Mitsubishi Q01CPU User Manual page 371

12
TROUBLESHOOTING
(From previous page)
Has the hub
or router discarded messages
because of its too-small packet buffer
capacity? (Consult your network
administrator.)
NO
Is communication of
a device other than QnUDE(H)CPU
unstable? (Consult your network
administrator.)
NO
Have many
unnecessary broadcast data
been received? (See Connection
status in Ethernet
diagnosis.)
NO
Is Ethernet communication load on
QnUDE(H)CPU too high?
NO
Is any interrupt program used?
NO
Check the communications referring to the following.
Section 12.2.27
When Ethernet communication with the target device is not available
YES
YES
YES
Unnecessary broadcast data have been highly loaded.
Increase service process time for QnUDE(H)CPU.
Consult your network administrator, and check the network condition.
Identify a broadcasting device, and restrict the broadcast data volume.
(Devices such as computers or routers may broadcast data.)
Use filtering of broadcast data with a router to prevent QnUDE(H)CPU from
receiving them.
Separate the network where frequent broadcasts occur from the network
containing QnUDE(H)CPU.
YES
YES
12.2.29 When Ethernet communication with CPU module is slow or unstable
Consult your network administrator and check the hub
and router.
Use a hub or router that has a large packet buffer
capacity.
Is Ethernet
NO
communication stabilized?
Consult your network administrator and check the
network condition.
Take actions against noise to reduce communication
3
errors. *
Check the traffic, and if a high traffic is a cause of the
problem, take actions for it.
Is Ethernet
NO
communication stabilized?
Is Ethernet
NO
communication stabilized?
Reduce the Ethernet communication load on QnUDE(H)CPU.
Increase the service time of QnUDE(H)CPU.
Reduce the number of connected devices.
Reduce the connection setting value.
Reduce the communication frequency per connection
and data volume.
Is Ethernet
NO
communication stabilized?
Reduce the frequency and process time of the interrupt
program.
Is Ethernet
NO
communication stabilized?
12.2 Troubleshooting
9
10
YES
11
YES
12
YES
YES
YES
Completed
12
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