WAAS G-III Reference Receiver User Manual Rev 1
85
Chapter 5
Data Logs
The following rules apply to logs:
• The majority of logs are output in binary format only.
The
RXCOMMANDSB
log is the only log that reports the configuration settings in ASCII format.
• Logs are generated by the receiver in response to the LOG command. For information about the
LOG command, see
Section 4.4.14 LOG
on
Page 60
.
• All logs are protected with a 32-bit CRC at the end of each message. Refer to
32-Bit CRC
on page
90 for CRC polynomial and computation.
• Some logs have repeating data sets. This is represented by a double line between fields.
• All receiver logs are in little-endian format.
• Reserved fields in logs are reserved for manufacturer’s use and may be non-zero.
5.1
Log Header
There are two types of logs in the G-III Reference Receiver: legacy logs and G-III logs. The legacy logs ensure
backwards compatibility with the G-II Reference Receiver, while the G-III logs are updated to include new
information and are expanded to allow for the new GPS signals.
The legacy logs have a header very similar to the G-II Reference Receiver logs, with some of the fields set to
reserved. In the legacy log header, the reserved fields are set to zero.
The G-III log header can be uniquely identified by the four byte synchronization pattern "0xAACC4756".
Table 27: Legacy Log Header Format
Field
Field Name
Description
Format
# Bytes
Binary
Offset
1
Sync
Hexadecimal 0xAA
Char
1
0
2
Sync
Hexadecimal 0x44
Char
1
1
3
Sync
Hexadecimal 0x12
Char
1
2
4
Header
length
Length of the header
Uchar
1
3
5
Message id
Message ID
Ushort
2
4
6
Reserved 1
Reserved. Set to 0.
Char
1
6
7
Reserved 2
Reserved. Set to 0.
Char
1
7
8
Message
length
Length of the message in bytes. This does not
include the header nor the CRC
Ushort
2
8
9
Reserved 3
Reserved. Set to 0.
Ushort
2
10
10
Reserved 4
Reserved. Set to 0.
Char
1
12