CJ1W-EIP21 Omron, CJ1W-EIP21 Datasheet - Page 134

• Manufacturer Part Number: CJ1W-EIP21
• Description: Ethernet I/P Module
• Manufacturer: Omron

Specifications of CJ1W-EIP21

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5-3
5-3-1
Communications Services
That Require Global
Addresses for EtherNet/IP
Units and built-in
EtherNet/IP ports
106
Private and Global Addresses
Intranet
Private and Global Addresses
Private and Global Addresses
Firewall
IP router
Global address
Private address
Intranet
Private address
There are two kinds of IP addresses, private and global.
Generally, as shown below, global addresses in the intranet are allocated only
to IP routers (such as broadband routers) interfacing with the Internet. All
other nodes in the intranet, including the EtherNet/IP Unit or built-in EtherNet/
IP port, are allocated private addresses.
A global address is required for the IP addresses of the EtherNet/IP Units and
built-in EtherNet/IP port when the following communications services are
used over the Internet.
• Global addresses: These are IP addresses that connect directly to the
• Private addresses: These are IP addresses for Intranet (LAN) use, and
Ethernet (EtherNet/IP)
• FINS communications services
• Explicit message communications services
Firewall
IP router
PLC
Internet
Private address
Private address
PLC
Internet. Allocated by application to NIC, each
address is unique in the world, and as many as
4.3 million can be allocated worldwide.
cannot connect directly to the Internet. Frames that
include private IP addresses are restricted by the
router from being sent outside the LAN.
Global address
(required)
Ethernet (EtherNet/IP)
Personal computer,
CX-Programmer, etc.
Personal computer,
CX-Programmer, etc.
PLC
Private address
Private address
Not output to Internet
Not output to Internet
Section 5-3