FB_XmlSrvReadByName
The function block FB_XmlSrvReadByName can be used to initialize a PLC variable with data from an XML file. The input variable sXPath must point to a valid node in the XML file specified via sFilePath. The symbol to be initialized is identified unambiguously by the symbol name.
VAR_INPUT
VAR_INPUT
sNetId : T_AmsNetId;
ePath : E_OpenPath := PATH_GENERIC;
nMode : WORD := XMLSRV_SKIPMISSING;
sSymName : T_MaxString;
sFilePath : T_MaxString;
sXPath : T_MaxString;
bExecute : BOOL;
tTimeout : TIME := T#60s;
END_VAR
sNetId: String containing the network address of the TwinCAT XML Data Server. For the local computer (default) an empty string may be specified.
ePath: This input can be used to select a TwinCAT system path on the target device for opening the file.
nMode: This input can be used to influence how the XML file is analyzed. For the XmlSrvReadByName command, only XMLSRV_SKIPMISSING mode is currently supported.
sSymName: Name of the PLC symbol to which the data from the XML file are to be written.
sFilePath: Contains the path and file name for the file to be opened. Note: The path can only point to the local computer’s file system! This means that network paths cannot be used here!
sXPath: Contains the address of the tag in the XML document from which the data are to be written. The address must be a valid XPath instruction. The name of the tag must be different from the name of the symbol.
bExecute: The block is activated by a rising edge at this input.
tTimeout: Maximum time allowed for the execution of the function block.
VAR_OUTPUT
VAR_OUTPUT
bBusy : BOOL;
bError : BOOL;
nErrId : UDINT;
END_VAR
bBusy: This output is set when the function block is activated. It remains set until feedback is received.
bError: This output is set up after the bBusy output has been reset if there has been an error in transmission of the command.
nErrId : If the bError output is set, this parameter returns the TwinCAT XML Data Server error number.
Requirements
Development environment | Target system type | PLC libraries to be linked |
---|---|---|
TwinCAT v2.10.0 | PC or CX (x86, ARM) | TcXmlDataSrv.Lib ( Standard.Lib; TcBase.Lib; TcSystem.Lib are included automatically ) |