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FINS/TCP Method Section 7-4
Even if the keep-alive function is not specified at the Ethernet Unit, a re-
sponse is sent for checks sent from other nodes. If the power is turned
OFF to the host application (e.g., personal computer) while a connection
is established, the connection is no longer required, but will remain open
until explicit close processing is performed. If the keep-alive option is se-
lected, the connection is checked periodically, and close processing is
performed if a response is not received. For normal operations, select the
keep-alive option.
(2) Keep-alive Monitor Time Setting
The liveness checking interval (keep-alive) can be set from the CX-Pro-
grammer in the TCP/IP keep-alive field of the Setup Tab in the Unit Setup.
The default setting is 120 minutes, as defined in RFC, but setting the timer
to several minutes is recommended when using FINS/TCP or other con-
trol applications.
Procedure for Using
FINS/TCP
Note Routing tables are required in the following situations:
• When communicating with a PLC or computer on another network (e.g.,
remote programming or monitoring using FINS messages or a CX-Pro-
grammer).
• When multiple Communications Units are mounted to a single PLC (i.e.,
CPU Unit).
1. Make the basic settings.
Refer to Section 2 Startup Procedure in the Operation Manual, Construction of Net-
works.
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2. Make the settings in the Unit Setup.
With the CX-Programmer connected online, select the Ethernet Unit in the CX-Program-
mer's I/O Table Window. Right-click, and select Unit Setup. Then make the following set-
tings in the Unit Setup Window.
Setup Tab
• FINS/TCP port (Default: 9600)
• TCP/IP keep-alive (Default: 120 minutes)
FINS/TCP Tab
• FINS/TCP server/client
Note: Set the server when connecting to host applications.
• Remote IP addresses
Note: When connecting to host applications, set the IP address of the permitted client
(personal computer or workstation) only when IP address protection is in effect. Do not
set if protection is not required.
• Automatically allocated FINS node addresses
• Keep-alive setting
• IP addresses protection setting
Note: When connecting to host applications, select this setting only when IP address
protection is in effect.
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3. Make the routing table settings and transfer them to each PLC. (See note.)
Set the routing tables with CX-Net, and transfer them to each PLC.
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4. Create host applications using a programming language such as C language and the
personal computer’s (workstation’s) socket interface.