Layer 2 Message Mode - Mitsubishi Electric MELSEC iQ-R Series User Manual

Layer 2 message mode

The following is troubleshooting by symptom in the 11-bit CAN-ID Layer 2 message mode and 29-bit CAN-ID Layer 2
message mode.
Cannot send/receive Layer 2 messages
The following table lists the actions to be taken if Layer 2 message communication is not possible.
Check item
Is the CAN bus cable connected firmly to the transmission cable terminal
block of the RJ71CN91?
Are terminating resistors connected to the both ends of the network?
Is the baud rate the same at all CANopen nodes in the network?
When communication was executed, were one or more other stations capable
of communication connected?
Is the RJ71CN91 function mode set to 11-bit CAN-ID Layer 2 message mode
or 29-bit CAN-ID Layer 2 message mode?
Is the 11-bit CAN-ID Layer 2 message mode or 29-bit CAN-ID Layer 2
message mode selected according to the format used?
Are parameters set correctly for the RJ71CN91?
Is 'Layer 2 online mode status' (X3) turned on?
Is the RJ71CN91 in the bus off state?
Is 'Data exchange request' (Y1) turned on?
Is the send data changed from the previous transmission when "Transmission
type" is Event (COS) or Cycle (COS)?
Is 'Message transmit trigger request' (Y4) turned on when the transmission
type is Transmit trigger?
*1 When the device type of other stations is RJ71CN91, communication is disregarded during Layer 2 offline mode.
5 TROUBLESHOOTING
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5.4 Troubleshooting by Symptom
Action
Connect the CAN bus cable firmly to the transmission cable terminal block.
Connect terminating resistors to both ends of the network.
Ensure that the baud rate is the same at all CANopen nodes in the network.
• Execute communication with one or more other stations connected.
• Execute communication after making one or more other stations capable of
communication. (If the device type of other stations is RJ71CN91, activate
*1
the Layer 2 online mode.)
Set the RJ71CN91 function mode to 11-bit CAN-ID Layer 2 message mode or
29-bit CAN-ID Layer 2 message mode.
Also, ensure that the 11-bit CAN-ID Layer 2 message mode or 29-bit CAN-ID
Layer 2 message mode is selected according to the format used.
Set parameters correctly for the RJ71CN91.
Turn on 'Layer 2 online mode request' (Y3).
Turn on 'Layer 2 online mode request' (Y3) to bring the RJ71CN91 into the
Layer 2 online mode again.
Turn on 'Data exchange request' (Y1) to update send/receive data.
Change the send data from the previous transmission, and turn on 'Data
exchange request' (Y1).
In 'Message transmit trigger flags (Un\8400 to Un\G8402), turn on the bit
corresponding to the sending message slot and turn on 'Message transmit
trigger request' (Y4) to send data.