Omron SYSMAC CS1W-SCB41-V1 Operation Manual page 370

Troubleshooting
Serial Indicator
communi- display
cations
mode
Serial com- The SD@/
munica- RD@ and
tions mode COM@ indi-
is set to cators are
protocol flashing, but
macro. the Unit or
Board can-
not perform
communi-
cations or a
communi-
cations
error some-
times
occurs.
The RDY
and ERC
indicators
are flash-
ing (ERR/
ALM).
The RDY
indicator is
lit and the
ERC indica-
tor is flash-
ing (ERR/
ALM).
Status Words allocated in
information, the CIO Area
etc.
A transmission Bit 15 (Transmission
error some- Error) of the words
times occurs. allocated in the CIO
Area n+8/n+18 is set
to ON.
There is an error in
bits 0 to 14.
--- Bit 00 (Protocol Data
Error) of the words
allocated in the CIO
Area n+1 is set to
ON.
--- Bits 00 to 03 (Port
Status Error Code)
of the words allo-
cated in the CIO
Area n+9/n+19 are
set to a value other
than 0 Hex. (An error
has occurred.)
Cause
The wiring is faulty.
The RS-422A/485 port
terminating resistance
setting is incorrect.
Adapters such as the NT-
AL001-E are incorrectly
wired, or the terminating
resistance setting is
incorrect.
A communications error
frequently occurs due to
noise and so on.
The protocol macro data
SUM value is abnormal.
An error has been
detected in the protocol
macros, making the oper-
ation impossible.
Section 11-3
Remedy
Check the wiring.
Turn ON the terminating
resistance of the Board
and the last node by
using the terminating
resistance switch. Turn
OFF the terminating
resistance of other
nodes.
Use shielded twisted pair
cables.
House the communica-
tions cables in a different
duct from those for power
lines and so on.
Review the operating
environment to prevent
noise problems.
Programming retry pro-
cessing for communica-
tions if necessary.
Use CX-Protocol to trans-
fer the correct protocol
data.
See note on page 343.
341