3.
Troubleshooting
In
this
chapter,
we
will
explain
how
to
troubleshoot
the
communication
problems.
Possible
causes
of
TIMEOUT
Situation
#1
:
The
slave
device
is
not
turned
on
or
the
transfer
function
of
the
slave
site
may
fail.
Solution:
Check
the
slave
device
is
powered
up
and
the
communication
function
is
enabled.
Situation
#2
:
The
COM
port
number
to
which
the
slave
device
is
connected
is
not
the
same
with
the
UseComPort
setting
in
the
polling
definition.
Solution:
Connect
the
slave
device
to
the
COM
port
number
that
is
defined
in
the
polling
definition,
or
fix
the
UseComPort
parameter
to
the
virtual
COM
port
number
that
the
slave
device
is
connected
to.
Copyright
©
2014
ICP
DAS
Co.,
Ltd.
All
Rights
Reserved.
∗
E
‐
mail:
‐
26
‐
Situation
#3
:
The
wiring
for
communication
is
wrong.
Solution:
Exchange
the
D+
and
D
‐
wiring
of
RS
‐
485
connection,
or
exchange
the
Rx
and
Tx
wiring
of
RS
‐
232
connection,
and
check
the
GND
wiring
is
correct
between
the
slave
device
and
the
MDC
‐
700
module.
Situation
#4
:
The
Baud
Rate
or/and
Data
Format
settings
in
the
polling
definition
are
incorrect.
Solution:
Check
and
fix
the
difference
of
the
Baud
Rate
and
Data
Format
settings
between
the
polling
definition
and
the
slave
device.
ComPortNo
BaudRate
DataBit
Parity
StopBit Timeout PollDelay
Operating
Mode
1
9600
8
0
1
120
100
Master
2
9600
8
0
1
3000
1000
Master
3
9600
8
0
1
3000
1000
Master
4
9600
8
0
1
120
100
Master
5
9600
8
0
1
120
100
Master
