UA_Browse

This function block allows browsing through the namespace of a server. Starting from a start node, its references are read and returned accordingly.

Inputs

VAR_INPUT
    Execute             : BOOL;
    ConnectionHdl       : DWORD;
    BrowseDescription   : ST_UABrowseDescription;
    ContinuationPointIn : DWORD;
    Timeout             : TIME; 
END_VAR

Name	Type	Description
Execute	BOOL	The command is triggered by a rising edge at this input.
ConnectionHdl	DWORD	Connection handle previously output by the function block UA_Connect.
BrowseDescription	ST_UABrowseDescription	The address information for the node to be read is specified here.
ContinuationPointIn	DWORD	If a previous call of the function block returned a value as ContinuationPointOut, this value can be created here to get further data from the server.
Timeout	TIME	Time until the function is aborted.

Inputs/outputs

VAR_IN_OUT
    ReferenceDescriptions : POINTER TO ST_UAReferenceDescriptions;
END_VAR

Name	Type	Description
ReferenceDescriptions	POINTER TO ST_UAReferenceDescriptions	Contains the list of ReferenceDescriptions returned by the server, i.e. the result of the UA_Browse call. The contained ReferenceDescriptions can then be used for further UA_Browse calls in the BrowseDescription, e.g. to navigate deeper into the namespace.

Outputs

VAR_OUTPUT
    Done                 : BOOL;
    Busy                 : BOOL;
    Error                : BOOL;
    ErrorID              : DWORD;
    ContinuationPointOut : DWORD;
    cbBrowseResultCnt    : UDINT;
END_VAR

Name	Type	Description
Done	BOOL	Switches to TRUE if the function block was executed successfully.
Busy	BOOL	TRUE until the function block has executed a command, at the most for the duration of the "Timeout" at the input. The inputs accept no new command as long as Busy = TRUE. It is not the connection time that is monitored but the reception time.
Error	BOOL	Switches to TRUE if an error occurs while executing a command. The command-specific error code is included in ErrorID.
ErrorID	DWORD	Contains the command-specific error code of the most recently executed command.
ContinuationPointOut	DWORD	If the server returns data batch-wise (ContinuationPointOut != 0), the value of ContinuationPointOut can be used as ContinuationPointIn at the next call of the function block to get the further data.
cbBrowseResultCnt	UDINT	Number of ReferenceDescriptions.

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT 3.1	Win32, Win64, CE-X86, CE-Arm®	Tc3_PLCopen_OpcUa