 2004 must install
   equipment that is capable of receiving and transmitting these event
   codes.

   (f) The State, Territory and Offshore (Marine Area) FIPS number codes
   (SS) are as follows. County FIPS numbers (CCC) are contained in the
   State EAS Mapbook.
      FIPS#
   State:
   AL 01
   AK 02
   AZ 04
   AR 05
   CA 06
   CO 08
   CT 09
   DE 10
   DC 11
   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
   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
   Terr.:
   AS 60
   FM 64
   GU 66
   MH 68
   MH 68
   PR 72
   PW 70
   UM 74
   VI 78
   Offshore (Marine Areas)^1:
   Eastern North Pacific Ocean, and along U.S. West Coast from Canadian
   border to Mexican border 57
   North Pacific Ocean near Alaska, and along Alaska coastline, including
   the Bering Sea and the Gulf of Alaska 58
   Central Pacific Ocean, including Hawaiian waters 59
   South Central Pacific Ocean, including American Samoa waters 61
   Western Pacific Ocean, including Mariana Island waters 65
   Western North Atlantic Ocean, and along U.S. East Coast, from Canadian
   border south to Currituck Beach Light, N.C 73
   Western North Atlantic Ocean, and along U.S. East Coast, south of
   Currituck Beach Light, N.C., following the coastline into Gulf of
   Mexico to Bonita Beach, FL., including the Caribbean 75
   Gulf of Mexico, and along the U.S. Gulf Coast from the Mexican border
   to Bonita Beach, FL 77
   Lake Superior 91
   Lake Michigan 92
   Lake Huron 93
   Lake St. Clair 94
   Lake Erie 96
   Lake Ontario 97
   St. Lawrence River above St. Regis 98

   ^1Effective May 16, 2002, analog radio and television broadcast
   stations, analog cable systems and wireless cable systems may upgrade
   their existing EAS equipment to add these marine area location codes on
   a voluntary basis until the equipment is replaced. All models of EAS
   equipment manufactured after August 1, 2003, must be capable of
   receiving and transmitting these marine area location codes. EAS
   Participants that install or replace their EAS equipment after February
   1, 2004, must install equipment that is capable of receiving and
   transmitting these location codes.

   [ 59 FR 67092 , Dec. 28, 1994, as amended at  60 FR 55999 , Nov. 6, 1995;
    61 FR 54952 , Oct. 23, 1996;  63 FR 29663 , June 1, 1998;  67 FR 18508 ,
   Apr. 16, 2002;  67 FR 77174 , Dec. 17, 2002;  69 FR 72031 , Dec. 10, 2004;
    70 FR 71033 , Nov. 25, 2005]


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Goto Year: 2010 | 2012
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