§ 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 + TTTTpJJJHHMM-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 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 codes described in the American National Standards
   Institute   (ANSI)   standard,   ANSI   INCITS  31-2009  (“Information
   technology—Codes for the Identification of Counties and Equivalent Areas of
   the United States, Puerto Rico, and the Insular Areas”). 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.
   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 All U.S., State, Territory and Offshore (Marine Area) ANSI number
   codes (SS) are as follows. County ANSI numbers (CCC) are contained in the
   State EAS Mapbook.
       ANSI No.
   All U.S. 00
   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;  77 FR 16701 , Mar. 22, 2012;  80 FR 37174 , June 30, 2015]

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