JF TECH JRC-27F, Руководство пользователя

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the use of time and strictly controls the interference power caused by neighboring
devices. Inferior TV leakage risks may cause damage to other equipment.
2.6.3 SDI video output
Some models support coding for 1080P (720P) SDI video.
2.6.4 Audio input
BNC connector (only one to support intercom function)
Audio input impedance is high, and therefore must be used active pickups.
Similar to the video input audio transmission requires line to avoid interference, avoid
Weld, poor contact, and special attention to prevent a string of high-voltage current
into.
2.6.5 Audio output
Audio output signal parameters is generally greater than 200mv 1KΩ (BNC), you can
directly connect the low impedance headphones, powered speakers or other sound
through power amplifier output devices. In the case of external speakers and
microphone cannot be achieved spatial isolation, it is easy to produce output howling
phenomenon. At this point the measures to be taken are:
1.
The use of directional better pickups;
2. Adjust speaker volume, making it lower than the threshold to produce the whistle;
3. Multi-use environment using sound-absorbing materials decoration, reduce the
reflection of the sound, improve the acoustic environment;
4.
Adjust the layout of pickups and speakers, but also can reduce the occurrence of
howling situations.
2.7 Alarm input and output connections
Before connecting the device, please note the following:
* Note: Some Series devices without alarm input and output functions.
2.7.1 Alarm Input
Alarm input is grounding alarm input;
Alarm input requirements for ground voltage signal;
When the alarm is connected to two DVRs or simultaneously access the DVR or DVR
and other devices, need to be isolated by relay.
2.7.2 Alarm Output
DVR alarm output cannot be connected power load (no more than 1A), should
constitute the output loop current is too large to prevent damage to the relay. Require
the use of high-power load contactors isolation.
2.7.3 PTZ decoder connected
A. must do PTZ decoder and DVR common ground, otherwise there may be
common-mode voltage will lead to control PTZ. Recommended to use shielded twisted
pair with shielding for common ground connection;
B. prevent high voltage in series, rational layout, good lightning protection measures
C. to be incorporated into the 120 ohm resistor in the remote reduced reflection, to
ensure signal quality;
D. DVR 485 AB line cannot be connected with other 485 output;