Mitsubishi Electric MELSEC iQ-R Series - Page 1096

1094
8 BUILT-IN ETHERNET FUNCTION INSTRUCTIONS
8.2 Socket Communications Instructions
■Control 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).
• The following figure shows the timing of receive processing using the S.SOCRCVS instruction.
Precautions
When reading receive data from the same connection, do not use this command together with the SP.SOCRCV instruction.
Operand: (d)
Device Item Description Setting range Set by
+0 Receive data length The length of the data read from the socket communications receive data area is
stored.
(Number of bytes)
0 to 10238 System
+1 to + Receive data The data read from the socket communications receive data area is stored
sequentially in ascending order of addresses.
*1
 System
··
(d1)+0
(d1)+1
(d1)+2
(d1)+n
CPU module
Receive data length
S.SOCRCVS
(reading
receive data)
Socket communications
receive data storage area
Connection number
specified by (s)
Receive data
Receive data
Receive data
External device
Receiving
data
END0
OFF
OFF
OFF
OFF
OFF
ON
END0 END0 END0
ON
ON
Sequence scan
Open completion signal
(SD1504.n)
Socket communications
reception status signal
(SD1506.n)
S.SOCRCVS instruction
Reading data
Receiving data
Open
processing
Data receive
processing
Data read
processing
ACK
(TCP only)
Execution of the instruction