Dahua NVR21-4KS3 Series User Manual page 77

No. Port Name
1 Network port
2 MIC OUT
Alarm input port
(1-4)
NO C
CTRL
3
P
4 Power button
5
6 USB port
7 MIC IN
8 VGA port
9 HDMI port
10 Power input port
Table 2-38 Ports
Function
10/100/1000 Mbps self-adaptive Ethernet port. Connect to the
network cable.
Audio output port. It is to output analog audio signal to devices
such as sound box.
● Bidirectional talk output.
● Audio output on 1-window video monitor.
● Audio output on 1-window video playback.
● They receive signals from external alarm source. Alarm
input includes two types; NO (normal open) and NC (normal
close).
● When your alarm input device is using external power,
make sure the device and the NVR have the same GND.
GND. Alarm input ground port.
One NO activation output group. (On-off button).
Controllable power supply output. Control the
output of the on-off button alarm relay. It controls
the alarm device with the presence or absence of
voltage. It can also be used as power input for some
alarm devices such as alarm detectors.
Power output port. It can provide power to some
peripheral devices such as camera and alarm device.
Make sure the power supply of peripheral device
shall be below 1 A.
Turns on/off the NVR.
GND.
USB 3.0 port. Connect to devices such as mouse, USB storage
device and USB burner.
Bidirectional talk input port. It is to receive analog audio signal
from devices such as microphone, sound pickup.
VGA video output port. Output analog video signal. It can
connect to the monitor to view analog video.
High definition audio and video signal output port. It transmits
uncompressed high definition video and multiple-channel
audio data to displays with HDMI port.
Input power of 100-240 V and 50-60 Hz.
57
User's Manual
The
two
ports
serve as
another
group
of
alarm
output
ports.