NVR Model: DHI-NVR4832-I
NVR Version: No specific version restrictions
IPC Model: HFW5442EP-EZ
IPC Version: V2.800.0000000.0.R Built Date: 2019-05-21
Description of the problem
The customer want to capture one picture when the local alarm is input to the IPC, the IPC’s firmware used to work but when the customer upgrade the latest firmware, the camera can’t ensure capture only one picture(customer check this in playback interface of NVR). So the customer guess the problem is in IPC and ask Dahua to provide help.
Problem Processing (Root Cause)
There are two possible situations:
1. the IPC send several pictures to NVR when the local alarm is input.
2. The NVR affects IPC lead to IPC send several pictures to NVR.
At this situation, we need FTP software to confirm the reason. The FTP software can record the picture from the IPC and NVR directly so that we can confirm that how many pictures are sent by the IPC and how many pictures are received by the NVR.
The result of test showed that IPC only record one picture in FTP server but NVR can receive three pictures in FTP server . It is weird but we can be suspicious of the NVR affects the IPC lead to this problem.
Finally, the RnD colleagues analyze the capture packets which I provided and confirm the problem is in NVR. The root cause is the NVR will send a wrong command to IPC lead to IPC will send several pictures back to NVR when the local alarm is input.
Submitting a ticket in Weor system to customize the firmware to solve this problem. Regarding the baseline firmware, RnD said this problem will be solved in the new UI version Firmware.
Add a note: In normal situation, how to configure the IPC or NVR to ensure capture only one picture when the local alarm is input.
: Mechanism Introduction
This feature mainly depend on IPC, the NVR is only received pictures from IPC, so the most important thing is configure the IPC correctly. The mechanism of capture pictures in IPC as follow:
If the local alarm will be enabled for a short time(≤ 2 seconds), we can set the “anti-Dither time”=0 and set the “Interval time”=3 seconds, at this time, the IPC will only capture one picture when the local alarm is input.
Anyway, only when the “Interval time ”≥the “Entire event time”, the capture picture number=1.
 Step by Step Instructions(in IPC)
1. Enable the function and set the Anti-Dither = 0
1. Select the snapshot type to Event and set the Interval to 3s