User`s guide

Chapter 5 - I/O Commands
REQUEST UTC/IONOSPHERIC DATA (@@Bp)
Motorola Binary Format
Request Current UTC/Ionospheric Data:
@@BpmC<CR><LF>
where:
m = mode 0 = output response once (polled)
1 = output response when either UTC or
ionospheric data changes
C = checksum
Message length: 8 bytes
Response to above command:
@@CoabcdefghAAAAaaaadtwWnDC<CR><LF>
where:
a, b, c, d, e, f, g, and h = Ionospheric Data (see ICD-GPS-200, Table 20-X for scale
factors)
a = α0 -128…+127 seconds
b = α1 -128…+127 seconds/semi-circle
c = α2 -128…+127 seconds/(semi-circle)
2
d = α3 -128…+127 seconds/(semi-circle)
3
e = β0 -128…+127 seconds
f = β1 -128…+127 seconds/(semi-circle)
g = β2 -128…+127 seconds/(semi-circle)
2
h = β3 -128…+127 seconds/(semi-circle)
3
AAAA, aaaa, d, t, w, and W = UTC Data (see ICD-GPS-200, Table 20-IX for scale
factors)
AAAA = A0 -2,147,483,648…+2,147,483,647 seconds
aaaa = A1 -8,388,608…+8,388,607 seconds/second
d = ∆t
LS
-128…+127 seconds
t = t
ot
0…602,112 seconds
w = WN
t
0…255 weeks
W = WN
LSF
0…255 weeks
n = DN 1…7 days
D = ∆t
LSF
-128…+127 seconds
C = checksum
Message length: 29 bytes
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
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