NVR User Manual
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displays can be used as external display devices.
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To ensure the quality of images, use dedicated monitors.
Note the following when you use computer displays or televisions as monitors:
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Ensure proper grounding. Low‐quality computer displays or televisions have electric leakage
hazards, which may damage other devices.
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Perform degaussing regularly to ensure proper operating of the monitors.
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Keep the monitors away from devices that generate strong electromagnetic interference.
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Power off the device after operating for a period to extend the service life of the device.
2.5 Audio Input and Output Connections ﴾AIN and AOUT﴿
Generally, the audio output signal parameter of the NVR is larger than 200 mV 1K. The NVR can be
connected to external low‐impedance headsets and active sound boxes directly or connected to other
sound output devices through power amplification drives.
When the NVR is not isolated from external sound boxes or audio monitoring units, output squealing
may occur. In this case, take the following measures:
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Adjust the volume of the sound box to be smaller than the threshold at which output squealing
occurs.
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Adjust the layout of the audio monitoring units and sound boxes.
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Use sound‐absorbing materials during decoration to reduce the reflection of sound and improve the
acoustic environment.
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Use audio monitoring units with superb directionality.
2.6 Alarm Output Connections
1. Alarm output interface ﴾one alarm output﴿
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As shown in the figure, COM1 is the common ground terminal, NC1 is the normally closed output
terminal, and NO1 is the normally open output terminal.
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Power supplies must be connected to external alarm devices for the Boolean alarm output ﴾NO
contact﴿.
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Grounding alarms are generated when the alarm circuit is directly connected to the ground.