NavCom LAND-PAK Rev.N - Manual (Page 57)

Technical Reference Manual Rev. N
Blk = All; Blu = IOP w/Internal Radio ; Red = IOP & LBM ; Grn = Engine only
55
0x48 - SV Health Override Control - 6 + (2 x N) bytes
This message controls satellite health override as controlled by word 3, which in turn affects
channel assignments.
Record
Usage Command - Yes
Response - Yes Input: sets which satellites will be tracked and used for PVT;
Output: reports the current settings of the receiver health configuration
Ref Message Field Description
Data
Type
Units Range Scale
Byte
Count
STX 02 (hex) U08 1
PRA1 99 (hex) U08 1
PRA2 66 (hex) U08 1
ID 48 (hex) U08 1
Length 0x00xx U16 2
W1
Command Action
B1=0: Do not store in NVRAM
1: Store in NVRAM
B2=0: Do not use ACK/NAK
1: Use ACK/NAK
B3=0: Use Commanded Values
1: Use Default values
U08 1
W2 Reserved U08 1
Wn3
SV to override
0x01 - 0x20: SV PRN
B6=0: Use broadcast health
B6=1, B7=0: Force PRN healthy
B6=1, B7=1: Force PRN unhealthy
U16[]
PRN
1 to 32
n*2
CKSM Checksum U08 1
ETX 03 (hex) U08 1
1. For multiple command actions, the bits in W1 may be OR’ed.
2. W3 is repeated N times for multiple SVs.
3. All SVs revert to broadcast ephemeris health upon default (W1, B3=1).
4. Health override affects channel assignment.
5. On occasion, a particular satellite that is reported healthy may provide bad
positioning information. This satellite can be marked unhealthy by the user
and thereby omitted from the PVT solution, regardless of the satellite’s
elevation & azimuth. By the same token, a satellite that report’s it’s health to
be unhealthy, may be forced healthy by the user and used in the PVT solution
– at some measurement error risk. Obviously, this command is intended for
the sophisticated and well informed user.