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FX
-J1939 User's Manual
3U
5.
Allocation of Buffer Memories
5.1
Buffer Memories (BFM) Lists
Caution
• Do not access buffer memory (BFM) that is marked as "not used" (Ex. BFM #0 to #19, #23, #31 to #34, #49
to #99, #400, #480 to #499, etc.) by FROM/TO instructions, etc. Accessing these buffer memories may
cause abnormal behavior of the FX
• When BFM #21, #24, #25 bit 2, #26 or #27 is written to, FX
BFM in the built-in flash ROM. The maximum number of writes to the built-in flash ROM is 10,000 times.
Therefore, when creating a program, do not frequently write to such buffer memories.
Note
• When writing to a BFM that contains any bits marked as "reserved" (Ex. BFM #20 bit 1 to bit 15, BFM #22
bit 3 to bit 15, etc), set such bits to OFF.
Setting these flags to ON may cause abnormal behavior of the FX
• The state of BFM #40 to #48, #100 to #399, #500 to #973, #1100 to #1267, #1900 to #1927, #3000 to
#3879 is stored in the built-in flash ROM by turning ON BFM #22 bit 0. The buffer memories that are stored
depend on the function mode (BFM #21).
For further information, refer to the following section.
Therefore, when creating a program, do not frequently switch BFM #22 bit 0 from OFF to ON.
BFM No.
BFM #0 to #19
BFM #20
BFM #21
BFM #22
BFM #23
BFM #24
BFM #25
BFM #26
BFM #27
BFM #28
BFM #29
BFM #30
BFM #31 to #34
BFM #35
BFM #36
BFM #37
BFM #39
BFM #40 to #48
BFM #49 to #99
BFM #100 to #399
BFM #400
BFM #401 to #479
BFM #480 to #499
BFM #500 to #973
32
-J1939.
3U
Description
Not used
Data exchange control
Function mode
Save/Restore configuration
Not used
Baud rate
Communication status
FROM/TO Watchdog ( 10 ms)
Node address (address claim start address)
Node address (current address)
Error status
Module ID code
Not used
CAN transmission error counter
CAN reception error counter
Baud rate display ( 0.1 kbps)
BFM setting error display
64 bit ECU NAME according to J1939-81
Not used
Data (read/write)
Not used
Message error code list
Not used
J1939 message configuration area
5 Allocation of Buffer Memories
5.1 Buffer Memories (BFM) Lists
-J1939 stores the state of the corresponding
3U
-J1939.
3U
Refer to Section 5.5
Stored to
Default
Read/
Flash
value
Write
ROM
-
-
-
K0
R/W
-
K1939
R/W
K0
R/W
-
-
-
-
K250
R/W
*1
K4
R/W
K20
R/W
K128
R/W
K254
R
-
K0
R/W
-
K7180
R
-
-
-
-
K0
R
-
K0
R
-
K2500
R
-
K0
R
-
*2
-
R/W
-
-
-
*2
K0
R/W
-
-
-
K0
R/W
-
-
-
-
*2
-
R/W
Reference
-
Section 5.3
Section 5.4
Section 5.5
-
Section 5.6
Section 5.7
Section 5.8
Section 5.9
Section 5.10
Section 12.2
Section 5.12
-
Section 5.13
Section 5.14
Section 5.15
Section 5.16
Section 5.17
-
*3
-
Section 5.19
-
Section 6.2
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