38MN002000A © 2004 Navman NZ Ltd. All rights reserved. Proprietary information and specifications subject to change without notice.Message ID: 1219Rate: as required (maximum rate is 1 Hz)Message length: 12 wordsWord No. Name Type Units Range Resolution1-4 Message header5 Header checksum6 Sequence Number (Note 1) I 0 to 32 767Altitude input control (7.0-7.15)7.0 Force use Bit 1 = force7.1 MSL select Bit 1 = MSL7.2 Store (RAM) (Note 2) Bit 1 = store7.3 Store (EEPROM) (Note 2) Bit 1 = store7.4 Clear (RAM) Bit 1 = clear7.5 Clear (EEPROM) Bit 1 = clear7.6-7.15 Reserved8-9 Altitude DI m ±0 to 50 000 10 -210 Altitude standard deviation UDI m 0 to 10 000 10 -211 Data checksumNote 1: The sequence number is a count that indicates whether the data in a particular binary message has been updated orchanged since the last message input.Note 2: For an altitude sensor that is supplying data in real-time, the OEM must ensure that bits 7.2 and 7.3 are set to zero so theattitude value will not be stored continuously in memory (RAM or EEPROM).Table 3-31 Message 1219 (user-entered altitude input)3.5.2.9 Message 1219 (user-entered altitude input).This message allows the user to enter an altitudeto be used for altitude hold during 2D navigation.If the ‘force use’ field is not set, the receiver mayignore the altitude input if it thinks it has a betterestimate.Setting the ‘clear’ field will clear out the lastestimate of altitude which the receiver uses foraltitude hold. Setting the ‘MSL select’ field allowsentry of mean-sea- level altitude. A standarddeviation can be specified to indicate theuncertainty associated with the entered altitude.The receiver will weight the altitude measurementaccording to this uncertainty. As a special case, azero standard deviation indicates that the quality ofthe altitude is not known. The contents of the ‘user-entered altitude input’ message are described inTable 3-31.
