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MELSEC-F
COMMUNICATION PROCEDURE5

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(2) Open system (connection numbers 1, 2; BFM#32, 33 b15, b14)

(a) Select the connection open system for each connection for which "TCP" is

selected in "(1) Protocol". If "UDP" is selected, the specification of this item is

not required.

(3) Fixed buffer (connection numbers 1, 2; BFM#32, 33 b0)

(a) Here it is selected whether the fixed buffer corresponding to each applicable

connection number will be used for sending or receiving when

communicating using the fixed buffers.

(b) When both sending and receiving are performed with an external device

using fixed buffer communication, one buffer for sending and one for

receiving are required. Thus, two connections should be set.

Name of setting Description of setting
Active Perform active open processing to an external device that waits for a passive open
(Fullpassive/Unpassive) on the TCP connection.
Unpassive
Perform passive open processing on the TCP connection addressing all the devices connected
to a network.
(The local station is placed in the wait status to wait for an Active open request to be sent.)
Fullpassive
Perform passive open processing on the TCP connection, only addressing specific devices.
(The local station is placed in the wait status to wait for an Active open request to be sent.)
The local station waits for an Active open request from the opposite station set in "(8)
Destination IP address".
Name of setting Description of setting
Send For sending.
Receive For receiving.

PLC main unit PLC main unit

Initial completion
Active open
Fullpassive/
Unpassove
open
Initial completion
Open completion
Active open

Ethernet module

Ethernet module

Initial request
Initial completion
Open request
Open completion
Initial request
Initial completion
Open completion
Open
Wait for open
request
FROM instruction
TO instruction
FROM instructionFROM instruction
TO instruction
FROM instruction