Libraries
9.4 Open user communication library
S7-200 SMART
516
System Manual, V2.3, 07/2017, A5E03822230-AF
Example
This is an example usage of the TCP_RECV instruction:
9.4.2.6
UDP_SEND instruction
The UDP_SEND instruction transmits the requested number of bytes (DataLen) from the
requested buffer location (DataPtr) to the device specified by the IP address (IPaddr1 –
IPaddr4) and port (RemPort). This instruction is used only for UDP protocol and connections
created with UDP_CONNECT.
LAD/FBD
STL
Description
UDP_SEND Req, ConnID,
DataLen, DataPtr, IPaddr1,
IPaddr2, IPaddr3, IPaddr4,
RemPort, Done, Busy, Er-
ror, Status
The UDP_SEND instruction transmits the requested number of
bytes from the requested buffer location to the device specified by
the IP address and port.
The UDP_SEND instruction initiates sending the specified number of bytes when the
following occur:
●
The program calls the instruction with the Req input set to TRUE.
●
The connection is not currently busy with another send operation.
The Req input is level-triggered. It is recommended that you put a positive edge trigger on
the Req input so that the instruction does not initiate unintended send operations. The
program ignores the Req input while the UDP_SEND is busy. The Done, Busy, and Error
outputs and the Status output byte show the status of the UDP_SEND for each call.