ITEM-IN-MESSAGE FORMAT 21 Feb 12 -------------------------------------------------------------------- WB4APR 21 Feb 12 updated to mention the new MESSAGE OBJECT function 30 Oct 08 added options for Sending and Reading-the-mail 07 Oct 08 updated The original ITEM-in-MSG format was designed to provide a mechanism for a station in message contact with someone anywhere in the APRS system to be able to exchange position data, not only of his own station, but also of any objects he would like the other station to see. For example. This would be used by the AVRS engine to send FREQUENCY OBJECT to a called station to have him QSY to receive the voice call. See http://aprs.org/avrs.html Do not confuse this with the MESSAGE OBJECT function which is a backwards compatible way for any existing radio to be used to send a MESSAGE OBJECT to a special OBJECT server where it is converted to an object on the APRS-IS. See http://aprs.org/aprs12/msg-obj.txt The format for ITEM-in MSG is simply an ITEM format inserted in the message text field.. The ITEM format is defined as: )NAME!DDMM.mmN/DDDMM.mmW$text..... * Where the first character is the ")" * Then a variable length object name (up to 9 bytes) * Then the usual FIXED position format beginning with a ! and followed by LAT/LONG and SYMBOL * Text is the variable length field which may contain any of the other APRS formatted data: CSE/SPD data CCC/SSS/ PHG data PHGphgd FREQUENCY FFF.FFFMHz DF data CSE/SPD/BRG/NRQ etc other any other valid fields in a position report ACKS: The ITEM-IN-MESSAGE message is transmitted like any other message including a message line number on the end. Similarly it is acked like any other message. If the ITEM is intended for a local or APRS-IS wider audience, then the ITEM might be sent to a generic callsign so that it is not acked but allowed to retry the typical 5 times to improve the reliability of receipt by all parties. DISPLAY: On receipt, if the message contains the above ITEM format, then the ITEM and position information is copied to the STATION/ OBJECT list and displayed on the map. RETENTION: If the client can edit and send its own objects from the STATION list, then it is OK to not retain a copy of the incoming ITEM-in-MSG where it will just take up room. On the other hand, if the client is unable to originate objects, then a copy of the incoming ITEM-in-MSG should be retained in the MESSAGE list for future editing. SENDER's CALLSIGN: The callsign of the sender should always be retained and displayed associated with this ITEM/OBJECT just like any other object. SEND OPTION: Another option is in the MESSAGE MENU. There can be a menu item there to allow the sending station to select any object or station in his station list, and (after editing) send it as an ITEM-in-MSG to another party. READING-THE-MAIL: Another option is on receipt. Even if a message is not to this station, if an ITEM-IN-MSG format is detected while monitoring the channel, such an ITEM should be considered general positional info and should be captured and plotted on the map. Bob, WB4APR