12 Diagnostics
12.2 Detail Error Check
96
FX
3U
-J1939 User's Manual
*1.
The configuration must not be changed while the FX
3U
-J1939 is set to online or initialization state.
Before changing the configuration, set BFM #25 bit 4 to OFF (configuration mode) and wait until BFM
#25 bit 7 and 0 are OFF (module offline). Also make sure the Configuration is not being stored/
restored to the internal FLASH memory. Check that BFM #22 bit 0 to 2 are OFF before changing the
configuration.
The configuration BFMs are #21, #24, #25 (bit 2), #27, #40 to #48, #500 to #973, #1100 to #1267,
#1900 to #1927 and #3000 to #3799.
In Layer 2 communication mode, parts of the data BFM #100 to #399 are holding configuration data
as well. These BFMs must not be changed during online mode.
After a soft reset is triggered by writing K1 to BFM #25, BFM #25 bit 7 turns ON to indicate that the
module is re-initializing the internal buffers. While this flag is on, TO commands on any BFM are
prohibited and will cause BFM #29 bit 5 to be set to ON.
*2.
Any CAN 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 7
FROM/TO watchdog
timer expired
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 5.8
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 5.3
Bit 9
J1939 mode: no
node address available
Check node address set in BFM #27 and #28.
This bit is set if the node address set in BFM #27 is occupied by another node or if no node address
could be obtained in the address claiming process.
For further information on node address setting, refer to the following section.
Refer to Section 5.9
Bit 10 Not used
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 5.6
Bit 12 Node address change
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 5.9
Bit 13 Not used
Bit 14 Error passive state
This flag shows the CAN error active state/passive state
*2
.
OFF: Error active state
CAN receive message error counter value is in the range of K0 to K127.
ON:
Error passive state
CAN receive message error counter value is K128.
This bit will be reset automatically if the internal error counters return back to below K128.
For the CAN reception error counter, refer to Section 5.14
Bit 15
Message specific error
exists
Message specific error exists.
Check the Message specific error code in BFM #401 to #479.
For the Message specific error code, refer to Section 5.19
Bit
Description
Action
