Mitsubishi Electric MELIPC MI5000 Series User Manual page 213

The transmission status is disconnected or unconfirmed
If the CC-Link IE Field Network Basic diagnosis transmission status is disconnected or unconfirmed, then check the following
items.
Check Ethernet
Check the following items.
Check item
Are master station/slave station IP addresses and subnet masks correctly set?
Is there any duplication of IP addresses?
Are there any devices with IP addresses that are the same as master station/
slave stations within the same network address?
Do master station and slave station network addresses match?
Is access blocked?
In the following settings, is access from the slave station blocked?
• [Basic Parameter]  [External Device Cooperate Applicable Settings] 
[Security Settings]  [IP Filter Settings]
Before the error occurred, has the device on the circuit (slave station, hub,
etc.) been exchanged with a device with the same IP address from before the
exchange?
*1 Devices on Ethernet retain ARP cache correspondence tables for IP addresses and MAC addresses. Accordingly, replacing devices on
the circuit with those that have the same IP address means that the MAC address retained in the ARP cache and that of the replaced
device will not match, which may prevent normal communications. ARP cache is updated after a device reset or after a set time. Note
that this time depends on the device.
Confirm CC-Link IE Field Network Basic
Check the following items.
Check item
In the CC-Link IE Field Network Basic link scan time, is the "Current" value set
to "0 ms"? ( Page 90 CC-Link IE Field Network Basic diagnostics)
Corrective action
Correct the master station/slave station IP addresses and subnet masks.
Check whether a device with the same IP address as the IP address of this
product is connected, and then change to an IP address that does not overlap.
Change master station/slave station IP addresses to addresses that do not
overlap.
• Correct IP address and subnet masks so the master station and slave
station IP addresses match.
• Correct so the master station/slave station subnet masks have the correct
values and match.
Review firewall and other security settings.
Review settings so access from the slave station IP address and UDP
communications pass.
If a device on the circuit (slave station, hub, etc.) was exchanged with a device
with the same IP address from before the exchange, take one of the following
measures.
• Wait until the ARP cache update has run. (Wait periods depend on the
*1
device.) )
• Restart all devices on the line.
Corrective action
Correctly wire the Ethernet cable.
Appendix 1 Troubleshooting by Symptom
A
APPX
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