21
c. For too long signal wires,
120Ω should be parallel connected 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 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 has soundly earthed.
Improper grounding may result in chip damage.
3.7.1 Alarm Input and Output Details
Alarm input and output interface is shown as in Figure 3-12.
Please note the alarm input interface definition is pre-defined.
Figure 3-12
Please refer to the following sheet for detailed information.
SN
Function
1
Alarm input 1(White cable)
Connect to emergency button alarm.
2
Alarm input 2(White cable)
Connect to front door alarm.
3
Alarm input 3(White cable)
Connect to back door alarm.
4
Alarm input 4(White cable)
Connect to the left-turn alarm.
5
Alarm input 5(White cable)
Connect to right-turn alarm.
6
Alarm input 6(White cable)
Connect to brake alarm.
7
Alarm input 7(White cable)
Connect to running status alarm (Running/stop)
8
Alarm ground cable
(
Purple cable
)
9/10
NO output 1
(
Yellow cable
)
11/12
NO output 2
(
Yellow cable
)
3.7.2 Alarm Input Port
Please refer to the following sheet for more information. See Figure 3-13.
Normal open or Normal close type.
Please parallel connect COM end and GND end of the alarm detector (Provide external
power to the alarm detector).