Mitsubishi Electric MELSEC iQ-R Series User Manual page 188

■Checking the receive data length
There is no concept of delimiting the communication data during communication with TCP/IP. Thus, the continuously sent
data may be merged on the received side, or the data sent in a group may be split on the receive side. If necessary, the
receiving side must check the receive data length and perform the processing.
If the data length is determined when receiving with the CC-Link IE TSN Plus module side, using the fixed-length mode is
recommended.
When receiving on the external device side, check the receive data length and perform the processing as shown below.
Receive the rest of the message.
9 FUNCTIONS
186
9.4 Ethernet Connection
Receive processing on the external device side
Received message, receive processing
Is TCP connection open?
YES
Has data been received within
the time specified by the monitoring
timer value?
Check the received data size.
NO
Is receive data size insufficient?
YES
Processing for the received message
Was the entire received message
processed?
YES
End
NO
NO
YES
NO
TCP connection is closed.
Error handling