Navman 12 GPS Receiver User Manual


 
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MN002000A © 2004 Navman NZ Ltd. All rights reserved. Proprietary information and specifications subject to change without notice.
Message ID: 1351
Rate: As required. The maximum allowable rate is once every 100 ms (Note 1)
Message Length: Varies with message
Word No. Name Type Units Range
1-4 Message header
5 Header checksum
6 Sequence number (Note 2) I 0 to 32 767
7 to n-1 Any valid RTCM-104 raw data in multiples of 16 bits, not to exceed 32 16-bit words (Note 3)
n Data checksum (Note 1)
Note 1: ‘n’ must be less than or equal to 39. No more than 32 receiver 16-bit words of RTCM data should be delivered to the receiver
with anyone message. Word description, number of words, header 4, header checksum 1, reserved (sequence number) 1, RTCM
data <32, data checksum 1------ (max number of words <39).
Note 2: The sequence number is a count that indicates whether the data in a particular binary message has been updated or
changed since the last message input.
Note 3: Raw demodulated data must conform to the ‘6 of 8’ format described in the RTCM SC-1 04 standard. The data must also
be packed into one or more 16-bit words and should be ordered chronologically from earliest to latest. Specifically, Word 7 should
represent the earliest data and Word n-1 should represent the latest.
Within each word, the most significant bit (bit 15) should represent the latest received bit and the least significant bit (bit 0) should
represent the earliest received bit. (Note that according to RTCM ‘6 of 8’ format, bits 6 and 14 should be set marking (1) and bits 7
and 15 should be set spacing (0) for each word.) The intent of this bit ordering is to allow the user to pass on the raw RTCM data
without modification.
Table 3-41 Message 1351 (raw DGPS RTCM SC-104 data)
3.5.2.19 Message 1351 (raw DGPS RTCM SC-104
data)
This input message contains DGPS RTCM SC-l04
data. The message is provided for backwards
compatibility with the earlier MicroTracker GPS
receiver and may be used in lieu of the auxiliary
port data. The contents of the ‘raw DGPS RTCM
SC-l04 data’ message are described in Table 3-41.