
B-64044EN/01 MAINTENANCE 1.HARDWARE
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LED indication of MS and NS (during occurrence of an error)
LED indication Status Error and action
MS Red
NS
◊
Daughter board
failure
The daughter board failed.
Replace the DeviceNet master board.
MS Red
NS
Daughter board
failure
The daughter board failed.
Replace the DeviceNet master board.
Duplicate MAC
IDs
MAC IDs are duplicate.
Verify the following:
→ MAC IDs are not duplicate by check the MAC IDs of all nodes.
MS ◊
NS
Red
Busoff detection Communication stopped because a communication error occurred
frequently.
Verify the following:
→ The communication rates of all nodes are set to the same value.
→ The cable length is appropriate.
→ The cable is not loose or broken.
→ A terminal is placed on only both ends of the main line.
→ There are not much noise.
Network power
failure
Power for communication is not supplied.
Verify the following:
→ Power for communication is properly supplied.
MS ◊
NS
Transmission error Transmission is not completed successfully.
Verify the following:
→ All slaves are turned on.
→ There is no other master on the network.
→ The communication rates of all nodes are set to the same value.
→ The cable length is appropriate.
→ The cable is not loose or broken.
→ A terminal is placed on only both ends of the main line.
→ There are not much noise.
Slave not present No slaves are present.
Verify the following:
→ The slave is turned on.
→ The communication rates of all nodes are set to the same value.
→ The cable length is appropriate.
→ The cable is not loose or broken.
→ A terminal is placed on only both ends of the main line.
→ There are not much noise.
Slave I/O size
mismatch
The slave I/O size setting does not match the setting of the actual
slave.
Verify the following:
→ The slave I/O size setting matches the setting of the actual slave.
MS ◊
NS
Red
I/O communication
error
I/O communication timed out.
Verify the following:
→ The communication rates of all nodes are set to the same value.
→ The cable length is appropriate.
→ The cable is not loose or broken.
→ A terminal is placed on only both ends of the main line.
→ There are not much noise.