14 Diagnostics
14.2 Detail Error Check
218
FX
3U
-CAN User's Manual
*1.
Any CANopen
®
node will check all CAN messages on the bus for errors. Depending on the error state,
the action that the node will take is different:
-
In error active:
The node will actively mark the frame as invalid.
-
In error passive:
The node will not actively mark the frame as invalid to avoid bus disturbance if the node itself has an H/W problem.
Bit 3
CAN bus off error
The FX
3U
-CAN is bus OFF.
The FX
3U
-CAN has too many transmission errors. Check the following points in the network. And then,
turn on the power for PLC again or restart the FX
3U
-CAN.
→
For module restart, refer to Section 6.8
•
Check that the terminating resistors at both ends of the network are connected.
•
Check that all nodes have the same baud rate setting.
•
Check that all nodes have a unique Node-Id setting.
•
Check that the CAN_H, CAN_L and CAN_GND wires are not broken.
•
Check that the CAN_SHLD is grounded.
•
Check that the CAN_SHLD is connected at all nodes.
•
Check that the CAN cable wires do not short circuit other CAN cable wires.
Bit 4
FLASH memory
error
FLASH memory error has occurred.
Invalid data in the Flash memory might be caused by power loss during a write operation to the Flash
ROM. If this error flag is not cleared after a module reset (BFM #25 bit 0) or another power cycle, please
contact your local Mitsubishi Electric representative.
→
For module restart, refer to Section 6.8
Bit 5
•
CANopen
®
modes: Write access while module is in initialisation mode.
Write to BFMs, after BFM #25 bit 7 is OFF.
→
For the communication status (BFM #25), refer to Section 6.8
•
Layer 2 mode:
Invalid write access to configuration BFM while in online/initialisation mode.
Do not write to configuration BFM when module is online. Write to configuration BFMs, after switching
to configuration mode and off line mode.
→
For the communication status (BFM #25), refer to Section 6.8
This failure is displayed in BFM #40.
Bit 6
BFM setting error
BFM setting error has occurred.
ON when a value that is out of range is written to a BFM. This failure BFM address is displayed in BFM
#39. In Layer 2 mode, this bit can not be reset while the module is in online mode.
→
For BFM #39, refer to Section 6.17
Bit 7
FROM/TO
watchdog timer
error
FROM/TO watchdog timer expired. Please see the above note.
This error flag can be reset by writing to BFM #26.
→
For the FROM/TO watchdog, refer to Section 6.9
Bit 8
Internal data
queue overflow
Internal data queue overflowed.
Extreme bus load can cause the internal queues to overflow. Decrease the bus load.
At a low baud rate, data exchange that is too fast can overflow the CAN Transmit Buffer (Depends also on
the bus-load of the CAN).
→
For Data Exchange Control flag, refer to Section 6.4
Bit 9
Reserved
Bit 10
CANopen
®
NMT Error Control
failure
CANopen
®
NMT Error Control failure has occurred.
At least one of the assigned NMT slaves failed during NMT Error Control.
→
For NMT Error Control failure, refer to Section 6.24
Bit 11
Baud rate change
error
Baud rate change error has occurred.
ON when an invalid baud rate is written to BFM #24. In this case, the BFM will keep its former value.
→
For the baud rate setting, refer to Section 6.7
Bit 12
Node address
change error
Node address change error has occurred.
ON when an invalid node address is written to BFM #27. In this case, the BFM will keep its former value.
→
For the node address setting, refer to Section 6.10
Bit 13
CANopen
®
emergency
CANopen
®
emergency message was received from the assigned slave.
→
For the emergency message, refer to Section 6.23
Bit 14
CAN error passive
state
This flag shows the CAN error active state/passive state
*1
.
OFF: Error active state
CAN reception error counter value is in the range of K0 to K127.
ON:
Error passive state
CAN reception error counter value is K128.
This bit will be reset automatically if the internal error counters return back to below K128.
→
For the CAN transmission error counter, refer to Section 6.13
→
For the CAN reception error counter, refer to Section 6.14
Bit 15
Layer 2 Message
specific error
Layer 2 Message specific error exists.
Check the Layer 2 Message specific error code in BFM #401 to #442.
→
For the Layer 2 Message specific error code, refer to Section 9.2
Bit No.
Description
Summary of Contents for FX3U-CAN
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