GXB2000 Datasheet, PDF (32/60 Pages) Sony Corporation – 16-Channel GPS Receiver Module

GXB2000
1-2. Almanac Data Output
No.
BIT
76543210
Contents
1 10100100 Header
2 0xxxxxxx
•
•
•
•
•
•
•
•
•
•
44 0xxxxxxx
45 11011010 Terminator. "Z" + 80HEX
Example
Setting value
Output data
(HEX)
A4
—
DA
After the receiver receives an almanac output request, it transmits a response and then outputs the almanac
data. The above format is for 1 subframe of the almanac data, and 64 frames of this data are sent in succession.
Almanac communication data is sent by dividing the original data into 7-bit sections.
The almanac data stored in the GPS receiver memory has the configuration shown below. Normally each word
of the almanac data has 6-bit parity, but this is eliminated when the data is stored in the memory. In addition, a
16-bit checksum is added in consideration of communication.
WORD1
WORD2
WORD3
WORD4
WORD5
WORD6
WORD7
WORD8
WORD9
WORD10
Checksum
24 bits
24 bits
24 bits
24 bits
24 bits
24 bits
24 bits
24 bits
24 bits
24 bits
16 bits
The relationship between the above
data and the communication data is
shown to the right.
(1) Relationship between word data and communication data
23
0
Before conversion
31
After conversion 0
0
0
0
(2) Relationship between checksum and communication data
15
0
Before conversion
23
0
After conversion 0
0
0 00000
SS-3