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3.3.3.2 Audio Output Connection Information
The audio output signal
parameter is usually over 200mv 1KΩ (BNC or RCA).
It can directly connect to a low impedance earphone, active speaker, or amplifier-drive audio output device.
If the speaker and the microphone cannot be separated spatially, it may create a feedback loop. In this case you
can adopt the following measures:
•
Use a better directional microphone.
•
Reduce the volume of the speaker.
•
Using more sound-absorbing materials in the surrounding area can reduce voice echo and improve the
acoustic environment.
Adjust the layout of the audio output cables to reduce the occurrence of a feedback loop.
3.3.4 Alarm Input/Output Connections
Please read the following before connecting any alarm devices
3.3.4.1 Alarm Input Connection Information
a.
Please make sure the alarm input mode is grounded.
b.
A grounding signal is needed for alarm input.
c.
Alarm input uses a 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 one DVR and one other device, please use a relay to separate them.
3.3.4.2 Alarm Output Connection Information
The alarm output port should not be connected to a high-power load directly (The power load should be less than
1 amp) to avoid high current which may result in relay damage.
3.3.4.3 Connecting a PTZ Decoder
a.
Ensure that the decoder has the same grounding with the DVR, otherwise you may not be able to control
the PTZ. Shielded twisted wire is recommended and the shielded layer is used to connect to the ground.
b.
Avoid high voltage. Ensure proper wiring and take some thunder protection measures.
c.
For signal wires that are too long, 120Ω should be connected in parallel between A, B lines on the far end to
reduce reflection and guarantee the signal quality.
d.
“485 A, B” of DVR cannot parallel connect with “485 port” of another device.
e.
The voltage between the A,B lines of the decoder should be less than 5v.
3.3.4.4 Alarm Input/Output Details
Important!
Please refer to the specifications for the alarm input and output channel amount. Do not merely count the alarm
input and output channel amount according to the ports on the rear panel.
