Omron CJ1W-SCU32 Operation Manual page 289

Error conditions
Serial Indicator
communications display
mode
The serial commu- ---
nications mode is
set to No-protocol
Mode.
The RD@ indi-
cators flash
but communi-
cations are not
always possi-
ble.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Confirmation of device
variable for CJ-series Unit, etc.
Status and
other
conditions
--- ---
--- ---
--- *_P1(orP2)_HlkCTSCtlCfg (CTS
Control) is TRUE, but
*_P1(orP2)_SigCSSta (CS signal)
is FALSE.
A transmis- *_P1(orP2)_TransErr (Transmis-
sion error sion Error) or
occurred. *_P1(orP2)_OverRunErr (Overrun
Error) is TRUE.
9 Troubleshooting and Maintenance
Cause
A hardware error
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 adapt-
ers such as the NT-
AL001 is incorrect.
CTS control is set,
but the Remote
Unit's RTS (RS) sig-
nal is not input in the
Local Unit's CTS
(CS) signal.
The settings in the
System Settings
such as baud rate
and frame format do
not match those of
the remote device.
The baud rate is out-
side the permissible
range, or the bits
such as stop bits are
misaligned.
Remedy
Conduct a loopback
test in serial commu-
nications mode to
check the transmis-
sion lines. If an error
occurs during the
test, replace the Unit.
Check the wiring.
Check the setting of
the 2/4-wire switch.
Wire all nodes by
using the 4-wire
method.
Perform either of the
following:
• Loop the RTS (RS)
-CTS (CS) signals
of the Local Unit.
• Disable CTS con-
trol.
• Input the RTS (RS)
signal from
Remote Unit to the
CTS (CS) signal of
the Local Unit and
use CTS control.
Correct the System
Settings.
Revise the remote
device settings and
program (e.g., baud
rate, frame format)
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