Modbus
Cellular
Gateway
Index
skipping
is
used
to
reserve
slots
for
new
function
insertion,
when
required.
326
computer,
allowing
the
host
computer
to
establish
a
connection
with
and
get
data
from
the
serial
device,
the
operation
mode
for
the
"Virtual
COM"
function
is
required
to
be
"TCP
Server".
In
this
mode,
IOG
gateway
provides
a
unique
"IP:
Port"
address
on
a
TCP/IP
network.
It
supports
up
to
4
simultaneous
connections,
so
that
multiple
hosts
can
collect
data
from
the
same
serial
device
at
the
same
time.
Scenario
Description
When
the
Internet
Host
Computer
wants
to
get
the
serial
data
via
the
IOG
Gateway,
it
will
try
to
establish
a
TCP
connection
to
the
gateway
if
the
connection
is
off.
After
the
data
has
been
transferred,
the
gateway
automatically
disconnects
from
the
host
computer
by
using
the
TCP
alive
check
timeout
or
idle
timeout
settings.
Parameter
Setup
Example
Following
tables
list
the
parameter
configuration
as
an
example
for
the
"TCP
Server"
mode
in
"Virtual
COM"
function,
as
shown
in
above
diagram.
Use
default
value
for
those
parameters
that
are
not
mentioned
in
the
tables.
Configuration
Path
[Virtual
COM]
‐
[Configuration]
Operation
Mode
TCP
Server
Listen
Port
4001
WAN
Interface
All
WANs
Trust
Type
Specific
IP
Max
Connection
4
Connection
Idle
Timeout
1
(0
‐
60)
min
Alive
Check
Timeout
1
(0
‐
60)
min
Configuration
Path
[Virtual
COM]
‐
[Trusted
IP
Definition]
ID
1
Host
140.116.82.98
Definition
■
Enable
Scenario
Operation
Procedure
In
above
diagram,
the
"IOG
Gateway"
is
the
gateway
that
attaches
a
serial
device
and
the
gateway
has
a
3G/LTE
WAN
interface
to
connect
to
the
Internet.
A
remote
Internet
host
computer
whose
IP
address
is
140.116.82.98
has
a
management
system
in
it
to
collect
and
process
the
serial
data
via
the
gateway.
Please
be
noted
that
the
operation
mode
of
the
virtual
COM
function
in
the
gateway
is
"TCP
Server".
When
the
Internet
Host
Computer
wants
to
collect
data
from
the
serial
device
via
the
gateway,
it
will
establish
a
TCP
connection
to
the
"IOG
Gateway"
if
the
connection
is
off.
After
the
data
has
been
transferred,
the
gateway
automatically
disconnects
from
the
host
computer
upon
alive
check
timeout
or
connection
idle
timeout.
Finally,
the
host
computer
can
process
the
collected
serial
data
and
make
further
decisions.
UDP
Mode
