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9-55
9 Troubleshooting and Maintenance
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
9-4 Even
t L
ogs
9
9-4-3 Error De
scr
iptio
ns
Event name
Bus Off Detected
Event code
8474 0000 hex
Meaning
A Bus Off error occurred (i.e., communications stopped because there were too many communications errors).
Source
PLC Function Module
Source details
CJ-series Unit
Detection
timing
When the I/O
connection is
established or
DeviceNet com-
munications are
performed
Error attributes
Level
Minor fault
Recovery
Cycle the power
supply or reset
the Controller.
Log category
System
Effects
User program
Continues.
Operation
The DeviceNet Unit is offline. Communications will not
operate. Error responses are returned to all communica-
tions requests. Data refreshing with the CPU Unit contin-
ues.
System-defined
variables
Variable
Data type
Name
None
---
---
Cause and
correction
Assumed cause
Correction
Prevention
The master and slave have different
baud rates.
Correct the settings so that the mas-
ter and slaves use the same baud
rate.
Set the master and slaves to the
same baud rate.
Communications cable lengths (trunk
line and branch lines) are unsuitable.
Refer to the communications specifi-
cations and adjust all of the communi-
cations cables to suitable lengths.
Refer to the communications specifi-
cations and adjust all of the communi-
cations cables to suitable lengths.
A communications cable is discon-
nected or loose.
Connect the communications cable
securely. If the communications cable
is broken, replace it.
Connect the communications cable
securely. Check the communications
cable to see if it is operating properly.
The terminating resistance is some-
where other than the ends of the trunk
line.
Connect terminating resistance only
to the ends of the trunk line.
Connect terminating resistance only
to the ends of the trunk line.
Noise
Implement noise countermeasures.
Implement noise countermeasures.
Attached
information
None
Precautions/
Remarks
None
Содержание CJ1W-DRM21
Страница 12: ...Manual Structure 10 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Страница 42: ...Revision History 40 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Страница 214: ...6 Message Communications 6 26 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Страница 345: ...Index 1 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 I Index ...
Страница 349: ......