Mitsubishi Electric MELSEC-F FX3U-J1939 User Manual page 63

FX -J1939 User's Manual
3U
3. ttype (transmission type)
The transmission type defines the trigger for messages to be sent on the network.
All configured transmit messages will be sent when the module is set from configuration to online mode. After
this first transmission, the message will be sent every time the condition of the selected transmission type is
satisfied.
Function Mode [BFM #21]
ttype
K0
K1
K2
K3
K4
K-1
The following table describes the relation between ttype and communication method (transmission of data).
ttype
K-1, K0 to K4
*2. J1939 communication mode does not use remote transmit request (RTR) frames to request certain
information from the network.
The CAN Layer 2 function RTR will not work because although the priority and the source and the
destination node address are part of the J1939 CAN-ID, they might not be known by the requesting
node. Instead, J1939 uses the PGN 59904 (H0EAxx where xx is the destination node number) to
request data from remote nodes:
e.g.
Request PGN 65248 (HFEE0) from the network
PGN 59904 default priority = 06
Requesters node number = nn
CAN-ID Request Message
0x06EA18nn
0x06EAFFnn
K1939
When BFM #20 bit 0 is set to ON, the message is always transmitted.
When BFM #20 bit 0 is set to ON, the message is transmitted.
However, if data has not been changed, it is not transmitted.
When the cycle time set by an interval parameter elapses, the message is always
transmitted.
When the cycle time set by an interval parameter elapses, the message is transmitted.
However, if data has not been changed, it is not transmitted.
The message transmits on one of the following conditions.
• PGN Request
• Message transmit trigger flags
The message transmits when the corresponding message transmit trigger flag in
BFM #1280 to #1284 is set to ON.
Receive message
Communication Method
J1939 Single Frame message
Data Length
1st Data
(DLC)
Byte
3 0xE0
3 0xE0
6.2 [BFM #500 to #973] Configuration Area
Description
*2
For the message transmit trigger flag, refer to Section 5.20
Communication Method
DLC ≤ 8
Point-to-point or BAM
(Multi message)
Data
2nd Data 3rd Data
Byte Byte
0xFE 0x00 24 (H18)
0xFE 0x00 HFF = BC (Broadcast)
6 J1939 Communication Mode
DLC > 8
Destination Node
53
1
2
3
4
5
6
7
8
9
10