3
Ethernet Unit Function Guide Section 1-1
Connecting through
Multiple Segments Use the TCP/IP version of the FINS communications service (i.e., FINS/TCP).
FINS/TCP is a new function supported by these Ethernet Units (CS 1W-
ETN21 and CJ1W-ETN21). It provides automatic recovery at the TCP/IP layer
from communications errors (such as packet loss) that occur during multilevel
routing. For CX-Programmer (version 4.0 or higher), FINS/TCP can be used
to directly connect to the PLC online. To use lower versions of the CX-Pro-
grammer with FINS/TCP, use FinsGateway (version 2003 or higher) as per-
sonal computer middleware.
Using Media with
Unreliable Connections,
Such as a Wireless LAN
Use the TCP/IP version of the FINS communications service (i.e., FINS/TCP).
FINS/TCP is a new function supported by these Ethernet Units (CS 1W-
ETN21 and CJ1W-ETN21). It provides automatic recovery at the TCP/IP layer
from communications errors (such as packet loss) resulting from unreliable
connections. For CX-Programmer (version 4.0 or higher), FINS/TCP can be
used to directly connect to the PLC online. To use lower versions of the CX-
Programmer with FINS/TCP, use FinsGateway (version 2003 or higher) as
personal computer middleware.
Connecting from a
Personal Computer with a
Dynamic Private IP
Address
Depending on whether or not the connection will be within the s ame segment,
either use an IP address conversion method for dynamic IP addresses in th e
UDP/IP version of the FINS communications service or use the TCP/IP ver-
sion of the FINS communications service.
It is possible to connect online to a PLC using the CX-Pr ogrammer from a
computer serving as a temporarily connected node or a per manent DHCP cli-
ent.
For CX-Programmer (version 4.0 or higher), FINS/TCP can be used to directly
connect to the PLC online. To use lower versions of the CX-Programmer with
FINS/TCP, use FinsGateway (version 2003 or higher) as personal computer
middleware.