📦 Sample — TR-Vision-BasicExercises

• This is an unofficial, unsupported quickstart sample project. It is an excerpt of the TF7xxx TwinCAT Vision training course offered by Beckhoff Automation BV. The sample code is provided as-is under the Zero-Clause BSD license.
• This quick start does not replace any official documentation or training. Please refer to the local Beckhoff subsidiary for the complete training session.
• Minimum TwinCAT version: 3.1.4026.15
• Requires TF7xxx | TC3 Vision (>= 4.0.7.4) to be installed
• Requires TwinCAT HMI (>= 1.14.3) for exercise 03_Hmi
• The project uses FB_VN_FileSourceControl by default (file source). To use a GigE Vision camera, uncomment the FB_VN_GevCameraControl or FB_VN_SimpleCameraControl line in MAIN_VISION and comment out the file source line.
• Sample images are provided in Documentation/00_Images/

The repository contains three progressive exercises, each building on the previous one. Every exercise ships a Project folder (editable source), a Solution folder (packaged .tszip), and a Templates folder (starting point).

Sets up the basic TwinCAT Vision project structure: camera control state machine, image acquisition, and image pipeline (original, work, result, displayable copies). The vision algorithm section is left empty for the trainee to fill in.

Extends the base with a complete vision pipeline:

1. Color range check (F_VN_CheckColorRange) to threshold by RGB bounds
2. Contour detection (F_VN_FindContours) on the thresholded image
3. Contour iteration and filtering by area (> 100 000 px)
4. For each qualifying contour: draw outline, compute center of mass, find enclosing rectangle, and label with text

Same PLC logic as 02_Analysis, plus a TcHmi_Vision HMI project (TcHmi_Vision.hmiproj) that demonstrates the TwinCAT Vision HMI control for live image display in a web-based dashboard.

The central program in every exercise. It drives the camera through a state machine based on ETcVnCameraState:

Key variables:

Minimal vision program that acquires images from a file source and applies a color range check (from exercise 02_Analysis):

PROGRAM MAIN_VISION
VAR
    eControlState   : ETcVnCameraState;
    fbControl       : FB_VN_FileSourceControl;
    hr              : HRESULT;
    ipImage         : ITcVnImage;
    ipImageDisp     : ITcVnDisplayableImage;
    ipImageWork     : ITcVnImage;
    ipImageWorkDisp : ITcVnDisplayableImage;
    aLowerBounds    : TcVnVector4_LREAL := [25, 25, 80, 0];
    aUpperBounds    : TcVnVector4_LREAL := [100, 100, 160];
END_VAR

eControlState := fbControl.GetState();

CASE eControlState OF
    TCVN_CS_INITIAL, TCVN_CS_OPENING, TCVN_CS_OPENED, TCVN_CS_STARTACQUISITION:
        hr := fbControl.StartAcquisition();

    TCVN_CS_ACQUIRING:
        hr := fbControl.GetCurrentImage(ipImage);
        IF SUCCEEDED(hr) AND ipImage <> 0 THEN
            hr := F_VN_CopyImage(ipImage, ipImageWork, hr);
            hr := F_VN_TransformIntoDisplayableImage(ipImage, ipImageDisp, S_OK);
            // Apply color range check
            hr := F_VN_CheckColorRange(ipImageWork, ipImageWork, aLowerBounds, aUpperBounds, hr);
            hr := F_VN_CopyIntoDisplayableImage(ipImageWork, ipImageWorkDisp, hr);
        END_IF

    TCVN_CS_ERROR:
        fbControl.Reset();
END_CASE

To switch from file source to a live GigE Vision camera, replace FB_VN_FileSourceControl with FB_VN_GevCameraControl and configure the camera connection in the TwinCAT System Manager.

• The VisionTask runs at priority 1 (highest) to ensure deterministic image processing. The PlcTask runs at priority 20 for general PLC logic.
• After calling F_VN_TransformIntoDisplayableImage, the source ITcVnImage interface is no longer valid. Use F_VN_CopyIntoDisplayableImage when you still need the source image for further processing.
• The watchdog variables (hrWD, tWDStop, tRest, etc.) are declared but not actively used in the sample code — they are prepared for trainees to implement watchdog monitoring.
• Contour filtering in exercise 02_Analysis uses a threshold of 100 000 pixels. Adjust this value to match your image resolution and object sizes.
• The F_VN_ConvertColorSpace call is commented out. Uncomment it (and comment out the F_VN_CopyImage line above it) when working with Bayer-encoded camera images instead of RGB file sources.

Required libraries

Minimum TwinCAT version: 3.1.4026.15

License: BSD Zero Clause