Mitsubishi Electric Q03UDVCPU User Manual page 132

(3) Function
This instruction changes the TCP receive mode and receive data size of the connection specified in
mode is changed as specified in
(a) TCP standard receive mode
When data are received, they are stored in the Socket communication receive data area, and SD1286 turns on.
If data are received exceeding the specified receive data size, the excess data are read out the next time.
Ex The receive data size is set to 300 bytes, and 500-byte data are received. Ex.
Reading receive data
Socket communication
receive data area
SD1286
(b) TCP fixed-length receive mode
When data are received, they are stored in the Socket communication receive data area, and SD1286
(Receive state signal) turns on. However, if the size of the data does not reach the specified receive data size,
SD1286 does not turn on.
Data reception is repeated and once the data size reaches to the specified size, SD1286 turns on.
If data are received exceeding the specified receive data size, the excess data are read out the next time.
Ex. The receive data size is set to 300 bytes, and 200-byte data are consecutively received.
Reading receive data
Socket communication
receive data area
SD1286
130
+2. (This instruction is invalid for UDP connections.)
S2
Data stored
(300 bytes)
ON
OFF
Data reception
(500 bytes)
Data cannot be read out because
the receive data size is not reached.
Data stored
(200 bytes)
ON
OFF
Data reception
(200 bytes)
SP.SOCRCV or
S.SOCRCVS
instruction
Data stored
Data reading
(200 bytes)
SP.SOCRCV or
S.SOCRCVS
instruction
Data reading
Data stored
(300 bytes)
Data reception
(200 bytes)
. The
S1
SP.SOCRCV or
S.SOCRCVS
instruction
Data reading
The remaining 100
bytes will be stored
at the next data
reception (200 bytes).