12   Troubleshooting
12 - 38
NX-series EtherNet/IP Coupler Unit User’s Manual (W536)
Event name IP Address Duplication Error Event code 84500000 hex
Meaning The same IP address is used more than once
Source EtherNet/IP Source details EtherNet/IP 
Coupler Unit
Detection 
timing
After link is 
established
Error 
attributes
Level Minor fault Recovery Cycle power to 
the EtherNet/IP 
Coupler Unit or 
restart the 
Slave Terminal.
Log category System
Effects
User program
Continues. Operation When Fail-soft Operation Is Set to Fail-soft
• EtherNet/IP Coupler Unit, EtherNet/IP Communi-
cations
Ethernet communication stops.
•NX Bus
(1) NX Safety Standalone mode
I/O refreshing to the NX Units continues.
(2) Remote I/O mode.
I/O refreshing to the NX Units stops.
Messages cannot be sent to the NX Units in the 
Slave Terminal.
When Fail-soft Operation Is Set to Stop
• EtherNet/IP Coupler Unit, EtherNet/IP Communi-
cations
Ethernet communication stops.
•NX Bus
(1) NX Safety Standalone mode
I/O refreshing to the NX Units stops.
(2) Remote I/O mode.
I/O refreshing to the NX Units stops.
Messages cannot be sent to the NX Units in the 
Slave Terminal.
Sys-
tem-defined 
variables
Variable Data type Name
None --- ---
Cause and 
correction
Assumed cause Correction Prevention
The IP address of the EtherNet/IP 
port is also used as the IP address 
of another node
Perform either of the following and 
then cycle the power supply to the 
EtherNet/IP Coupler Unit or restart 
the EtherNet/IP Coupler Unit.
• Check the IP addresses of other 
nodes and correct the IP 
address settings so that the 
same address is not used by 
more than one node.
• Remove the node that has the 
duplicate IP address from the 
network.
Set the IP address of the Ether-
Net/IP Coupler Unit so that the 
same address is not used by 
another node.
Attached 
information
Attached information 1: Duplicated IP address (example: C0A8FA01 hex = address 192.168.250.1)
Precautions/
Remarks
When the EtherNet/IP Coupler Unit is started or the link of the EtherNet/IP port is established, an ARP 
request is broadcasted with the set IP address. A duplicated address error occurs if there is an ARP 
response from another node for this request.