DESCRIZIONE
Method for sending the value of a status variable between an alarm sender system comprising a sending device (100) and an alarm receiver system comprising a receiving device (201) as a part of a standardized binary coded radio message within a distributed communication system of AIS (Automatic Identification System) type according to a particular messaging standard for such a distributed messaging system, which message comprises fields for a certain predetermined information to be sent with the message, as well as a buffer field which according to the said standard is not intended to carry information, comprising the steps ofcausing the sending device to assemble, calculate a check-sum for, digitally store and transmit a certain predetermined type of message in the form of a radio signal (120) which is readable for the receiver, andcausing the receiving device to receive and interpret the thus transmitted message.
The invention is characterised in that the status variable is not related to the predetermined information but to the detection of a physical event of a particular type, detected by the alarm sender system, in that the sending device, before the checksum is calculated, inserts the value of the status variable in binary coded format into the message in a buffer field, which according to the said standard is not intended to trans-mit information, and in that the receiving device interprets the binary value as the value of the status variable.
The invention also relates to an alarm sender system and to a corresponding alarm receiver system.