Even a slight tilt of the test object can cause deviations in length measurements. Even a telecentric lens can not really minimise this problem, precise positioning of the object remains essential.

This occurs when the object moves while the sensor is exposed. This results in blurred images. Possible solutions include reducing the exposure time, using stronger lighting, increasing the aperture size, or raising the camera gain.

Perspective distortions can be caused by deviations in the X and Y position of the object. This can be remedied by improving mechanical positioning or using telecentric lenses.

Machine vibrations can cause images to appear blurred. The effects can be reduced using vibration dampers and hardware decoupling.

Dirt particles can contaminate lenses and damage electronic components. Using IP-certified housings or air curtains protects the components.

Disturbing light sources from outside (e.g., windows or ceiling lights) can overexpose the image or reduce contrast. Enclosing the system or using bandpass filters in combination with monochromatic LEDs eliminates this problem.

High temperatures can increase sensor noise and shorten the service life of electronics. Cooling housings and heat reflection filters are effective solutions to this problem.

EMC interference can result in incorrect trigger signals or damaged data. Important protective measures include improved shielding, correct grounding and the alternative use of fibre optic cables.

One of the most common and confusing problems in industrial image processing is a completely black image. This indicates that either no light is reaching the camera, or the signal is being lost en route to the PC. Systematic troubleshooting requires a thorough examination of both the hardware and the software.

1. Basic Optical and Lighting Check

Is the lighting on/off?

First, check whether the lighting is active at all. See if the light is on, or test it separately as described in the previous example to rule out a defect.

Is the lens aperture misaligned?

A common but simple cause that is often overlooked is an accidentally closed or misaligned aperture (iris). Visually inspect the lens and make sure the aperture is fully open.

2. Hardware and Cable Check

Hardware defects:

Both the camera and the lighting can be defective. If the lighting is working and the aperture is open, the camera itself may be faulty.

Broken cable:

Check all cable connections. A broken cable in the camera's power supply, the trigger cable, or the image transfer cable (e.g., Ethernet or USB) can lead to a complete failure of image capture.

3. Software and Trigger Check

Software / Hardware Trigger Configuration:

Make sure the trigger settings in the software are correct. An incorrectly configured trigger can cause the camera not to fire at the right time or to completely refuse to capture an image.

Is there a PLC Trigger In > Strobe Out signal?

Check the interaction between the PLC, camera, and strobe controller. Is the PLC even sending a trigger signal? And is this converted by the software into a 'Strobe Out' signal for the lighting?

Freerunning test:

Switch the camera to freerunning mode (without a PLC trigger). If an image is captured in this mode, the problem lies with the trigger communication.

4. Advanced Diagnosis

Testing with an oscilloscope:

An oscilloscope can be used to accurately check the trigger signal. Measure whether the PLC's trigger signal is correctly arriving at the camera's input and whether the camera is sending the corresponding 'Strobe Out' signal.

Testing with new software program without tools:

Sometimes, a fault can lie in a complex software program or a specific tool. Test the camera with a simple, standard image capture program from the manufacturer to see if image capture works fundamentally. If so, the problem lies in the complexity or configuration of the main application software.

When the lighting in an industrial camera system fails, it's often the most obvious cause of faulty images. The troubleshooting process should include both hardware and software checks.

1. Hardware Check

Is the light defective? The simplest and first check is to test the lighting independently of the camera system. Connect the light directly to a suitable power source to see if it still illuminates at all. If the light itself isn't working, it's defective and needs to be replaced.

Hardware defect / Broken cable: Check all cable connections between the controller (PLC), the strobe controller, and the lighting. A loose connector or a damaged cable can interrupt the signal transmission. Check the strobe controller: does it show status lights or error messages?

Strobe controller configuration: Many strobe controllers have their own settings or a user interface. Check that the controller is configured correctly, especially regarding current and pulse duration.

2. Software Check

PLC trigger: Ensure that the PLC is actually sending a trigger signal. Check the status of the "Trigger In" signal at the camera or the strobe controller.

Strobe Out signal software: Check whether the software sends the "Strobe Out" signal to the strobe controller when a trigger is received. This can be done by monitoring the signal in the software or by testing in a "freerunning" mode without a PLC connection.

Freerunning test: The best method for separating software and trigger issues from hardware is the "freerunning test." Configure the camera and strobe controller so that the light illuminates in a continuous mode or an internally triggered mode without requiring an external signal (e.g., from the PLC). If the light works in this mode, the problem lies in the control by the PLC or the communication between the devices.

By systematically working through these steps, the source of the fault can be quickly located and resolved to avoid unnecessary production downtime.