Omron CJ1W-SCU32 Operation Manual page 302

9 Troubleshooting and Maintenance
Error conditions
Serial Indicator
communications status
mode
Serial communi- The RD@/SD@
cations mode is indicators flash,
set to Modbus- and an error
RTU Slave Mode. response was
returned to the
host.
The RD@/SD@
indicators flash,
but sometimes
there is no
response
returned.
Note The system settings can not be changed unless the power supply is cycled, the Unit is restarted,
or the port is restarted. Refer to 1-8 Basic Operating Procedure for details.
9-24
Confirmation of
device variable
Status
for CJ-series Unit,
information,
etc.
etc.
There is no *_P1(orP2)_TransErr
transmission Sta (Transmission
error. Error Status) is set to
0000 hex.
There is a *_P1(orP2)_TransErr
transmission (Transmission error) is
error. set to TRUE, or any of
*_P1(orP2)_OverRun
Err (Overrun Error),
*_P1(orP2)_FramingE
rr (Framing Error),
*_P1(orP2)_ParityErr
(Parity Error),
*_P1(orP2)_FCSErr
(FCS Check Error) is
set to TRUE.
There is a *_P1(orP2)_TransErr
transmission (Transmission error) is
error some- set to TRUE, or any of
times. *_P1(orP2)_OverRun
Err (Overrun Error),
*_P1(orP2)_FramingE
rr (Framing Error),
*_P1(orP2)_ParityErr
(Parity Error),
*_P1(orP2)_FCSErr
(FCS Check Error) is
set to TRUE.
There is a Terminating resis-
transmission tance switch (TERM
error some- ON/OFF) status
times.
There is a *_P1(orP2)_TransErr
transmission Sta (Transmission
error some- Error Statsu) is not set
times.
to 0000 hex.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Cause
A command was sent Review the host's settings
from the host with and program (such as param-
incorrect parameters. eter settings) based on the
response contents.
The communications Review the System Settings,
conditions and baud the host's settings and pro-
rate do not match the gram (such as commands
settings at the host. and frame format) based on
the response contents, and
the transmission error codes
in *_P1(orP2)_TransErrSta
(Transmission Error Status).
The baud rate is out- Review the System Settings.
side the allowable
Review the host's settings
range, and the stop
and program (such as baud
bits do not match,
rate and frame format).
which causes the bits
to be out of alignment.
Cables are incorrectly Check the wiring.
connected.
The RS-422A/485
Turn ON the terminating
port terminating resis-
resistance at two last loca-
tance setting is incor-
tions (host side or Unit side).
rect.
Turn OFF the terminating
Adapters such as the resistance of other Units.
NT-AL001 are incor-
rectly wired or the ter-
minating resistance is
incorrectly set.
Transmission errors Use shielded twisted-pair
occur that are caused cables.
by noise interference.
Lay power lines separately by
using ducts.
Review the installation envi-
ronment to reduce noise inter-
ference.
Programming retry process-
ing for communications if nec-
essary.
Remedy