Alarm Output Port - Dahua NVR21-4KS3 Series User Manual

● There are two alarm input types: NO/NC.
● When connect the ground port of the alarm device to the NVR, you can use any of the GND ports
( ).
● Connect the NC port of the alarm device to the alarm input port (ALARM) of the NVR.
● When there is peripheral power supplying for the alarm device, please make sure it is earthed
with the NVR.

2.3.3 Alarm Output Port

● There is peripheral power supplying for the external alarm device.
● In case overload might result in NVR damage, please see the following relay specifications for
detailed information.
● A/B cable of the RS-485 is for the A/B cable connection of the speed PTZ.
Figure 2-119 Alarm input port (2)
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User's Manual