Omron CQM1H-SCB41 Operation Manual page 144

Troubleshooting
Serial Indicator
communi- display
cations
mode
Serial com- The
munica- COMM@
tions mode indicators
is set to do not flash
protocol at all.
macro. (Communi-
(Continued) cations
have not
been elec-
trically
estab-
lished.)
The
COMM@
indicators
are flash-
ing, but the
Serial Com-
munica-
tions Board
cannot per-
form com-
munications
or a com-
munica-
tions error
sometimes
occurs.
Status I/O memory
information,
etc.
Send data has The contents of the
already been words allocated in
transmitted, but settings in the PC
there is no Setup do not match
response from those of the remote
the remote node.
node.
The error code in
IR 20100 to
IR 20103 for port 1
or IR 20108 to
IR 20111 for port 2 is
not 0.
---
A transmission The error code in
error occurs. IR 20100 to
IR 20103 for port 1
or IR 20108 to
IR 20111 for port 2 is
not 0.
The settings in the
PC Setup do not
match those of the
remote node.
Data is received ---
through CX-Pro-
tocol transmis-
sion line trace,
but the protocol
macros behave
as if no data is
received.
The remote ---
node sometimes
returns no
response to sent
data. Response
may be received
by performing
retries.
Cause
The baud rate is outside
the allowable range, or
there are bit errors due to
mismatched stop bits and
so on.
The wiring is faulty.
The setting of the 2/4-
wire switch for the RS-
422A/485 port does not
match the actual wiring
(WIRE).
Wiring of adapters (e.g.,
NT-AL001-E) is faulty.
Hardware failure.
The PC Setup settings
such as the baud rate
and frame format differ
from those of the remote
node. The baud rate is
outside the allowable
range, or there are bit
errors due to mismatched
stop bits and so on.
Because response from
the remote node is
received too fast, the data
received from the time
the data send processing
was completed until the
Send operation was com-
pleted is discarded.
The transmission timing
is too fast for the remote
node to receive data.
Section 9-2
Remedy
Review the PC Setup set-
tings.
Review the remote node
settings and the program
(including the baud rate,
frame format, and so on).
Check the wiring.
Turn ON the terminating
resistances of the Serial
Communications Board
and the last node. Turn
OFF the terminating
resistances of other
nodes.
Replace the Serial Com-
munications Board.
Review the PC Setup set-
tings.
Review the remote node
settings and the program
(including the baud rate,
frame format, and so on).
Check the settings of the
remote node and review
programming (i.e., the
timing of sending
response data).
Set or increase the trans-
mission wait time (time to
await data transmission)
in step units.
129