Rockwell Automation 193-ETN E1 Plus EtherNet Side Mount Module User Manual - Manual (Page 25)

Rockwell Automation Publication 193-UM012B-EN-P - June 2011 25
Chapter 3
module. You might have to disconnect from the uplink to set the address and
configure the module to retain its static address before reconnecting to the
uplink. This is not a problem if you have node names configured in the module
and leave DHCP enabled.
Duplicate IP Address
Detection When you change the IP address or connect the module to an EtherNet/IP
network, the module checks to make sure that the IP address assigned to this
module does not match the address of any other network device. If the module
determines that another device on the network with a matching IP address, the
EtherNet/IP port of the module goes into conflict mode.
• NETWORK STATUS LED indicator is solid red.
To resolve 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 modules by
disconnecting and then reconnecting the EtherNet cable.
Two modules could possibly detect a conflict simultaneously. If this occurs,
perform this procedure.
1. Remove the module with the incorrect IP address and correct its conflict.
2. Cycle power or disconnect the EtherNet cable from the second module
and reconnect it.
Behavior of Modules With Duplicate IP Addresses
Devices in conflict over an IP address behave differently depending on whether
connections have been established to either of the modules and whether both
modules support duplicate IP address detection.
ATTENTION: The E1 Plus EtherNet/IP module must be assigned a
fixed network address. The IP address of this module must not be
dynamically provided.
Failure to observe this precaution may result in unintended
machine motion or loss of process control.
Table 5 - Device Conflict Over Duplicate IP Addresses
If Then
Both modules support duplicate IP address detection The first started module uses and retains its IP address.
The other module will detect a conflict, give up the IP address and enter conflict mode.
Both modules support duplicate IP address detection
and are started at roughly the same time One of them surrenders the IP address and enters conflict mode.
One module supports duplicate IP address detection
and a second module does not The second module generally keeps its IP address, regardless of which module first obtains the
IP address.
The module that supports duplicate IP address detection will detect the conflict and give up the
IP address.