XW-4
（
CAS-10
）
Amateur Radio Satellite User's Manual
9
/
31
V2.0 by BA1DU
龚万骢
3
、
GMSK telemetry data
：
（
1
）
GMSK telemetry frame format and communication protocol
XW-4(CAS-10) satellite GMSK telemetry data is sent in the AX.25 UI frame format. The user data of each frame is 126 bytes,
and the allocation is as follows:
Function code
Telemetry data content
7Byte
119Byte
W0~W6
：
0x0100010001007E
W7~W125
（
2
）
GMSK telemetry data format and analysis method
Sending
order
Starting
position
Data
length
Telemetry data function description
Telemetry data parsing algorithm
1
W7
6Byte
Satellite time
W1-Year: 00
～
99, representing 2000
～
2099
W2-Month: 01
～
12, representing January to December
W3-Day: 01
～
31, representing 1st
～
31st
W4-Hour: 00
～
23, representing 0:00
～
23:00
W5-minute: 00
～
59, representing 0 minutes
～
59 minutes
W6-second: 00
～
59, representing 0 seconds
～
59 seconds
2
W13
6Byte
48 hours reset time
W1-Year: 00
～
99, representing 2000
～
2099
