DNS Addressing

You can also use DNS addressing to specify a host name for a controller, a domain name, and DNS servers. DNS addressing makes it possible to configure similar network structures and IP address sequences under different domains.
IMPORTANT:
Safety Considerations
Safety connections are not allowed to use host names (this requires DNS lookup, which is not allowed for Safety I/O).
  • Safety devices on
    EtherNet/IP™
     networks (such as a safety-enabled controller in a safety project) do not present the host name parameter.
  • Standard devices (not safety enabled) do present the host name parameter, regardless of whether the project is safety or standard. When used in a standard project, the only connections are standard consumed tags, so the controller presents the host name parameter.
DNS addressing is necessary only if you refer to the controller by host name, such as in path descriptions in MSG instructions.
To use DNS addressing, follow these steps.
  1. Assign a host name to the controller.
    A network administrator can assign a host name. Valid host names must be IEC-1131-3 compliant.
  2. Configure the controller parameters.
  3. Configure the IP address, subnet mask, gateway address, a host name for the controller, domain name, and primary/secondary DNS server addresses.
    In the DNS server, the host name must match the IP address of the controller.
  4. In the Logix Designer application, add the controller to the I/O configuration tree.
    IMPORTANT:
    Remember the following:
    • If a child module resides in the same domain as its parent module, type the host name. If the domain of the child module differs from the domain of its parent module, type the host name and the domain name (hostname.domainname).
    • You can also use DNS addressing in a module profile in the I/O configuration tree or in a message path. If the domain name of the destination module differs from the domain name of the source module, then use a fully qualified DNS name (hostname.domainname). For example, to send a message from EN2T1.location1.companyA to EN2T1.location2.companyA, the host names match, but the domains differ. Without the entry of a fully qualified DNS name, the module adds the default domain name to the specified host name.
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal