6-1
Section
Overview
91
4. When the receiving user program sends a request to receive 1,984 bytes of
data, Data A and Data B are linked to restore the original data, which is
passed to the user program.
Source data
1,984bytes
Sending User Program
1. Send request
Data A
Data B
1,472 bytes
512 bytes
Ethernet Unit
Receiving Node
Receiving User Program
4. First receive request
1,984 bytes
Data A
Data B
3.
2.
As shown above, the UDP protocol handles data communications as data-
grams, so that the send data is restored to the original data before being passed
to the user program. Consequently, if the data length in the receive request is set
to the length of the send data, the entire data can be received using a single re-
ceive data request. However, if the data length in the receive data request is set
smaller than the actual length of the data, all received data exceeding the set
data length will be discarded.
