Omron CJ1W-SCU32 Operation Manual page 329

Event name Overrun Error, Framing Error, or Parity Error (Transmis-
sion Error)
Meaning An overrun error, framing error, or parity error occurred.
Source PLC Function Module
Error attributes Level
Effects User program
System-defined Variable
variables
None
Cause and Assumed cause
correction
The communications conditions and
baud rate settings do not match the
host.
Noise or other external interference.
The baud rate is outside the allowable
range or there are bit errors due to dif-
ferent stop bit settings or other
parameters.
• The communications cable wiring is
faulty.
• Terminating resistance is not set
correctly for the RS-422A/485 ports.
• Wiring is faulty or terminating resis-
tance is not set correctly on an NT-
AL001 or other Adapter.
Attached Attached information 1: Port number where error was detected
information
Precautions/ You can check the number of transmission errors (i.e., overrun errors, framing errors, and parity errors) in the
Remarks *_P1_MbsTxErrCnt and *_P2_MbsTxErrCnt device variables.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Source details
Observation Recovery
Continues. Operation
Data type
---
Correction
Review the system settings, host set-
tings, and programming, including the
command format and response for-
mat, based on *_P1_TransErrSta and
*_P2_TransErrSta (Transmission
Error Status).
• Use shielded twisted-pair cables for
the communications cables.
• Wire the communications cables in
separate ducts from power lines.
• Check the environment for noise.
• If required, perform retry processing
for communications.
• Review the system settings.
• Review the baud rate and other
host settings, and the programming,
including the command format and
response format.
• Check the communications cable
connections.
• Turn ON the terminating resistance
(with the terminating resistance
ON/OFF switch) at both ends (at
the host).
9 Troubleshooting and Maintenance
Event code 846C 0000 hex
CJ-series Unit Detection
timing
--- Log category
Not affected.
Name
---
Prevention
Perform countermeasures in
advance.
During Modbus-
RTU Slave Mode
System
9
9-51