Private and Global Addresses
5-3-3
EtherNet/IP Unit with a Global Address
Communications
over Internet
Intranet
Global address
IP router
Firewall
Communications
in intranet
Conditions for Using
Communications
Applications
Intranet
Firewall
IP router
Internet
Private address
Ethernet (EtherNet/IP)
PLC
EtherNet/IP Unit: Global address
Communications applications can be used over the Internet under the follow-
ing conditions:
■
FINS Communications Service
• A device such as a personal computer (a FINS application, including the
CX-Programmer) can connect online and communicate over the Internet
with an EtherNet/IP Unit or built-in EtherNet/IP port that has a global
address.
• FINS/TCP is recommended as the FINS communications service
method.
FINS/TCP is more reliable than FINS/UDP in terms of communications
errors involving IP routers.
• The IP address table method is used as the IP address conversion
method of the EtherNet/IP Unit or built-in EtherNet/IP port.
• The TCP port number to be used for FINS/TCP cannot be used if prohib-
ited by a firewall in the communications path.
■
Explicit Message Communications Service
• A device such as a personal computer (a CIP application including the
Network Configurator) can connect online and communicate over the
Internet with an EtherNet/IP Unit or built-in EtherNet/IP port that has a
global address.
FINS/TCP client computer
with CX-Programmer, etc.
or
CIP client computer with
Network Configurator, etc.
Ethernet (EtherNet/IP)
Global address
(required)
Section 5-3
Private address
Not output to Internet
Not output to Internet
Private address
109