Mitsubishi Electric MELSEC iQ-R Series User Manual page 546

Communication flow
This section describes the flow from the establishment of connection to end of communication.
After performing
Passive open, the server
will wait for an open request
from the client.
Wait at least 500ms or more before executing the open processing again after the close request is sent from
the external device to the CC-Link IE TSN Plus module.
APPX
544
Appendix 8 TCP/IP Communications, UDP/IP Communications
Server
CC-Link IE TSN Plus module
Passive open
Connection established
Receive processing
Data sending
Close request
Closed
Client
External device
Open request
Active open
Response
Connection established
Data sending
Data sending
Response
Data sending
Response
Receive processing
Close request
Close processing
Response
Close request
Response
Closed
When the client sends
an Active open request
and the server accepts it,
a connection is established
between the client and the
server.
The client requests data
sending and sends data.
The client receives the response
to the data.
The client receives data and sends
back the response to the data.
The packet to stop communications is
exchanged then the connection is
disconnected.