Checking the Applet's functionality when a camera is disabled

  • Hi All,

    I am working with three GV-5260 CP cameras connected to VQ4-GE frame grabber running in triggered mode and sequencing the images captured from these cameras to the DMA of the PC.

    Now I need to run the applet by disabling one of the cameras and give a dummy image source instead. But the applet is working only if all the three cameras are powered up and connected , so in case of a camera failure the applet is not functioning. I have attached my applet for your reference, please suggest me a solution!



  • Hello Jayasuriya

    first of all I like to inform you about this post: How to acquire images by turns using multi cameras? Maybe you find some answers there. Besides other information you can read the following:

    ... as you are using a GigEVision camera the camera explicitly needs to be started. microDisplay will do that for you when you click the Play button. However it will start camera 0 with DMA 0. Camera 1 with DMA 1. Etc. As you only have a single DMA camera 1 (you call it camera 2) will not be started by microDisplay.

    Solution: Open the GenICam explorer and connect with the second camera. Search for parameter StartAcquisition and click Execute. This shall start the second camera and you can acquire the images with microDisplay.

    You won't have that type of problem when you integrate the frame grabber with the API using the SDK as you need the code to start the cameras anyway. If you are using a 3rd party interface like Halcon you need to check it.

    In your case your design will work if you can change the operator SourceSelector only between two frames. So you need to stop all cameras, let the pipeline get empty, change the SourceSelector source and restart let's say two out of three cameras.

    If you have a disabled camera asynchronous to your trigger. For example because of a failure you won't be able to switch to your fallback solution. Especially if it is in the middle of a frame transfer. The operators can only switch at the end of a frame.

    Maybe you can further explain the expected camera issues so that I can think about a workaround.


    Johannes Trein
    Group Leader R&D
    frame grabber

    Basler AG

  • Hi Johannes,

    Sorry for the late reply. Actually what was my concern is that ' I need to set the dummy source before starting the image acquisition' , then the applet should function without waiting for that particular camera which has been set to give dummy source to be started in genicam explorer.

    Now I have achieved this by simply putting the image buffer after the source selector operator.





    So this doesn't blocks the image flow since the buffer is filled by dummy source instead of waiting for images from camera source:).