Table of Contents
Advertisement
FX
-J1939 User's Manual
3U
5.9
[BFM #27] Node Address (Address Claim Start Address)
Sets the node address within the J1939 network. A node address written by a TO instruction, etc. into BFM
#27 will be effective after the next power cycle or BFM #25 bit 0 reset.
The actual node address is always displayed in BFM #28. The address claiming process starts at the address
set in BFM #27 after power cycle or BFM #25 bit 0 reset. If the module is set from online to offline and back to
online, it will try to acquire the last used address shown in BFM #28.
If this address is not available, another address is claimed. When the address claiming process is successful,
BFM #28 will display the address occupied by the FX
Caution
• The address range K0 to K127 and K208 to K255 is assigned/reserved by SAE J1939. If the user sets one
of these addresses, it is their responsibility to ensure proper network behavior.
e.g. It may be useful to set the FX
programming. But if the "Engine address" is used by the FX
motor), the network will be adversely affected.
• Any new valid value written to BFM #21, #24, #25 bit 2, #26 or #27 is automatically stored to 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
• The node address is not used in Layer 2 mode; any write access to this BFM will be ignored. The value is
not changed or stored to non volatile memory as long as the module is in Layer 2 mode.
• If the node address is the result of an address claiming procedure, the address is displayed in BFM #28 but
not stored to Flash ROM. After the next power ON or reset (BFM #25 bit 0), the FX
negotiate for a node address again and might obtain another address.
• If an invalid node address is written to BFM #27, the BFM will keep its former value and BFM #29 bit 12 will
be set.
• If the address set in BFM #27 is not a dynamic address, bit 2 in BFM #25 is set to OFF.
• If during the address claiming process an "address conflict" occurs (two nodes want to use the same node
number), the node address number is assigned to the node with the higher priority. The other node must
continue address claiming to find another free address.
The priority of a node depends on the node's "ECU name." If all other fields of the "ECU name" are same,
the smaller value of "Function Instance" in the "ECU name" indicates higher priority.
For further information on ECU name, refer to following section.
When a fix node address is required
Set the node address by using one of the following methods.
• Set BFM #25 bit 2 to OFF, and set an address in BFM #27
• Start the address claim procedure once, when an address is obtained:
1) Read the obtained address from BFM #28
2) Set BFM #25 bit 2 to OFF.
Otherwise, address claiming might start from the new address after the next power on or reset.
3) Write the address read from BFM #28 back to BFM #27.
The address will be stored to Flash ROM.
5.9 [BFM #27] Node Address (Address Claim Start Address)
-J1939.
3U
-J1939 address to an "engine" address to simulate the motor during
3U
3U
5 Allocation of Buffer Memories
-J1939 in a real application (including the
-J1939 will start to
3U
Refer to Section 5.17
1
2
3
4
5
6
7
8
9
10
39
Advertisement
Table of Contents
