Thank you for reaching out. The ImageTrigger Box is for accessing the camera, my question is what do you exactly mean by a trigger signal. Do you want to trigger the Camera again if you detect the circle, or do you want to acces the GPIO pins from the frame grabber? If it is the latter, I have attached a small VA example on how to access these.
Please let me know what do you need in detail.
I meant the GPO trigger. The example seems helpful, thank you!