Rockwell Automation 193-DNENCATR EtherNet/IP Communications Auxiliary User Manual - Manual (Page 23)

Rockwell Automation Publication 193-UM014B-EN-P December 2011 23
Chapter 2
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.
Table 4 - Device Conflict over Duplicate IP Addresses
DNS Addressing To further qualify a module’s address, use DNS addressing to specify a host name
for a module, which also includes specifying a domain name and DNS servers.
DNS addressing makes it possible to set up similar network structures and IP
address sequences under different domains.
DNS addressing is only necessary if you refer to the module by host name, such as
in path descriptions in MSG instructions.
To use DNS addressing, perform this procedure.
1. Assign a host name to the module.
2. Configure the module's parameters.
3. In addition to the IP address, subnet mask, and gateway address, configure
a host name for the module, domain name, and primary/secondary DNS
server addresses.
Electronic Data Sheet (EDS)
File Installation Before the EtherNet/IP Communications Auxiliary is configured to
communicate on an EtherNet/IP network, it must be registered to the software
that configures the network (e.g., Rockwell Automation RSLinx Classic and
RSNetWorx for EtherNet/IP software). A user registers the module by installing
an EDS file. The EDS file for the EtherNet/IP Communications Auxiliary can
be obtained from one of two locations:
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 the modules 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.
NOTE:
Contact the network administrator ro have a host name assigned. Valid host
names should be IEC-1131-3 compliant.