TrendStorageReaderValueConverter (FB) ¶ FUNCTION_BLOCK TrendStorageReaderValueConverter This helper function block is used in conjunction with the TrendStorageReader and converts the values of the trend storage into a suitable format, e.g. into a string. Methods: ConvertToLREAL ConvertToREAL ConvertToString SetVariableConfiguration Structure: ConvertToLREAL (Method) ConvertToREAL (Method) ConvertToString (Method) SetVariableConfiguration (Method)

TrendStorageReaderValueConverter.ConvertToLREAL (METH) ¶ METHOD ConvertToLREAL : LREAL Converts a value read from the trend storage into a LREAL value. InOut: Scope Name Type Comment Return ConvertToLREAL LREAL Input iWhichVariable INT A 0-based index of the variable within all variables, i.e. must be less the parameter iCountVariables of method SetVariableConfiguration liValue LINT The value, that was read from TblTrendData xValueNULL BOOL Indicates, whether NULL is stored in the trend storage Output eError ETrendStorageReaderErrors Returns a ETrendStorageReaderErrors value indicating, where the processing was completed successfully or not. ETrendStorageReaderErrors.NoError: Completed successfully ETrendStorageReaderErrors.InvalidCall: ConvertToLREAL was called without calling method SetVariableConfiguration before ETrendStorageReaderErrors.WrongParameter: The value of the parameter iWhichVariable is invalid

TrendStorageReaderValueConverter.ConvertToREAL (METH) ¶ METHOD ConvertToREAL : REAL Converts a value read from the trend storage into a REAL value. InOut: Scope Name Type Comment Return ConvertToREAL REAL Input iWhichVariable INT A 0-based index of the variable within all variables, i.e. must be less the parameter iCountVariables of method SetVariableConfiguration liValue LINT The value, that was read from TblTrendData xValueNULL BOOL Indicates, whether NULL is stored in the trend storage Output eError ETrendStorageReaderErrors Returns a ETrendStorageReaderErrors value indicating, where the processing was completed successfully or not. ETrendStorageReaderErrors.NoError: Completed successfully ETrendStorageReaderErrors.InvalidCall: ConvertToREAL was called without calling method SetVariableConfiguration before ETrendStorageReaderErrors.WrongParameter: The value of the parameter iWhichVariable is invalid

ITrendStorageAccessReadOperator.YAxisDescriptionRead (METH) ¶ METHOD YAxisDescriptionRead Notification, that the description of a y axis of a variable was read from table TblDiagramConfiguration. InOut: Scope Name Type Comment Input iWhichVariable INT The 0 based index of the variable within all variables wsYAxisDescription WSTRING The text ID

TrendFbDatabaseAccessErrorHandler.prvGetActionName (METH) ¶ METHOD prvGetActionName : STRING Returns the name corresponding to an action identifier InOut: Scope Name Type Comment Return prvGetActionName STRING Input iAction INT An int describing the action

TrendFbDatabaseAccessErrorHandler.prvGetErrorDescription (METH) ¶ METHOD prvGetErrorDescription : STRING Returns a brief description of an error code InOut: Scope Name Type Comment Return prvGetErrorDescription STRING Input eError STO.ERROR The error code coming from sqlite

TrendFbDatabaseAccessErrorHandler.prvGetFunctionName (METH) ¶ METHOD prvGetFunctionName : STRING Returns the name corresponding to a method or function identifier InOut: Scope Name Type Comment Return prvGetFunctionName STRING Input iFunction INT An int describing the method or function

TrendFbTrendStorageWriterReader.BuildBuffer (METH) ¶ METHOD BuildBuffer This method builds the buffer based on the passed TrendStructTraceTemporaryStorageInfo variables InOut: Scope Name Type Comment Input paStorageInfo POINTER TO ARRAY [0..0] OF TrendStructTraceTemporaryStorageInfo Contains the description of every variable and the buffer with the samples

TrendFbTrendStorageWriterReader.CleanBuffer (METH) ¶ METHOD CleanBuffer

TrendFbTrendStorageWriterReader.InitializeBufferReader (METH) ¶ METHOD InitializeBufferReader This method will be called to initialize the according buffer client object. Please remark that it might be called several times (maybe initially and after each call to ITrendStorageWriterSupportsBufferClients.AttachBufferClient ) but with similar arguments so it is ok to ignore possible afterwards calls. Additionally it should be synchronized internally as calls are possible from both the task of the trendrecording as well as from the task calling ITrendStorageWriterSupportsBufferClients.AttachBufferClient InOut: Scope Name Type Comment Input xHasToSwap BOOL Indicates, whether the data has to be swapped or not pAbsoluteTimestampProvider POINTER TO TrendFbAbsoluteTimestampProvider Instance, that converts relative timestamps to absolute timestamps paitfTraceMgrVariables POINTER TO ARRAY [0..0] OF ITraceMgrVariable The variables of the trend recording iCountVariables INT The effective size of the array above udiCountSamples UDINT The number of samples, that the trend element displays