Udp/Ip Communications - Mitsubishi Electric MELSEC iQ-R Series User Manual

UDP/IP communications

This section describes the UDP/IP communications. Since UDP/IP communications does not establish a connection during
communication and does not check that the communication destination has correctly received the data, the line load is lower.
Note that the data reliability is lower than TCP/IP communications.
Communication flow
UDP/IP communications does not require a process to establish a connection with the external device as is required with
TCP/IP communications.
The server requests
data reception and
reads the received data.
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.
Open procedure
The open/close processing procedure is as follows, according to the setting of "Opening Method" under "Own Node Settings"
in "Basic Settings". ( Page 81 Own Node Settings,  Page 113 Own Node Settings)
■When "Do Not Open by Program" is set
After the CC-Link IE TSN Plus module mounted station starts up, the UDP/IP communications setting connection
automatically opens, and data send/receive is enabled. Program for open/close processing is not required.
When the open/close processing is executed with a dedicated instruction from the CC-Link IE TSN Plus
module, even if "Do Not Open by Program" is set in "Opening Method" under "Own Node Settings" in "Basic
Settings", the open/close processing after a connection with the external device is established must be
executed by the program.
APPX
548
Appendix 8 TCP/IP Communications, UDP/IP Communications
Server
CC-Link IE TSN Plus module
Open
Receive processing (reading)
Data sending request
Close
Client
External device
Open
Data sending
Data sending request
Data sending
Receive processing (reading)
Close
The client opens
the port.
The client specifies
the destination and
sends data to it.
The client performs
the close processing.