Honeywell (Dahua) NVR Pre-Record Feature Issue/Question

Hi Everyone.

I'm hoping I can find some resolution before proceding to a hardware change.

This is for an 8-camera system at an entry/exit gate and guard house in a private community.

The issue I'm running into is at night when the motion detect recordings are triggered too late (car tail lights etc.) and I only get partial footage of vehicles, license plates and occasionally people. This should be a non issue as in almost all cases I set the pre-record value to 30 seconds, but the pre-record does not seem to occur regardless of what I do.

This system is a combination of a Performance IP NVR and an HQA DVR (LPC cameras) with 3rd party IP cameras and 2 analog Dahua LPC cameras. The video is fine. Sensitivity and threshold settings for motion recordings have been a bear to tune. But mainly, the set up will never work if prerecord is not working as moving vehicle lights trigger the recording too late to get a complete footage of some license plates and cars.

Any suggestion and ideas on how to get this to work properly would be appreciated. Since the pre-record is set at the NVR/DVR level, I'm not sure if non-Dahua/Honeywell cameras would have an impact on this issue.

Thanks in advance for the help.


Alan, how many cameras are doing LPC total? Where do they record, NVR or DVR?

In addition to the pre-record parameter, there is also a record delay parameter in the motion detection settings screen. Is this set to 0?

if it's a night time only problem you could consider scheduling VMD recording during the day and continuous recording at night, though I'm sure you would rather just make it work like it should.

2 LPC cameras recording on a HD-CVI/Analog DVR. Everything else is IP on a Performance IP NVR. Same issue on NVR and DVR. Tech support recommended testing another input on the DVR and then resetting it to default to start over. This dies not make sense since the issue is consistent on all inputs and both recording devices running very similar sofwtare. The recording devices were chosen because they both are compatible with the same mobile CMS (HONVIEW Touch).

The delay settings option is set to the minimum of 10 (10-300 is the range).

It's the same issue for day and night, as well as NVR & DVR. Daytime is not an issue as the gate's motion is readily seen and triggers the recording in plenty of time to capture all that's needed.

Everything works so it seems to be it should be a simple answer, like, "pre-record never works on these devices" or "XYZ camera somehow impairs the feature" or "Don't forget to check ABC setting for it to work"...

The gates are totally dark at night so this problem primarily affects 4 cameras. The exit gate LPC camera is not really an issue as the cars approach this gate slowly and headlight on the gate trigger the recording. The entry gate is triggered open by a keypad much further away so cars go by fairly quickly after the gate has opened (in the dark, motion not triggered). There is a keypad camera so I have use this camera to trigger an alarm from the NVR to the DVR and this helps capture the incoming vehicles' license plates.

The issue is very specific though so I can't imagine I'm the only one to have experienced it.

Thanks for the feedback.

There is a minimum of 10 seconds delay before recording will start on motion? And you are trying to compensate for this with 30 seconds of pre-record?

Am I understanding this correctly?

I don't think the delay is a delay for the recording otherwise I'd have a lot of recordings with no subjects in them. It seems to record when the recording is triggered at exactly the moment it gets the trigger (based on sensitivity, etc.). There's no pre-record buffer at all. I need that pre-record buffer for night time recordings when cars are "flying" by as the lights (head/tail) are what triggers the recording. The effect is that the license plate can be out of the frame already or the car passing by is partially out of the frame or even sometimes completely out of the frame.

As a practical suggestion only, have you considered using a mirror?

I have not. I assume you mean a mirror to reflect ligth to trigger the motion detect recording earlier? If so, in this case I'm not sure where I could place it to make it work that way. Also aesthetically speaking, this is a luxury community so it would look odd and out of place I think.

I have one of those Dahua NVR's and so I messed around with those parameters to see how well the motion detect worked. Also I was thinking that the anti-dither setting might help, but apparently that works like more of a post record.

With both a Dahua bullet and a Trendnet clone the prerecord worked fine all the way to 30 seconds pre-record. I also used an Axis camera just to see, though it made it record all the time.

Maybe it's the Honeywell firmware? Is it the latest?

Instead of a mirror, how about just some reflective tape around a utility pole across the road?

It's odd that I can't get the pre-record to work on the DVR (HD-CVI/Analog) though. I checked the download center for a new firmware and nothing was available. I may have to deal with tech support again but when I initially raised the issue, the wanted me to try different inputs and if that failed reset the recording device and start over. Since both NVR and DVR behaved similarly, I didn't think that was the right way to go.

Is your NVR from Honeywell or straight from Dahua?... The Reflective tape is an option but it would be tricky. The camera is facing towards 11 AM and the cars go by facing towards 1 PM. If the gate is fully open, the headlight would not illuminate anything in the FOV. The trigger becomes the actual tail lights and license plate. Of course that's only one camera. The others are set up differently but are also less critical but still.

It just seems like the pre-record should just work based on the settings and motion detection response.

I do appreciate all the feedback and help.

PS: anti-dither to my understanding is supposed to affect how many events can occur in a given time period. Maybe it also determines the post event record time as well? I have it set at the lowest setting which is 5.

It's a real Dahua. Not one of those cheap American rebrands. ;)

Are you recording/using the extra stream for anything?

What client are you using? I see some people saying that the extra stream doesn't use the pre-record. And if you are checking via mobile that it will use the extra stream?

One other thing, I noticed under Encode that there is a drop down that says Regular/MD/Alarm for each channel, have you seen that too?