Dahua HDCVI FAQ, As the inventor of HDCVI (High Definition Composite Video Interface) technology, Dahua continuously invests in the technology to rejuvenate existing coaxial-based systems since its launch in 2012 with its own patents. As the first to bring 4K resolution over coax, the first to introduce IoT into analog monitoring, and with versatile offerings such as multi-sensor and fisheye cameras,
Dahua has formulated its HDCVI camera selection as the perfect choice to strengthen your existing coaxial system. Dahua HDCVI cameras are separated into the Pro, Lite and Cooper Series, which range from high performance with project oriented features to a cost/performance balance. Users can select cameras based on their needs. HDCVI cameras are used in applications where existing analog infrastructure is available and users have a need for the latest technologies, including 4M/4K resolution, IoT over coax, Power over Coax (PoC), and more.
Image #
Check whether the power supply is connected and use a multi-meter to measure whether there is voltage. If the voltage is normal, check whether the video cable is in good contact.
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Check whether the video cable is in good contact and whether the outgoing cable of the video input port is welded well.
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Check whether the B\W mode is set in the menu or the camera is installed in a dark corner.
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Check whether the camera is installed correctly. If the installation is correct, check whether the mirror function in the menu is on.
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First, check whether the video format parameters of the camera is modified, then check whether the output mode of the back-end DVR matches the camera and cannot be lower than the output resolution of the camera.
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The motorized vari-focal lens is not fixed, and will drop due to vibration during the transportation, and the image will change. The user can perform automatic focusing once to restore it when using it.
Dahua HDCVI FAQ #
Test them by using a focus card and verify whether the products conform to the ex-factory requirements. If yes, they are normal.
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Check whether the image parameters in the menu are modified, perform the “restore default verification”, and then check whether the image configuration parameters of DVR are default.
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Check whether the video cable contacts well and is oxidized.
If a centralized power supply is used, disconnect other circuits and only keep one camera working to see whether there is any interference.
If this is caused by centralized power supply, use a single power supply or Dahua’s centralized power supply. For products with low power consumption (less than 5W), perform power supply isolation.
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Check whether the video cable and casing of the camera contact the elevator or not. The camera shall be installed to avoid interference of elevator signals.
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Restore the camera parameters to the default first. If there is still fuzzy stains, adjust its noise reduction parameters and lower the level until the fuzzy stains is acceptable.
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Restore the camera parameters to the default first. If there is still image noise, adjust its noise reduction parameters and increase the level till the noise is acceptable.
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Firstly, check the coding parameters of the back-end XVR, and set the coding to have the real-time frame rate (PAL system 25fps, NTSC system 30fps), and the variable stream or stream to the maximum value. If there is still fuzzy stains, set the image noise reduction parameter to 50 by default, and lower the value till the fuzzy stains is acceptable.
IR #
First, use a multi-meter to measure the working voltage of the camera at night. At night, when the IR is on, the power consumption increases and the voltage will decrease. If it is lower than the lower limit of the rated voltage, the device will not work normally. Then, increase the voltage at the input.
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Check whether the camera is an IR camera. For ordinary cameras without fill light, the image is darker at night; for IR cameras, check whether the IR light is on, whether it is in black-white mode, and whether ICR will be switched.
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If it is a non-photosensitive product, check whether there is any obstacle right in front of the camera installation position.
If it is a photosensitive product, check whether there is any flashing strong light source or other IR light sources in the monitoring scenes.
Remove the cover to see if the image still has circular arc shadow. If not, reassemble the aperture stop and cover, and then check whether the shadow disappears. If any, replace the device for maintenance.
Power supply #
The label of the camera will indicate the power type, such as 12V DC, 12V DC / 24V AC; then select a power supply larger than the rated current marked on the label according to the current.
When the battery identification flashes, the working voltage of the camera exceeds or falls below the rated voltage. Check whether the power supply is normal.
The camera is connected to the power supply and is in a working state. Use a multi-meter in the current measurement mode, and connect the multi-meter in series to the circuit to measure the working current.
The camera is connected to the power supply and is in a working state. Use a multi-meter in the voltage measurement mode, and connect the multi-meter in series to the circuit to measure the working current at both ends of the power supply.
Menu #
First, set the PTZ parameters and mainly select HDCVI coaxial protocol. Click “Aperture +” to enter the menu and select parameters by pressing the upper, lower, left and right keys.
Enter the camera menu, in the “System” option, switch left and right, select the system you want and exit to save settings.
If the camera has a DIP switch, switch modes according to the switch diagram; if the camera does not have a DIP switch and supports four modes, switch them by selecting them in the advanced options in the menu or by external UTC.
The back-end DVR sends commands to the front end all the time, which leads to this problem. Disconnect the video cable to check whether they still jump. Then restart the back end or set the back-end parameters to the default.
One thing that should be clear is that coaxial cameras do not have a hardware reset button.
Method 1: Go to the OSD menu and select default to restore to factory settings.
*When you use OSD menu to restore the device to default settings, the resolution, mode, frame rate and language of the device will not be restored.
Method 2: Upgrade the camera’s program and the device automatically restores the default.
*The upgrade is normally done on the back-end control page.
Water mist #
Check whether there is any crack in the screw hole of M bullet camera. A batch of products are manufactured with fake materials, and the crack in the screw allows water to enter the device.
If the image is clear-fuzzy-clear in a full-color environment, check the front glass of the protective cover for fogging at night; if due to water mist, add desiccant onto the shield and ensure that the waterproof performance of the shield reaches the standard.
Basic problem #
75-5/75-3 video cables are preferred in the domestic market and RG59/RG6 video cables in the overseas market. If twisted pair transmission is selected, add a pair of balun for access to cameras and DVRs, and connect the sending terminal at the BNC head of the camera and the receiving terminal at the BNC head of the DVR.
This depends on the output pixels of the camera, as shown in the following table:
The smaller the focal length of the lens, the larger the field angle, and the shorter the monitoring distance. Refer to the following figure (Numerical values are for reference only). Refer to the product manual for specific project selection).
View the image together when adjusting the sunshade cover. For IR cameras, when the IR is on, no white bright shadow appears above the image.
For non-IR cameras, no shadow shall appear on the image.
There is no certain requirement, and it depends on the actual monitoring scenes of customers. The height is preferably above 3 meters, and there should be no large obstructions, such as walls or trees, in front of the camera installation position.
Install the junction box. Place the cable connection inside the waterproof box. Generally, the way of pipe threading is preferred for installation, and the cable joint is wrapped with black insulation adhesive, which has a general waterproof effect.
Cameras with multiple outputs have four modes of CVI/TVI/AHD/CVBS; the first three are coaxial HD signal and the last one is analog SD signal.
Transfer the UTC switching module to the video cable. Connect one section of UTC to BNC output of the camera, and the other end to the video cable, which is then connected to the video input terminal of XVR.
For cameras with audio function, set headphone or external audio function by entering the Menu – Advanced Settings – Audio Mode, while the back-end DVR access channel turns on the coaxial audio function.
First of all, confirm the method to fix screws – manually or by power tools, whether the torque exceeds the requirements. If loose screw is caused by using normal torque, return the faulty product for material analysis.
Description of the Problem:
2 identical HDCVI cameras connected to the XVR, both support a maximum frame rate of 15 fps, but the actual use of one of the highest rate can only reach 8 fps
Solution and Conclusion:
The frame rate set on the first channel is too high resulting in insufficient frame rate on the following channels. Recommend that decrease the frame rate of the first channel.
