Pairing Open; Applications - Mitsubishi Melsec-L Series User Manual

(2) No procedure
In the application data for communications in the "No Procedure" control method, the following data code is
expressed in a binary code. Communications are performed using a binary code regardless of the
communication data code setting.
In communications in the "No Procedure" control method, a subheader or data length setting is not added unlike the
"Procedure Exist" control method; therefore, all data are handled as a valid text. In addition, the E71 turns on Fixed buffer
reception status signal after storing the size of the received message (packet) in the data length storage area. It is
recommended to set a checking method. For example, include data length and a data type code in the application data of a
message so that the number of bytes and data type of the application data can be identified on the receiving side.
10.7

Pairing Open

Pairing open is an opening method that connects the own station with the connected device using only one port by
pairing the receive and send connections for communications using a fixed buffer.
10.7.1

Applications

Enabling the pairing open allows data communications to be performed with two connections by performing the open
process for one port. MC protocol communications and communications using a random access buffer can be also
performed using paring-opened connections.
Connection No.1 Fixed buffer (to receive data)
Connection No.2 Fixed buffer (to send data)
● Connected devices where communications can be performed using the pairing open method are those in Ethernet where
an E71 is connected and those connected using the router relay function.
● The open/close processes in the receive connection where the pairing open has been enabled automatically perform the
open/close processes in the next connection (send connection).
Text (command)
Maximum of 2046 bytes
E71
CHAPTER 10 COMMUNICATIONS USING A FIXED BUFFER
(TCP/IP or UDP/IP communications)
Send data
Port
Receive data
Connected device
105
10