UA_ReadList

This function block reads values from several given node and connection handles.

Inputs

VAR_INPUT
    Execute          : BOOL;
    ConnectionHdl    : DWORD;
    NodeHdlCount     : UINT;
    NodeHdls         : ARRAY[1..nMaxNodeIDsInList] OF DWORD;
    stNodeAddInfo    : ARRAY[1..nMaxNodeIDsInList] OF ST_UANodeAdditionalInfo;
    pVariable        : PVOID;
    cbData           : ARRAY[1..nMaxNodeIDsInList] UDINT;
    cbDataTotal      : UDINT;
    Timeout          : TIME := DEFAULT_ADS_TIMEOUT;    
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.
NodeHdlCount	UINT	Number of node handles stored in the input variable NodeHdls.
NodeHdls	ARRAY	Array of node handles previously received by the function block UA_NodeGetHandle or UA_NodeGetHandleList.
stNodeAddInfo	ARRAY	Defines additional information, such as which attribute is read from the UA namespace (default: 'Value' attribute) or which IndexRange is to be used. Specified by STRUCT ST_UANodeAdditionalInfo.
pVariable	PVOID	Pointer to data memory where the read data is to be stored.
cbData	ARRAY	Determines the size of the data to be read.
cbDataTotal	UDINT	Total size of the data to be received.
Timeout	TIME	Time until the function is aborted. DEFAULT_ADS_TIMEOUT is a global constant, set to 5 seconds.

Outputs

VAR_OUTPUT
    Done      : BOOL;
    Busy      : BOOL;
    Error     : BOOL;
    ErrorID   : UDINT;
    cbData_R  : 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 in nErrID.
ErrorID	UDINT	Contains the command-specific ADS error code of the most recently executed command.
cbData_R	UDINT	Number of bytes read.

Requirements

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