Omron V750 series, Network Connection Manual

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9. Program
9.1.2. TCP Socket Communications with Socket Service Instructions
This section explains the TCP socket communications performed by using the TCP socket
service function blocks (hereinafter referred to as socket service instructions) and outlines
the general operation of the send/receive message.
Additional Information
For details, refer to
Communications Instructions
in
Section 2 Instruction Descriptions
of the
NJ-series Instructions Reference Manual
(Cat. No. W502).
● TCP Socket Services with Socket Service Instructions
This program uses the following 5 types of standard instructions to perform socket
communications.
Name Function blocks Description
Connect TCP
Socket SktTCPConnect Connects the TCP port of the destination device.
TCP Socket
Send SktTCPSend Sends data from a specified TCP socket.
TCP Socket
Receive SktTCPRcv Reads the data from the receive buffer for a
specified TCP socket.
Close TCP
Socket SktClose Closes a specified TCP socket.
Read TCP
Socket Status SktGetTCPStatus Reads the status of a specified TCP socket.
By using this instruction, this program checks if the
receive processing is completed at the receive
processing and checks the closing status at the
close processing.
*The socket obtained by the Connect TCP socket instruction (SktTCPConnect) is used as
an input parameter for another socket service instruction. The data type of Socket is
structure _sSOCKET. The specifications are as follows.
Variable Meaning Description Data type Valid range Default
Socket Socket Socket _sSOCKET - -
Handle Handle Handle for data
communications UDINT Depends on
data type
-
SrcAdr Local
address Local address *1 _sSOCKET_ADD
RESS - -
PortNo Port
number
Port number UINT 1 to 65535
IpAdr IP address IP address or host name
*2 STRING Depends on
data type
DstAdr Destination
address Destination address *1 _sSOCKET_ADD
RESS - -
PortNo Port
number
Port number UINT 1 to 65535
IpAdr IP address IP address or host name
*2 STRING Depends on
data type
*1: The address indicates an IP address and a port number.
*2: A DNS or Hosts setting is required to use a host name.
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