FIELD GUIDE TO DVR'S: dvr troubleshooting checklist
Problem: DVR failed to record an event.WHAT TO CHECK: Failure to record can be caused by many factors. The first things to check are the basics:
- Is the camera working?
- Was there sufficient light?
- Was the DVR working?
- Are all cables properly connected?
If the DVR is programmed to record on a time-schedule basis, verify that the event occurred during the scheduled record time. If the DVR is programmed to record based upon alarm input only, then check to see that the alarm input settings were properly configured and that the alarm input was indeed activated.
If the DVR is programmed to record based upon motion only, then check to see that the motion detection settings were properly configured. These settings may include a number of factors such as amount of scene change, masking blocks, and sensitivity. In order for motion to activate the DVR, the motion must exceed the settings.
Problem: DVR does not meet expected storage timeWHAT TO CHECK: The storage capacity of a DVR is dependent upon a number of factors such as image quality, frames per second, hard-drive capacity, compression rate, and motion/time settings. When designing a DVR system you should carefully consider all of the factors in order to properly size the drives for the DVR. If the system is not meeting the intended storage capacity, then you should check to see if any of the controllable parameters such as image quality, frames per second, motion/time settings, etc., have been changed. Depending upon the options available for the DVR being used you can try to alter the following parameters:
- Consider recording on motion only. If currently set to record by schedule only or record at all times, changing to record only on detection of motion will greatly increase the time stored, since recording will only be done when motion is detected. If you must record by schedule it may be possible to reduce the frames per second or record only on motion during the normally closed period.
- Reduce the number of frames per second that are recorded. A setting of 5 frames per second will use much less disk space than a setting of 15 frames per second.
- Reduce the image quality. Changing from an image file of 30K to 15K will dramatically increase storage time. As with frame rate, if this setting is on a per-camera basis, then consider reducing the image quality for non-critical cameras.
Problem: Why do the images displayed on the DVR screen look poor, but if I connect the camera directly to an analog CCTV monitor they look good?WHAT TO CHECK: First make sure that you have properly set all of the camera parameters, such as camera type (color/B&W) and NTSC/PAL, and that all cables are properly connected on the DVR. If you are using any looping connections, then check to see that all of the input terminations are properly set at each device. It is also possible that the video signal level is incorrect. Most DVRs require a 1 volt peak-to-peak video signal while an analog CCTV monitor can frequently provide a good image when the video signal is very low. You should also remember that the image quality being displayed may be low due to the quality of the DVR screen. Since this is the screen used to view images you should only use a high-quality screen for the DVR.
Problem: Why do some or all of the cameras not properly respond to PTZ commands from the DVR?WHAT TO CHECK: First verify that the cabling and camera are working properly. To do this you can connect the appropriate PTZ joystick controller directly to the cameraâ€™s control cable. If the camera responds properly you can check the following:
- Is the PTZ camera/format supported by the DVR being used?
- Is the correct COM port selected (if applicable) in the DVR configuration? Are the correct addresses set at the cameras and DVR? Was any required format converter installed?
- Are all of the PTZ cameras using the same format? Some DVRs will only support one PTZ format for all cameras in the system.