6 Message Formats
MiLLennium Command Descriptions Manual 41
RTCMA or RTCM1A
This log contains the same data available in the RTCM Standard Format Type 1 messages, but has been modified to
allow flexibility in using the RTCM data. The RTCM data has been reformatted to be available in ASCII
hexadecimal, utilizing a NovAtel header and terminates with a checksum.
This message was designed so that RTCM data can be intermixed with other NovAtel ASCII data over a common
communications port. The log is not in pure RTCM SC104 format. The header ($RTCM) and terminator (*xx) must
be stripped off at the receiving end, then the data will need to be converted from hexadecimal to binary before the
RTCM information is retrieved. The RTCM data is further defined by the RTCM rule (see the RTCMRULE command).
The RTCMA log can be directly decoded by other NovAtel GPSCard receivers operating as remote stations. They
will recognize the $RTCM header as a special data input command and the differential corrections data will be
directly applied. The GPSCard remote station receiving this log must have the ACCEPT command set to "ACCEPT
port COMMANDS".
Structure:
Example:
$RTCM,664142406B61455F565F7140607E5D526A5366C7C7F6F5A5B766D587D7F535C4B697F54594
060685652625842707F77555B766558767F715B7746656B*54[CR][LF]
RTCMB or RTCM1B
This log contains the same data available in the RTCM Standard Format Type 1 messages, but has been modified to
allow flexibility in using the RTCM data. The RTCM data has been reformatted to be available in NovAtel Binary
Format, utilizing a NovAtel binary header.
This message was designed so that RTCM data can be transmitted intermixed with other NovA tel binary data over
a common communications port. The log is not in pure RTCM SC104 format and is not directly usable as such.
GPSCard remote receivers cannot decode or interpret the RTCMB data (however, the GPSCard can directly interpret
RTCM and RTCMA). The 12 byte NovAtel binary header must be stripped off before the RTCM information can be
retrieved. The RTCM data is further defined by the RTCM rule (see the RTCMRULE command).
REMEMBER: Ensure that the RTCM rule is the same between all equipment.
Format: Message ID = 10 Message byte count = variable
RTCM1A
Example:
$RTCM,597E7D7F716F745A647D7E42405273505276777C7F736C514E7D477A7F7F
5A7E6E62675F406C567F6753725B675F7B436A646A7D787F675D4A505056687C6B
$RTCM rtcm data *xx [CR][LF]
Field # Field Type Data Description Example
1$RTCM NovAtel format ASCII header $RTCM
2 rtcm data hexadecimal representation of binary
format RTCM SC104 data 664142406B61455F565F7140607E5D526A5366C7
C7F6F5A5B766D587D7F535C4B697F54594060685
652625842707F77555B766558767F715B7746656B
3*xx Checksum *54
4[CR][LF] Sentence terminator [CR][LF]
Field # Data Bytes Format Offset
1 Sync 3 char 0
(header) Checksum 1 char 3
Message ID 4 integer 4
Message byte count 4 integer 8
2RTCM SC104 data variable 12