Security Sensors

------------- found some ultrasonic since I wrote this --- But if any of you have some options I would be interested in knowing about them

We use one of our PLC 5/20s for security in addition to other control functions.

We also send signals to a Hikvision NVR via a 1771-OW16. It captures an image of the detection zone and sends it to our email, DropBox image directory, phones etc.


We have been looking for another sensor to provide outdoor intrusion detection in an area. PIRs either send tons of nuisance alarms or don't trip when they should.

We prefer something like that but have not found a PIR that is good for security.

IR is not really what we want. We want to use something that detects something moving in a zone. I have heard of some sonic devices using inaudible signals but have not found any.
Anybody have some ideas?



Thank you!

Doesn't your NVR include motion detection?? Most of them do.

Most of the quality motion detection sensors provide a digital out that can be programmed at what level of detection to trigger. Example: A Large 200 Lb. person or a small 3 Lb. cat and anything in-between. Just check out the sensors that are designed for "Security".

mendonsy said:

Doesn't your NVR include motion detection?? Most of them do.

Click to expand...

Well yes, they are not really motion. They are "scene change" The better ones don't use PIR they monitor the pixels in a grid and alarm based on a threshold of number of pixels changed in the grid and how much time elapsed between change. A change of one grid in a short time, based on the sensitivity setting may or not trigger an alarm. You can set them to not monitor some areas like Trees. Snow and spiders crawling across the lens or any small particles wizzing by the camera at night causes lots of nuisance trips.

They are not the best solution either in a base system. If you buy some advanced software to run on another machine you can fine tune it much more,

We use several solutions to monitor areas and driveways. Some like laser eyes for barrier crossing at an entrance.

We want to monitor a large area not just a crossing point.

damica1 said:

Most of the quality motion detection sensors provide a digital out that can be programmed at what level of detection to trigger. Example: A Large 200 Lb. person or a small 3 Lb. cat and anything in-between. Just check out the sensors that are designed for "Security".

Click to expand...

Thank you for your suggestion.

I have looked at tons of them. Tried several. Anything I have seen that uses PIR is very untrustworthy.

Perhaps you know of some higher end that will do what I want. I have not found any that are reliable without giving too many nuisance alarms.

You may very well be correct, I have used several - but never as you suggest.

But here is a manual of one that might be worth a try. As you can see by reading the manual it might require some very fine tuning.

The security companies that provide a monthly monitor fee have this feature fine tuned as they would not want false alarms either.

Keep us posted on your solution.

Thanks

https://www.axis.com/files/manuals/um_t8331_series_1518265_en_1511.pdf

Thanks for that info David, Axis is pretty reputable. Some of there various PIR sensors just may do what we want. We want these for 24 hour security. We want 4 or 5 so I am going to call Axis and talk to an application engineer and see about testing.

Thank you very much!