Mitsubishi Electric MELSEC-F FX3U-CAN User Manual page 175

FX -CAN User's Manual
3U
2. When receiving messages
The CAN-ID, RTR/new/DLC and data bytes of each message are as follows.
Note
In case more than one ID can pass the filter set in BFM #1100 to #1267, the received CAN-ID might change
and will always display the CAN-ID, DLC and data of the latest received message.
1) CAN-ID
The source CAN-ID of the received Layer 2 message is stored. CAN-ID is as follows corresponding to the
function mode to be used.
Function Mode
11 bit CAN-ID Layer 2 Mode
29 bit CAN-ID Layer 2 Mode
*1. The "n" corresponds to the Layer 2 message number.
2) RTR/new/DLC
High Byte/Low Byte
High byte
Low byte
*2. If bit 8 of the RTR/new/DLC is ON, a new message including new data has been received and
stored. If bit 9 is ON but bit 8 is OFF, the same message (same ID, DLC and data) has been
received. If bit 10 is ON, at least one more message has been stored in this message buffer while
bit 8 was ON which caused an overflow condition.
Flags
RTR / new / DLC
New data (bit 8)
New frame (bit 9)
Overflow (bit 10)
3) Data bytes
The data received of length specified by DLC is stored.
In case the received DLC is less than 8, unused data bytes are set to H00.
→ For Layer 2 message configuration in BFM #1100 to #1267, refer to Section 9.3
CAN-ID is stored in the 11 bits, bit 0 to 10, in the CAN-ID n
In this function mode, CAN-ID n
CAN-ID is stored in the 29 bits, bit 0 to 28, in the CAN-ID n
*1
Handle CAN-ID n LW and CAN-ID n
H00: New data is not received.
Bit 8: ON when new data is received.
Bit 9: ON when new frame is received.
*2
Bit 10: ON when overflowing.
Data length count (DLC) of the received CAN frame.
New frame New frame
no new data new data
OFF
ON
OFF OFF
→ For the function mode, refer to Section 6.5
Description
*1
*1
HW does not used.
*1
*1
HW by 32 bit instructions.
Description
Receive messages only
New frame New frame
no new data
overflow occur overflow occur
ON OFF
ON ON
ON
9 CAN Layer 2 Mode
9.1 Receive/Transmit Process Data
LW.
*1
LW and CAN-ID n HW.
new data No data received
ON - (Do not care)
ON OFF
ON - (Do not care)
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