Omron SYSMAC CJ1W-SCU21-V1, Operation Manual

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Troubleshooting Section 11-3
Serial com-
munica-
tions mode
is set to
protocol
macro. The SD @ /
RD @ and
COM @
indicators
are flash-
ing, but the
Unit or
Board can-
not perform
communi-
cations.
Send data has
already been
transmitted, but
there is no
response from
the remote
node. The contents of the
words allocated in
the CIO Area n+5/
n+15 (System Port
Settings) do not
match those of the
remote node. The baud rate is outside
the allowable range, or
there are bit errors due to
mismatched stop bits and
so on. Review the Setup Area
settings.
Review the remote node
settings and the program
(including the baud rate,
frame format, and so on).
Bit 15 (Transmission
Error) of the words
allocated in the CIO
Area n+8/n+18 is set
to ON.
There is an error in
bits 0 to 14.
The wiring is faulty.
The setting of the 2/4-
wire switch for the RS-
422A/485 port does not
match the actual wiring.
The wiring of adapters
such as the NT-AL001-E
is faulty.
Check the wiring.
Turn ON the terminating
resistances of the Board
and the last node. Turn
OFF the terminating
resistances of other
nodes.
The SD @ /
RD @ and
COM @ indi-
cators are
flashing, but
the Unit or
Board can-
not perform
communi-
cations or a
communi-
cations
error some-
times
occurs.
A transmission
error occurs. Bit 15 (Transmission
Error) of the words
allocated in the CIO
Area n+8/n+18 is set
to ON.
There is an error in
bits 0 to 14.
The Setup Area settings
such as the baud rate
and frame format differ
from those of the remote
node. The baud rate is
outside the allowable
range, or there are bit
errors due to mismatched
stop bits and so on. Review the Setup Area
settings.
Review the remote node
settings and the program
(including the baud rate,
frame format, and so on).
The contents of the
words allocated in
the CIO Area n+5/
n+15 (System Port
Settings) do not
match those of the
remote node.
Data is received
through CX-Pro-
tocol transmis-
sion line trace,
but the protocol
macros behave
as if no data is
received. --- Because response from
the remote node in half-
duplex mode is received
too fast, the data received
from the time the data
send processing was
completed until the Send
operation was completed
is discarded. Use full-duplex mode.
The remote
node sometimes
returns no
response to sent
data. Response
may be received
by performing
retries. --- The transmission timing
is too fast for the remote
node to receive data. Set or increase the trans-
mission wait time (time to
await data transmission)
in step units.
Serial
communi-
cations
mode
Indicator
display
Status
information,
etc.
Words allocated in
the CIO Area
Cause Remedy