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> Home Page > Organization > OCIO > TOC > The Gateway > The WMO > Codes & Headings > Addressed Message >FORMAT FOR THE TEXT OF ADDRESSED MESSAGESAND A GENERAL EXAMPLE OF EACH TYPEGENERAL FORMAT FORM(only alphabet 5 is shown)
The form of the abbreviated heading: T1 T2 A1 A2 ii CaCaCaCa YYGGgg
where, T1T2 = BM designator for message in alphanumeric form BI designator for addressed message in binary form (use on X.25 links only) A1A2 = type of addressed message options: AA - administrative message (to be passed to a person for information or action) BB - service message (to be passed to a person for action) RR - request for a GTS message by heading or sequence number RQ - request-to-database for data (request format TBD) intended for GDPS action DA - the returned data response to the RR or RQ addressed message ii = always 01 (no exceptions allowed) CaCaCaCa = location indicator of the center on the GTS to whom the message is addressed YYGGgg = time of insertion on the GTS CCCC = the international location indicator of the center originating the message TYPE 1 A1 A2 = AA - Administrative message The contents of this type message is a simple character free flowing text, intended for human readability. This message type should be sent to a computer display or a printer. This type text message should be about general operational and/or administrative matters or discussions and GTS coordination topics. The T1 T2 option to use is BM only, as the text is character data. Example: 345 BMAA01 EDZW 261215 EGRR ATTN OFFENBACH DATA MANAGER THE BULLETINS YOU REQUESTED WILL BE RELAY TO YOUR CENTER BEGINNING THE FIRST OF THE MONTH SMVG01 TVSV SMTD01 TTPP REGARDS, BMO DATA MANAGER SUPERVISOR= Note: EDZW is the center the message is addressed to; EGRR is the originating center of the message TYPE 2 A1A2 = BB - Service message The contents of this type message is a simple character free flowing text, intended for human readability. These message types should be sent to a display or printer. These are text messages about operational status and/or problem resolution matters. The T1 T2 option to use is BM only, as the text is character data. Example: 321 BMBB01 EGRR 281425 KWBC ATTN BRACKNELL COMMUNICATIONS SUPERVISOR THE GTS LINK BETWEEN WASHINGTON AND BRASILIA IS DOWN FOR 6 HOURS DUE TO LINE RECONFIGURATION AT BRASILIA. REGARDS, WASHINGTON COMMS SUPERVISOR= Note: EGRR is the center the message is addressed to; KWBC is the originating center of the message TYPE 3 A1A2 = RR - Request/Reply message The structure of the text for this type message has two specific classes using two different formats in the request text. This addressed message type is for use between nodes of the GTS. To use the CLASS 1 formatted request form, the nodes of the GTS must be adjacent nodes. To use the CLASS 2 formatted request form, the nodes of the GTS do not have to be adjacent to each other. The request / reply type message is for the acquisition of data at the bulletin level and the bulletin is assumed to already exist. If it is sent on an X.25 virtual channel established for the exchange of alphanumeric data, then the T1 T2 option of BM is recommended; and if, the X.25 virtual channel was established for binary data exchange, then the T1 T2 option of BI is recommended. If there is only one virtual channel between nodes for both alphanumeric and binary data exchange, it is recommended to use the T1 T2 option of BI as a default. The use of the T1 T2 option of BM would be used on all GTS links using character protocols (i.e. BAUDOT or ERROR CONTROL PROCEDURES), as all addressed messages and request / reply responses are alphanumeric.
TYPE 4 A1 A2 = RQ - Request-to-Database message The format for this type message will be in a specific format. The intent is for automatic computer processing. There is one type of request message to a data base (for GDPS use).
TYPE 5 A1A2 = DA Data message This is the returned data message type. The purpose of this heading is to insure that if the requested data message is a bulletin containing a WMO abbreviated heading, the heading of the requested message heading is not used in the routing of the response back to the requesting center. To insure proper routing the T1 T2 for either BM or BI must reflect the code type in the returning data message. The data message has four different response forms. The response can be:
There is only one bulletin or meta-data-file in a responding data message. In the examples below, assume the data massage can either be BM or BI for the CLASS 1 depending on which virtual channel. If both the alphanumeric and binary messages are transmitted on only one virtual channel the use of BI will be the default.
Note: limitation - circuits or virtual channels with priority queues must guard against confusion when selecting and responding to sequence number requests for transmission. WHERE: (CR) = Carriage Return (LF) = Line Feed (SOH) = Start of header control character (ETX) = End of text control character
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