Layer 2 Message Transmission And Receive - Mitsubishi Electric MELSEC iQ-R Series User Manual

1.11

Layer 2 Message Transmission and Receive

Layer 2 messages are used to send/receive data between CAN nodes.
Different from CANopen nodes, CAN nodes do not have node IDs, so they send/receive data based on the CAN-ID set in
each message. CAN nodes can also request other nodes to send data by RTR.
Layer 2 messages can send/receive messages when the own node is in Layer 2 online mode.
CAN node
CAN-ID = A
(2)
CAN-ID = B
(3)
CAN-ID = B
(2)
(1) Data transmission
(2) Data reception
(3) RTR
(4) RTR response
: Data frame
: Remote frame
The following table lists the messages used for data communication and their execution methods.
: Available, : Not available
CAN message
Data transmission
RTR
RTR response
Data reception
*1 When sending data as a Layer 2 message, the same message can be used for both data transmission and RTR response.
CAN node
(1)
(4)
Execution method
CIF Layer 2 message
*1
 
 
*1
 
 
Description
Sends data to another node.
Requests another node to send data.
Sends data in response to RTR from another node. (Select either
automatic response or manual response.)
Receives data from another node.
1.11 Layer 2 Message Transmission and Receive
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1 FUNCTIONS
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