PoE
AP
Router
183
4.2
Data
Logging
Data
logging
is
the
process
of
collecting
and
storing
data
over
a
period
of
time
in
order
to
analyze
specific
trends
or
record
the
data
‐
based
events/actions
of
a
system,
or
connected
devices.
Data
logging
function
is
a
very
useful
and
also
important
feature
for
SCADA
telemetry;
it
makes
the
monitoring
and
analyzing
tasks
easier
by
checking
the
status
and
historical
data
during
whole
data
acquisition
period.
Even
facing
the
network
connection
problems
with
remote
NOC/SCADA
side,
you
can
also
enable
the
data
logging
proxy
function
provided
by
the
purchased
gateway
and
keep
doing
the
data
acquisition
and
storing
the
collected
data
in
local
storage
(in
.CSV
file
format).
When
the
network
connection
recovered,
admin/user
can
download
the
data
log
files
manually
via
FTP
or
web
UI
for
further
reference
and
maintenance.
The
Modbus
Cellular
Gateway
provides
a
complete
data
logging
function
for
collecting
the
Modbus
transaction
data
for
application
requirements.
There
are
some
data
logging
schemes
to
meet
different
management
requirements.
They
are
the
Sniffer
Mode,
Offline
Proxy
Mode,
Full
‐
Time
Proxy
Mode,
and
the
mixed
modes
for
sniffer
and
proxy
combinations.
With
the
Sniffer
mode
enabled,
the
gateway
will
monitor
and
record
the
communication
among
a
specific
Modbus
Master
and
related
slaves.
It
will
store
the
Modbus
communication
as
log
files
and
administrator
can
check
what
Modbus
communication
went
over
the
Modbus
gateway,
and
if
there
is
any
communication
loss
