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MELSEC-F
COMMUNICATION PROCEDURE
5
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5.7 Pairing Open
The following explains communication using the paring open method via the Ethernet
module.
5.7.1 Pairing open
Pairing open is an opening method for establishing a connection in which the local
station and the external device use a single port for each, by pairing the receiving and
sending connections through fixed buffer communication (both the procedure exists
and no procedure are allowed) of the Ethernet module.
By designating the pairing open method, data communication can be performed with
two connections by performing open processing for only one port.
Communications using MC protocol can also be performed using these pairing
opened connections. (The single connection is also possible for the communication
using MC protocol)
The procedure for performing the open/close processing for pairing open is explained
below.
[Example]
POINT
(1) When setting the pairing open method, the fixed buffer of the applicable
connection number (for receiving only) and the fixed buffer of the next
consecutive connection number (for sending only) are paired in the order of
receiving, then sending.
For the applicable connection (for receiving only), choose connection No. 1 to
7.
(2) The range of external devices that can be communicated by the pairing open
method are limited to devices on the Ethernet to which the Ethernet module is
connected and devices connected with the router relay function (see Section
5.3, "Router Relay Parameter").
(3) By the open/close processing of the applicable connection (for receiving only)
for which the pairing open method has been set, the open/close processing of
the next connection (for sending only) will automatically be performed.
Ethernet module
Connection No. 1 fixed buffer (for receiving)
Connection No. 2 fixed buffer (for sending)
(TCP/IP or UDP/IP communication)
Send data
Port
Receive data
External device