your position is our focus
4.4.3.4
UBX Message Flow
There
are
certain
features
associated
with
the
messages
being
sent
back
and
forth:
•
Acknowledgement
ssages
from
the
Cla
t
to
the
receiver,
the
receiver
will
send
an
Acknowledge
or
a
Not
age
back
t the
sender,
depending
on
whether
or
not
the
message
was
processed
•
Polling
Mechanism
ou
There
is
not
a
single
specific
me
s
designed,
that
w e
essage
with
n
mess
To
c
utput
message
4 4.
otocol
The
l
is
an
indus
e
electronics
and
was
o
to
allow
data
ships.
Nowadays,
it
is
a
de-facto
standar
d
please
refer
to
“NMEA
0183
Stan
onic
Devices",
Version
2.300,
March
1,
1998.
T
ecification
of
the
p
at
http://www.nmea.org.
Note
UBX
protocol
offers
ol.
It’s
optimized
to
commun
est
performance
and
optimal
ugging.
4.4.4.1
NMEA Protocol Overv
The
ASCII-b
d.
GPS
start
w
at
follows.
NMEA
messages
have
a
c
ows
the
structure
of
a
NMEA
protocol
When
me
ss
CFG
are
sen
Acknowledge
mess
corr
o
ectly.
Most
messages
that
can
be
tput
by
the
receiver
can
also
be
polled.
ssage,
which
polls
any
other
message.
The
UBX
protocol
wa
h n
sending
a
m
age
is
polled.
o
payload
(or
just
a
single
parameter
which
identifies
the
poll
request)
the
onfigure
UBX
o
s
to
a
specific
repetition
rate
use
UBX-CFG-MSG.
. 4 NMEA
Pr
NMEA
protoco
try-standard
protocol
that
was
developed
for
marin
riginally
designed
exchange
between
various
sensors
and
navigation
equipment
aboard
d
for
GPS
receiver
data
output.
For
further
information
on
the
NMEA
Standar
dard
For
Interfacing
Marine
Electr
he
full
sp
rotocol
is
available
from
the
National
Marine
Electronics
Association
a
greater
flexibility
and
more
powerful
messages
than
NMEA
protoc
icate
with
u-center
AE
software
to
get
the
b
deb
iew
NMEA
protocol
is
an
specific
messages
all
ased
protocol.
Records
start
with
a
$
and
end
with
carriage
return/line
fee
ith
$GPxxx
where
xxx
is
a
three-letter
identifier
of
the
message
data
th
hecksum,
which
allows
detection
of
corrupted
data
transfers.
Figure 72
sh
message.
GPS
Modules
-
System
Integration
Manual
(SIM)
(incl.
Reference
Design)
Receiver
Description
GPS.G4-MS4-05007-A1
Page 85
