Yes, that may well be the case. I just set it up again and played with it in light of this discussion. It takes about a 1-2 seconds to catch the dark cork in front of the white ceiling. If the cork rectangle has fully cleared the tripwire, the cork is safe from detection. And oddly enough, under some circumstances, the cork isn't even detected for a long time.I've found my single 2231 to have a higher missed detection rate than other models. Even the old chinese market cameras do better. Perhaps they overshot in trying to reduce false positives? I do not use human/vehicle detection.
I'm getting no response from the lines at all.
Do you have an SD card in the camera to confirm it is triggering?
Can you access the camera directly through IE explorer? If so, check the camera log for triggers. It should record in its internal log motion detects and triggers.
Open the camera Web GUI (which model is it anyway?)There are no logs. It only has an option in Reports for Heat and People Counting.