Dahua D-XVR8208A-4K-I, Руководство пользователя

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Connecting Basics 15
Make sure the front-end device has soundly earthed
Improper grounding might result in chip damage.
4.3.1 Introducing Alarm Port
The alarm input ports are dependent on the model you purchased.
Figure 4-2
Icon Description
1
，
2
，
3
，
4
，
5
，
6
，
7
，
8
，
9
，
10
，
11
，
12
，
13
，
14
，
15
，
16
ALARM 1 to ALARM 16. The alarm becomes active in low voltage.
NO1 C1, NO2 C2,
NO3 C3
There are four groups of normally open activation output (on/off button).
Ground cable.
485 A/B
485 communication port. They are used to control devices such as
decoder.
120Ω should be parallel connected between A, B lines if there
are too many PTZ decoders.
Table 4-1
4.3.2 Alarm Input
Refer to the following figure for more information.

Grounding alarm inputs which includes NO (Normally Open) and NC (Normally Closed)
type.

Parallel connect COM end and GND end of the alarm detector (Provide external power to
the alarm detector).
 Parallel connect the Ground of the DVR and the ground of the alarm detector.

Connect the NC port of the alarm sensor to the DVR alarm input (ALARM).
 Use the same ground with that of DVR if you use external power to the alarm device.