Omron CQM1H-SCB41 Operation Manual page 140

Troubleshooting
Serial commu- Indicator
nications status
mode
Serial commu- The COMM@
nications mode indicators are
is set to Host flashing, but the
Link. (Contin- response has
ued) not been
returned to the
host.
The COMM@
indicators are
flashing, and an
error response
has returned to
the host.
The COMM@
indicators are
flashing, but
sometimes
there is no
response
returned.
Status I/O memory
information,
etc.
There is a The error code in
transmission IR 20100 to
error. IR 20103 for port 1
or IR 20108 to
IR 20111 for port 2
is 1 (parity error), 2
(framing error), or 3
(overrun error).
There is no IR 20100 to
transmission IR 20103 or
error. IR 20108 to
IR 20111 are 0 Hex.
There is a The error code in
transmission IR 20100 to
error. IR 20103 for port 1
or IR 20108 to
IR 20111 for port 2
is 1 (parity error), 2
(framing error), or 3
(overrun error).
There is an The error code in
intermittent IR 20100 to
transmission IR 20103 for port 1
error. or IR 20108 to
IR 20111 for port 2
is 1 (parity error), 2
(framing error), or 3
(overrun error).
Terminating resis-
tance switch
(TERM) status
The error code in
IR 20100 to
IR 20103 for port 1
or IR 20108 to
IR 20111 for port 2
is not 0.
Cause
The communica- Review the PC Setup, the
tions conditions and host's settings, and pro-
baud rate do not gram (such as commands
match the settings and frame format) based
at the host. on the response and the
error code.
There is noise inter- Use shielded twisted-pair
ference. cables.
Lay power lines sepa-
rately using ducts.
Review the installation
environment to reduce
noise interference.
A command was Review the host's settings
sent from the host and program (such as
with incorrect parameter settings) based
parameters. on the response contents.
The communica- Review the PC Setup, the
tions conditions and host's settings and pro-
baud rate do not gram (such as commands
match the settings and frame format) based
at the host. on the response, and the
error code in IR 20100 to
IR 20103 or IR 20108 to
IR 20111.
The baud rate is Review the PC Setup.
outside the allow-
Review the host's settings
able range, and the
and program (such as
stop bits do not
baud rate and frame for-
match, causing the
mat).
bits to be out of
alignment.
Cables are incor- Check the wiring.
rectly connected.
The RS-422A/485
Turn ON the terminating
port 2-wire/4-wire
resistance of the Serial
terminating resis-
Communications Board
tance setting is
and the last node by using
incorrect.
the terminating resistance
Adapters such as switch. Turn OFF the ter-
the NT-AL001-E are minating resistance of
incorrectly wired or other nodes.
the terminating
resistance is incor-
rectly set.
Transmission errors Use shielded twisted-pair
are occurring that cables.
are caused by noise
Lay power lines sepa-
interference.
rately using ducts.
Review the installation
environment to reduce
noise interference.
Section 9-2
Remedy
125