5 Allocation of Buffer Memories
5.16 [BFM #39] BFM Setting Error Display
42
FX
3U
-J1939 User's Manual
5.16
[BFM #39] BFM Setting Error Display
BFM #29 bit 6 is set to ON if an attempt to write an invalid value into a Buffer Memory is detected.
BFM #39 displays the address of the target BFM of the invalid write attempt. In case an irregular value was
written to more than one BFM, only the address of the first BFM is displayed. When BFM #29 bit 6 is set to
OFF, BFM #39 will be reset to K0.
5.17
[BFM #40 to #48] 64 Bit ECU NAME According to J1939-81
The ECU name is unique for every module in the network and is used for identification. The ECU Name
contains 64 bits. 62 of those bits are defined as shown in the following table.
The remaining 2 bits are reserved by SAE. FX
3U
-J1939 sets the reserved bits automatically to OFF.
*1.
FX
3U
-J1939 sets the Industry Group to group 5 (Industrial, Process Control, Stationary Equipment) by
default.
*2.
FX
3U
-J1939 sets the Vehicle System and Function to "not available" as defined in SAE J1939
specification for undefined/unknown Vehicle Systems and Functions.
*3.
The Vehicle System Instance, Function Instance and ECU Instance should be set to K0 for the first
object of this kind or if only one object exists in the whole network.
Industry Group
Defines the application field or general environment. Most applications of the FX
3U
-J1939 will be in the
"Industrial, Process Control, Stationary Equipment" which equals the default K5.
Vehicle System
In combination with the Industry group, the Vehicle system is used to identify a unit with several functions. In
the case of Industry Group 5, this could be a generator set. The exact function within the generator set unit
will be assigned by the function field. The default value K127 defines the Vehicle System as "Not available" or
"Not yet defined".
Vehicle System Instance
The Vehicle System Instance identifies a certain entity of a Vehicle System in case there is more than one in
the same network.
Function
The Function field defines the particular task of a certain device more specifically. The Default value K255
defines the Function as "Not available" or "Not yet defined".
A device of Industry group K5, Vehicle System K0, Function K129 would identify the generator set controller
(within a generator set system).
Function Instance
The Function Instance identifies a certain entity of a Function in case there is more than one in the same
network.
ECU instance
The ECU Instance identifies a certain entity of an ECU in case there is more than one electronic control unit
with the same function in the same network.
BFM No.
Field name
Length
Default value
Remarks
BFM #40
Industry Group
3 bit
K5
*1
SAE defined
BFM #41
Vehicle System
7 bit
K127 (H7F)
*2
SAE defined
BFM #42
Vehicle System Instance
4 bit
K0
*3
-
BFM #43
Function
8 bit
K255 (HFF)
*2
SAE defined
BFM #44
Function Instance
5 bit
K0
*3
-
BFM #45
ECU instance
3 bit
K0
*3
-
BFM #46
Manufacturer Code
11 bit
K2047 (H7FF)
SAE defined
BFM #47
Identity Number (LW)
21 bit
H1FFFFF
-
BFM #48
Identity Number (HW)
