ZoneMinder Forums

Hi,

I have a DCS-920 at the far end of my wi-fi range and the signal is dropped several times a day (sometimes several times an HOUR depending on the weather) then resumed. This doesn't present a problem, however, every time this happens I get an alarm frame generated on the timeline that I would like to eradicate.

How can I do so?

Is there a way to specify that 2 or 3 changed frames will generate an alarm state as opposed to one? This way I could up the threshold and get rid of the numerous "false alarms" caused by the "blue screen" frame that appears when a signal loss occurs/resumes.

Thank you in advance for any pointers or tips.

In zone configuration try uping the Overload Frame Ignore Count value.

bb99 wrote:In zone configuration try uping the Overload Frame Ignore Count value.

What exactly does that do? The wiki omits that option completely (See here)

I tried setting this value from 0 to 4, but it does not appear to have made any difference?

"For sudden changes to the enviroment, no better tool then Overload Frame Ignore Count. Your fps determines these settings but at 10 fps with Overload Frame Ignore Count set to 4, it only ignors .4 seconds. In other words if a drastic change to the lighting (such as a car with headlights on in darkness) passes within the monitors view it will ignore the number of frames you specify before processing for motion detection".

In your case ZM should ignore the entire screen change that happens on the connection drop out. I've played around with this setting using a camera in a dark room. If I turn the light on and then off before the number of ignored frames expires I get no alarm or event. If I turn the light on without entering the room (using up the # of ignored frames) then I get an alarm and event that includes the light coming on (the frames are ignored but still buffered). And of course if I enter the room I get an alarm and event that appears to be what ZM would have produced without the setting. With another camera set up in a hallway (no major changes to the environment) motion is detected with expected results.

@bb99 - Thank you so much for this information! I will experiment with this option now to see if I can use it to solve my problem.

For the record, this particular camera is running at 5fps. I assume that setting it to 5 frames will result in 1 second of "ignore" time which should be adequate, but I will have to experiment with exactly how long signal loss bluescreen duration actually is to find an ideal value.

Thank you again!