udpRcvFromVar

 Function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. - Receives the contents of a variable from another controller through UDP User Datagram Protocol.

Inputs

Input	Data Type	Range	Unit	Default	Description
En	BOOL	0, 1	N/A	No default	Execute the function.
sock	DINT	0, 65535	N/A	No default	Socket number, return value from udpCreate.
add[ ]	USINT	0, 32	N/A	No default	Array which contains information about the server. This includes the sender's IP address.
varName	STRING		N/A	No default	The name of a PxMM variable (or array or structure) that stores data from the sender. The variable should be the same type as what is being sent. See udpSendToVar for more information.

Outputs

Output	Data Type	Range	Unit	Description
OK	BOOL		N/A	Returns TRUE when the function successfully executes. See Pipe Network - General Rules.
Q	DINT		N/A	Number of bytes received.

Remarks

• Receives the contents a variable sent from another controller and saves it to a local variable.
• This allows for the exchange of data across controllers.

Figure 1: udpRcvFromVar

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• Limitations

  • Function block A function block groups an algorithm and a set of private data. It has inputs and outputs. instance variable types are not supported.
  • These types of variables cannot be sent or received:
    • Variables defined with a UDFB User Defined Function Block - Used as a sub-function block in another program of the application. It is described using FBD, LD, ST or IL language. Input / output parameters of a UDFB (as well as private variables) are declared in the variable editor as local variables of the UDFB..
    • The Input and Output variables defined for a sub-program.
  • udpSendToVar and udpRcvFromVar do not automatically swap bytes for big vs. little endian systems.
  • Send / receive functionality is:

    	PCMM / AKD PDMM	PCMM2G	Simulator
    PCMM / AKD PDMM
    PCMM2G
    Simulator

    Compatibility is based on the endianness of the controller's information.
    PCMM and AKD PDMM are big-endian.
    PCMM2G and Simulator are little-endian.

  • 3rd party stand-alone programs The act of performing a sequence of instructions or commands. on x86 platforms are responsible for endian conversions for UDP telegrams from a AKD PDMM / PCMM.

FBD Language Example

FFLD Language Example

IL Language Example

Not available.

ST Language Example

            udpRcvFromVar( Socket_Number, Add, MyUDPVar )