Rockwell Automation 1756-Enxxx_Ewxxx EtherNet/IP Modules Installation Instructions User Manual

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Rockwell Automation Publication ENET-IN002F-EN-P - January 2014

Chapter 2 Install a 1768 EtherNet/IP Communication Module

Use DHCP Software

Dynamic Host Configuration Protocol (DHCP) software automatically assigns
IP addresses to client stations logging onto a TCP/IP network. DHCP is based
on BOOTP and maintains some backward compatibility. The main difference is
that BOOTP allows for manual configuration (static), while DHCP allows for
both static and dynamic allocation of network addresses and configurations to
newly attached modules.

Be cautious when using DHCP software to configure a module. A BOOTP
client, such as the EtherNet/IP communication modules, can start from a DHCP
server only if the DHCP server is specifically written to also handle BOOTP
queries. This is specific to the DHCP software package used. Consult your
system administrator to see if a DHCP package supports BOOTP commands
and manual IP allocation.

Set the Network IP Address with RSLinx Software or the Studio 5000
Environment

This table describes when to set the network IP address with RSLinx or
RSLogix 5000 software.

Consider these factors when you determine how to set the network IP address:

• Network isolation from or integration into the plant/enterprise network

• Network size - For large networks, isolated networks, it might be more

convenient and safer to use a BOOTP/DHCP server rather than
the Studio 5000 environment or RSLinx software. The BOOTP/DHCP
server also limits the possibility of assigning duplicate IP addresses.

• Company policies and procedures dealing with plant floor network

installation and maintenance

• Level of involvement by IT personnel in plant-floor network installation

and maintenance

• Type of training offered to control engineers and maintenance personnel

ATTENTION: The EtherNet/IP communication 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.

Conditions

Software to Use

Page

• A BOOTP server is not available.

• The EtherNet/IP communication module is connected to another

NetLinx network.

RSLinx

The Studio 5000 project is online with a controller that communicates to or

through the EtherNet/IP communication module.

Studio 5000 environment
(Logix Designer application)