HIKVISION DS-7216HGHI-K1 User Manual page 164

3. The control protocol is not correct.
Solution
1. Check if RS-485 cable is properly connected.
2. Change RS-485 interface, and try again.
3. Ensure control protocol is Pelco.
13.5.16 Why is the video sound quality not good?
Reason
1. The audio input device does not have a good effect in sound collection.
2. Interference in transmission.
3. The audio parameter is not properly set.
Solution
1. Check if the audio input device is working properly. You can change another audio input
device, and try again.
2. Check the audio transmission line. Ensure all lines are well connected or welded, and there is
no electromagnetic interference.
3. Adjust the audio volume according to the environment and audio input device.
Digital Video Recorder User Manual
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