Omron CJ1W-SCU32 Operation Manual page 292

9 Troubleshooting and Maintenance
Transmission Failure (SerialSend Instruction)
Error conditions
Serial Indicator
communications display
mode
Serial communica- ---
tions mode is No-
protocol Mode.
Protocol Macro ---
Mode, Serial
Gateway
Mode, Mod-
bus-RTU Slave
Mode or Loop-
back Test
Mode
The serial commu- The SD@ indi-
nications mode is cators do not
set to No-protocol flash at all.
Mode. (Communica-
tions were not
electrically
established.)
The SD@ indi-
cators flash but
communica-
tions are not
always possi-
ble.
9-14
Confirmation of device variable
for CJ-series Unit, etc.
Status
and other
conditions
--- Bits 12 to 15 (Serial communica-
tions mode) of
*P1(orP2)_SysSetSta are set to a
value other than 3 hex.
--- During execu-
tion of the Seri-
alSend
instruction
--- ---
--- ---
--- *_P1(orP2)_HlkCTSCtlCfg (CTS
Control) is ON, but
*_P1(orP2)_SigCSSta (CS signal)
is FALSE.
A transmission *_P1(orP2)_TransErr (Transmis-
error occurred. sion error) or
*_P1(orP2)_OverRunErr (Overrun
Error) is TRUE.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Cause
The serial commu-
nications mode is
not set correctly.
Command end The serial commu-
code such as nications mode is
0401 hex (unde- not set correctly.
fined command)
is returned.
A hardware error
occurred.
The cables are not
connected cor-
rectly.
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 is
incorrect.
CTS control is set,
but the Remote
Unit's RTS (RS)
signal 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 outside the
permissible range,
or the bits such as
stop bits are mis-
aligned.
Remedy
---
Set bits 08 to 11
(Serial communica-
tions mode) of
*_P1(orP2)_PortCfg
to 3 hex (No-protocol
Mode).
Set the serial commu-
nications mode to
Loopback Test Mode
and check the trans-
mission 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 control.
Input the RTS (RS)
signal from the
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)