FB_VN_ReadMlModel

Syntax

Definition:

FUNCTION_BLOCK FB_VN_ReadMlModel
VAR_INPUT
    sFilePath     : STRING;
    ipDestMlModel : Reference To  ITcVnMlModel;
    bRead         : BOOL;
    nTimeout      : TIME;
END_VAR
VAR_OUTPUT
    bBusy         : BOOL;
    bError        : BOOL;
    nErrorId      : UDINT;
END_VAR

Inputs

Name	Type	Default	Description
sFilePath	STRING		Full path of the file or relative path to the default directory on the target pc
ipDestMlModel	Reference To ITcVnMlModel		Returns the loaded machine learning model
bRead	BOOL		Reading the file is triggered by a rising edge at this input.
nTimeout	TIME	VISION_ADS_TIMEOUT	Indicates the time before the function is cancelled.

Outputs

Name	Type	Description
bBusy	BOOL	This output remains TRUE until the function block has executed a command, but at the longest for the duration supplied to the 'nTimeout' input. While bBusy = TRUE, no new command will be accepted at the inputs.
bError	BOOL	This output is switched to TRUE as soon as an error occurs during the execution of a command. The command-specific error code is contained in ‘nErrorId’. If the function block has a timeout error, 'bError' is TRUE and 'nErrorId' is 1861 (hexadecimal 0x745). Is reset to FALSE by the execution of a command at the inputs.
nErrorId	UDINT	Contains the ADS error code or the command-specific error code of the last executed command. Is reset to 0 by the execution of a command at the inputs.

Further information

The function block FB_VN_ReadMlModel loads an ML model from a file asynchronously into the PLC.

	Loading of modified ML models When loading the ML model, the vision service caches the data internally. Loading modified ML models is therefore not possible in the standard system. To do this, adjust the cache settings or see the example Serial loading of images into the PLC for an alternative.

Parameter

Some parameters are described centrally in the section File Access Parameters.

Loaded ML model (return value)

The loaded ITcVnMlModel is reachable via the interface pointer ipDestMlModel following successful reading.

A special case is the use as ITcVnColorModel, because after loading the model a conversion with the following row is still necessary. Alternatively, the ITcVnMlModel can also be used directly with the corresponding functions.

hr := ipReadMlModel.TcQueryInterface(IID_ITcVnColorModel, ADR(ipColorModel));

Application

Loading an ML model from the path C:\TcVision\MlModel.vmlm looks like this, for example:

fbReadMlModel(
    sFilePath       := 'C:\TcVision\MlModel.vmlm', 
    ipDestMlModel   := ipReadMlModel,
    bRead           := TRUE,
    nTimeout        := T#500MS);

IF NOT fbReadMlModel.bBusy AND NOT fbReadMlModel.bError THEN
    // Ml-Model is accessible in ipReadMlModel
END_IF

Related function block: FB_VN_WriteMlModel.

Required License

TC3 Vision Base

System Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT V3.1.4024.54 or later	PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU	Tc3_Vision