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E. The voltage between the AB lines of the decoder must be less than 5V.
4. Front equipment grounding note
Bad grounding can lead to the burnout of the chip.
5. Alarm input type unlimited
The DVR alarm output port is constant opening type.
Eight external alarm interface
(1) alarm input 1,2,3,4
(2) ground (3) RS232 (4) RS485 (5) alarm input 5,6,7,8
(6) ground (7) alarm output
2.7.1 Alarm input port specification
8 channels alarm input. Alarm input type unlimited.
The grounding and the com port of the alarm sensor are parallel (The alarm sensor is external
power supply) .
The grounding of the alarm and the DVR should be shared.
The NC port of the alarm sensor must be connected with the DVR alarm input port.
The grounding of the power supply and the alarm sensor must be shared when used in external
power supply.
2.7.2 Alarm output port specification
2 channels alarm output. There is external power supply when using the external alarm equipment.
