Omron SYSMAC CJ1W-SCU21-V1 User Manual

332
Troubleshooting Section 11-3
The serial com-
munications
mode is set to no-
protocol mode.
The SD@/
RD@ and
COM@ indi-
cators do not
flash at all.
(Communica-
tions have not
been electri-
cally estab-
lished.)
--- --- A hardware error
has occurred.
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.
--- --- 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.
Check the wiring.
Reset the port to
the correct wiring
setting.
Wire all nodes
using the 4-wire
method.
--- CTS control is ON, but bit 04
of word n+7/n+17 (CS) is
OFF.
CTS control is
set, but the
remote node’s
RS signal is not
being input in the
local node’s CS
signal.
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.
The SD@ and
COM@ indi-
cators flash
but communi-
cations are
not always
possible.
A transmis-
sion error has
occurred.
CIO word n+8/n+18 bit 15
(transmission error) or bit 04
(overrun error) is ON.
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.
Correct the set-
tings in the Setup
Area.
Revise the remote
device settings and
program (e.g., baud
rate, frame format)
Error conditions Words allocated in CIO
Area
Cause Remedy
Serial communi-
cations mode
Indicator
display
Status and
other condi-
tions

Omron SYSMAC CJ1W-SCU21-V1 Specifications

General

Brand	Omron
Model	SYSMAC CJ1W-SCU21-V1
Category	Network Hardware
Language	English