UA_GetNamespaceIndex

UA_GetNamespaceIndex 1:

This function block collects the namespace index for a namespace URI. The namespace index is required for identifying symbols, for example, if the function blocks UA_Read or UA_Write are used.

UA_GetNamespaceIndex 2: Inputs

VAR_INPUT
    Execute       : BOOL;
    ConnectionHdl : DWORD;
    NamespaceUri  : STRING(MAX_STRING_LENGTH);
    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.

NamespaceUri

STRING

Namespace URI to be resolved. For the TwinCAT OPC UA Server, this is "urn:BeckhoffAutomation:Ua:PLC1“" for the first PLC runtime.

Timeout

TIME

Time until the function is aborted. DEFAULT_ADS_TIMEOUT is a global constant, set to 5 seconds.

UA_GetNamespaceIndex 3: Outputs

VAR_OUTPUT
    NamespaceIndex : UINT;
    Done           : BOOL;
    Busy           : BOOL;
    Error          : BOOL;
    ErrorID        : DWORD;
END_VAR

Name

Type

Description

NamespaceIndex

UINT

Namespace Index of the given namespace URI. This can be used in other function blocks, e.g. UA_NodeGetHandle or UA_MethodGetHandle.

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.

Requirements

Development environment

Target platform

PLC libraries to include

TwinCAT 3.1

Win32, Win64, CE-X86, CE-Arm®

Tc3_PLCopen_OpcUa