F_VN_ReadQRCodeExp
Detect and interpret a QR code within the provided image. Can be canceled by Watchdog.
Syntax
Definition:
FUNCTION F_VN_ReadQRCodeExp : HRESULT
VAR_INPUT
ipSrcImage : ITcVnImage;
ipDecodedData : Reference To ITcVnContainer;
ipContours : Reference To ITcVnContainer;
nCodeNumber : DINT;
eSearchStrategy : UDINT;
hrPrev : HRESULT;
END_VAR
Inputs
|
Name |
Type |
Description |
|---|---|---|
|
ipSrcImage |
Source image (USINT elements, 1 channel or 3 channel (3 channel input is expected to be RGB and internally converted to Gray)) | |
|
ipDecodedData |
Reference To ITcVnContainer |
Returns the decoded code (ContainerType_Vector_String_SINT) |
|
ipContours |
Reference To ITcVnContainer |
Returns the code positions as contours (optional, set to 0 if not required; ContainerType_Vector_Vector_TcVnPoint2_DINT) |
|
nCodeNumber |
DINT |
Number of QR codes that should be detected within the provided image (currently only 1 supported). |
|
eSearchStrategy |
UDINT |
Used search strategy (ETcVn2dCodeSearchStrategy) |
|
hrPrev |
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) |
Return valueFurther information
Notice | |
Floating point exceptions This function can unnecessarily cause errors if the option Floating point exceptions of the executing PLC task is active. Therefore, deactivate this option. |
The function F_VN_ReadQRCodeExp corresponds to the function F_VN_ReadQRCode, extended by the following parameters.
ipContour
The parameter ipContour returns the code position that is found as a contour.
nCodeNumber
The parameter nCodeNumber defines how many codes to search for.
 | Searching for more than one QR code not currently supported Searching for several QR codes in one image is currently not supported. The parameter nCodeNumber therefore has to be set to 1. |
eSearchStrategy
The parameter eSearchStrategy defines the search strategies for the code search. The standard option TCVN_CSS_DEFAULT leads to the search strategies TCVN_CSS_FIRST_NOT_INVERTED and TCVN_CSS_FIRST_NOT_FLIPPED. For a description of the search strategies see Code Reading search strategies.
Samples
Related functions
Required License
TC3 Vision Code Reading
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 |