Rockwell Automation 1794-OB16D FLEX I/O Diagnostic Modules User Manual - Manual (Page 103)

Publication 1794-UM061A-EN-P - July 2006
Configure your Digital Module on an EtherNet/IP Network 101
device on the network already has the IP address), the EtherNet/IP port of
the module goes into conflict mode, where the module’s:
• OK indicator blinks red.
• network (NET) indicator is solid red.
• front display indicates the conflict (1756-ENBT only).
The display scrolls: ” OK <IP_address_of_this_module> Duplicate IP
<Mac_address_of_duplicate_node_detected> ”
For example: OK 10.88.60.196 Duplicate IP - 00:00:BC:02:34:B4
To correct this conflict, use the instructions in this chapter to change the IP
address of the module. Then cycle power to the module or reset the module
(such as disconnecting the EtherNet/IP cable and reconnecting the cable).
There is also the possibility that two modules can detect a conflict
simultaneously. If this occurs, remove the module that has the incorrect IP
address or correct its conflict. To get the second module out of conflict mode,
cycle power to the module or disconnect its EtherNet/IP cable and reconnect
the cable.
Duplicate detection scenarios
• The behavior of devices that are in conflict over an IP address varies
depending on whether connections have been established to either of
the modules and whether both modules support duplicate IP address
detection:
• If both modules support duplicate IP address detection, the module that
powers up first and uses the IP address, keeps the IP address. The other
module will detect a conflict, give up the IP address, and enter conflict
mode.
• If both modules support duplicate IP address detection and both
modules power up at roughly the same time, both modules give up the
IP address and enter conflict mode.
• If one module supports duplicate IP address detection and a second
module does not, the second module generally keeps it IP address,
regardless of which module obtains the IP address first. The module
that supports duplicate IP address detection will detect the conflict and
give up the IP address.