Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1096

■Control data
Operand: (d)
Device Item
+0 Receive data length
+1 to + Receive data
*1 The received data is stored in units of bytes sequentially from lower bytes. When an odd number of bytes of data is received, the last
receive data is stored in the lower byte of the last data storage area.
• The default receive data size is 2046 bytes. To receive 2047 bytes of data or more, change the receive data
size using the SP.SOCRMODE instruction.
• When an odd number of bytes of data is received, invalid data is stored in the higher byte of the device
where the last receive data is stored.
Processing details
• The S.SOCRCVS instruction reads the receive data of the connection specified by (s) from the socket communications
receive data area (where the data received from an external device in each connection is stored).
Receive data length
(d1)+0
Receive data
(d1)+1
Receive data
(d1)+2
· ·
Receive data
(d1)+n
• The following figure shows the timing of receive processing using the S.SOCRCVS instruction.
Open completion signal
(SD1504.n)
Sequence scan
Socket communications
reception status signal
(SD1506.n)
S.SOCRCVS instruction
Precautions
When reading receive data from the same connection, do not use this command together with the SP.SOCRCV instruction.
8 BUILT-IN ETHERNET FUNCTION INSTRUCTIONS
1094
8.2 Socket Communications Instructions
Description
The length of the data read from the socket communications receive data area is
stored.
(Number of bytes)
The data read from the socket communications receive data area is stored
sequentially in ascending order of addresses.
CPU module
Socket communications
receive data storage area
Connection number
specified by (s)
S.SOCRCVS
(reading
receive data)
Open Data receive
processing processing
ON
OFF
0 END 0
OFF
OFF
Receiving data
*1
Receiving
data
Data read
processing
END 0 END
ON
Execution of the instruction
ON
Reading data
ACK
(TCP only)
Setting range Set by
0 to 10238 System

System
External device
0 END
OFF
OFF