Installation guide

Network Infrastructure for EtherNet/IP™
6-77
Infrastructure Application Scenarios
6.4.2 Networks Integrated with Routers (or Layer 3 Switches)
An enterprise-integrated EtherNet/IP network is fully integrated into the enterprise network infrastructure.
This type of interconnection results in a single, integrated network. The addressing practices, security
policies, network management techniques, and “change control” procedures of the enterprise network and
the control system portions of that network must be harmonized.
6.4.3 Two Types of Integration
The type of integration—non-interlock connected or interlock connected—used depends on whether or
not implicit message traffic will traverse the corporate backbone network. These two integration types are
representative of large corporate installations where the corporate backbone and the plant-floor
environments span a large area. Non-interlock is quite common as it allows selected data transfers, but
keeps the real-time data isolated to a particular area of the plant floor and isolated from other plant traffic
that may affect control system performance.
6.4.3.1 Non-Interlock Connections
A non-interlock connection is used if there is no implicit message traffic traversing the backbone network.
As shown in Figure 6-11, the only traffic being passed is supervisory, programming, monitoring, and so
forth. There is no real-time data being passed. There is no CIP gateway in use; the backbone is connected
directly to the plant-floor network infrastructure. There may be implicit messaging within the local
network zone, but it is not meant to pass into the backbone network. Protection may be needed to prevent
multicast traffic from adversely affecting the backbone environment. Connection points to the backbone
may be a Layer 2 switch (VLANs, Layer 2 filtering), a Layer 3 switch (Access Control Lists, Layer 2/3
filtering), or a router (ACLs, Layer 2/3 filtering, firewall function).
Figure 6-11 Example of a Non-interlocked Integrated Network.
Plant Floor
Enterprise
Network
Layer2
switch,
Layer3 switch
or router
Industrial
switch
Industrial
switch
PLC
I/O
I/O I/O
Corporate
Backbone
Supervisory and
non-implicit
control traffic