Installation guide

Network Infrastructure for EtherNet/IP™
6-76
Infrastructure Application Scenarios
6.4 Enterprise-Connected and Integrated Control Systems
There are often requirements for enterprise or plant-wide networks to selectively access control system
data. Higher level plant systems often contain servers used to download the control programs necessary to
reconfigure flexible manufacturing systems. Plant-wide systems may also carry video monitoring, MRP,
and other production data that needs to be processed separately from real-time critical control traffic on
the plant floor. There are two approaches to allowing this selected access to occur while isolating the
plant-floor network from the plant backbone.
6.4.1 Networks Connected via CIP Gateways
An EtherNet/IP network can be connected to the enterprise network via a gateway. A typical example of a
gateway is a programmable logic controller with multiple EtherNet/IP ports acting as a CIP gateway as
shown in Figure 6-10. In such a network, all of the implicit real-time control traffic is isolated to one or
more separate EtherNet/IP ports. Since EtherNet/IP and enterprise networks are connected via a CIP
gateway, there is no propagation of unwanted traffic from the EtherNet/IP network into the enterprise
network and vise versa. Therefore, there is no difference, from the EtherNet/IP infrastructure point of
view, between enterprise-connected and isolated EtherNet/IP networks. This approach requires that any
data transfer between networks be done through PLC programming or setup.
Figure 6-10 EtherNet/IP and Enterprise Networks Connected via a CIP Gateway.
Enterprise
Backbone
Enterprise layer 2 switch, layer 3
switch
or route
r
PLC acting as CIP
Gateway
Industrial Ethernet
Switch
I/O
I/O
PLC Module 1 has
IP address A
PLC Module 2 has
IP address B
I/O