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3.6 Alarm Input and Output Connection
Refer to the following sheet for alarm input and output connection.
You can select two alarm input types: Normal Open (NO) and Normal Close (NC).
1. Alarm input
a. Make sure alarm input mode is grounding alarm input.
b. Grounding signal is needed for alarm input.
c. Alarm input needs the low level voltage signal.
d. Alarm input mode can be either NO (Normal Open) or NC (Normal Close).
e. When you are connecting two DVRs or you are connecting one DVR and one other device, use a relay to
separate them.
2. Alarm output
The alarm output port should not be connected to high power load directly (It shall be less than 1A) to avoid high
current which may result in relay damage. Use the contactor to realize the connection between the alarm output port
and the load.
3. How to connect PTZ decoder
a. Ensure the decoder has the same grounding with DVR, otherwise you may not control the PTZ. Shielded
twisted wire is recommended and the shielded layer is used to connect to the grounding.
b. Avoid high voltage. Ensure proper wiring and some thunder protection measures.
c. For too long signal wires, 120
Ω
should be parallel connected between A, B lines on the far end to reduce
reflection and guarantee the signal quality.
d. RS 485 A, B of DVR cannot parallel connect with “RS485 port” of other device.
e. The voltage between of A, B lines of the decoder should be less than 5v.
4. Please make sure the front-end device is linked to ground
Improper grounding may result in product damage.
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