Omron SYSMAC CS1W-SCB41-V1 Operation Manual page 361

Troubleshooting
Error conditions
Serial communi- Indicator
cations mode display
The serial com- The SD@/
munications RD@ and
mode is set to no- COM@ indi-
protocol mode. cators do not
flash at all.
(Communica-
tions have not
been electri-
cally estab-
lished.)
The SD@ and
COM@ indi-
cators flash
but communi-
cations are
not always
possible.
332
Words allocated in CIO
Status and
other condi-
tions
--- ---
--- ---
--- CTS control is ON, but bit 04
of word n+7/n+17 (CS) is
OFF.
A transmis- CIO word n+8/n+18 bit 15
sion error has (transmission error) or bit 04
occurred. (overrun error) is ON.
Cause
Area
A hardware error
has occurred.
The cables are
not connected
correctly.
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 incorrect.
CTS control is
set, but the
remote node's
RS signal is not
being input in the
local node's CS
signal.
The settings in
the Setup Area
such as baud
rate and frame
format do not
match those of
the remote
device. The baud
rate is outside
the permissible
range, or the bits
have been dis-
placed due to a
stop bit error or
other error.
Section 11-3
Remedy
Conduct a loopback
test in serial com-
munications mode
to check the trans-
mission lines. If an
error occurs during
the test, replace the
Board or Unit.
Check the wiring.
Reset the port to
the correct wiring
setting.
Wire all nodes
using the 4-wire
method.
Perform either of
the following:
Loop the RS-CS
signals of the local
node.
Disable CTS con-
trol.
Input the RS signal
from the remote
node to the CS sig-
nal of the local
node and use CTS
control.
Correct the set-
tings in the Setup
Area.
Revise the remote
device settings and
program (e.g., baud
rate, frame format)