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issues to notice.
1. Do not stay in the turn-on state for a long time.
2. Keep the computer display normal working by demagnetizing
regularly.
3. Stay away from the electromagnetic Interference.
TV is not a credible replacement as a video output. It demands reducing
the use time and control the power supply and the interference introduced by
the nearby equipments strictly. The creep age of low quality TV can lead to
the damage of other equipments.
2.5.3 Audio signal input
Audio port is BNC connection.
The input impedance is high so the tone arm must be active.
The audio signal line should be firm and away from the electromagnetic
Interference and connected credible which avoid false and joint welding and
oxidation. The high voltage current should be avoided especially.
2.5.4 Audio signal output
Commonly the output parameter of DVR audio signal is greater than 200mv
1KΩ (BNC) which can connect the low impedance earphone and active sound
box or other audio output equipments through power amplifier. If the sound box
and the tone arm cannot be isolated, howling phenomena is often existed. There
are some methods to deal with the above phenomena.
1.
Adopt better directional tone arm.
2.
Adjust the sound box volume to be under the threshold that
produces the howling phenomena.
3.
Use fitment materials that absorb the sound to reduce reflection of
the sound.
4.
Adjust the layout of the sound box and the tone arm.
2.6 Alarm input and output connections
1. Alarm input
A.
Alarm input is grounding alarm input.
B.
Alarm input demand is the grounding voltage signal.
C.
When the alarm is connected with two DVRs or connected with
DVR and other equipments, it should be isolated by relay.
2. Alarm output
Alarm output cannot be connected with high-power load (no more than
1A).When forming the output loop it must prevent the big current from
relay damage. Use the contact isolator when there is a high-power load.
3. PTZ decoder connections
A.The grounding of the PTZ decoder and DVR must be shared
otherwise the common-mode voltage will lead to the PTZ control failure.
The shielded twisted pair is recommended.
B. Avoid the entrance of high voltage. Make the layout reasonably.
Take precaution from the thunder.
C. In the outlying end connect 120Ω resistance paralleled to reduce the
inflection and insure the signal quality.
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