Mitsubishi Melsec-L Series User Manual page 91

● When changing connected devices, do not use the pairing open or alive check function.
● When "No Procedure" is selected for a connection, the connection is dedicated to "No Procedure" communications using
a fixed buffer after the open process is completed. When "Procedure Exist" is selected for a connection, the following
data communications can be performed after the open process is completed.
• MC protocol communications
• Communications using a fixed buffer using the "Procedure Exist" control method
• Communications using a random access buffer
(3) Processes during data sending/receiving
(a) When data is sent
When a CPU module executes the BUFSND instruction, the E71 sends data of the applicable fixed buffer
number n to the connected device that is specified in Communication address setting area (addresses: 28
5F ) corresponding to the fixed buffer number n.
H
(b) When data is received
An E71 processes the data that is received from the connected device set in the communication address
setting area corresponding to the fixed buffer number n.
In addition, when an E71 stores the received data in the corresponding fixed buffer in the receive process, it
updates the IP address and destination port number of the connected device in Connection information area
(addresses: 78 to C7
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If data is received from a connected device not set in the connection information area of the buffer memory, an
E71 ignores the received data.
*1 With the TCP/IP Unpassive open, data is sent to or received from a connected device stored in the connection
information area of the buffer memory.
When received data is stored in the corresponding fixed buffer in the receive process of broadcast communications, an E71
updates the destination IP address and port number in Connection information area (address: 78
586F ) corresponding to the fixed buffer number n.
H
and 5820 to 586F ) corresponding to the fixed buffer number n.
H H H
CHAPTER 10 COMMUNICATIONS USING A FIXED BUFFER
*1
to
H
to C7 and 5820 to
H H H
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10