Rockwell Automation 1794-OB16D FLEX I/O Diagnostic Modules User Manual - Manual (Page 102)

Publication 1794-UM061A-EN-P - July 2006
100 Configure your Digital Module on an EtherNet/IP Network
This sets the IP address in the hardware. This IP address should be the
same IP address you assigned under the General tab.
On this screen, you can also specify port speed (10 Mbps or 100 Mbps)
and duplex mode (autonegotiate, half duplex, or full duplex). All
modules on the same subnet must be configured for the same port
speed and duplex mode.
Using DHCP software to set the IP address
DHCP (Dynamic Host Configuration Protocol) 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 your module. A BOOTP
client, such as the EtherNet/IP modules, can boot 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 you use. Check with your system
administrator to see if your DHCP package supports BOOTP commands and
manual IP allocation.
Duplicate IP Address
Detection
These EtherNet/IP modules (and their future revisions) support duplicate IP
address detection:
• 1756-ENBT, firmware revision 3.2 and greater
• 1788-ENBT, firmware revision 2.1 and greater
• 1756-EWEB, firmware revision 2.2 and greater (For more information
about this module, see the EtherNet/IP Web Server Module User
Manual, publication
ENET-UM527 .)
When you change the IP address or connect one of these modules to an
EtherNet/IP network, the module checks to make sure that the IP address
assigned to this module is not the same as that for any other device already on
the network. If the module determines that there is a conflict (some other
ATTENTION
The 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.