Dimension and Installation
20
The alarm input port supports alarm signal from ground and device of 12V-24V voltage.
If the alarm device is connected to the Device and other devices, use relay for isolation.
Alarm Output
The alarm output port cannot be connected to high-power load (less than 1A). When
constructing the output circuit, the excessive current should be prevented from causing
damage to the relay. Use the contactor for isolation when applying high-power loads.
PTZ Decoder Connection
The common-ground must be prepared for PTZ decoder and the Device; otherwise the
common-mode voltage might not be able to control the PTZ. It is recommended to use
shielded twisted pair, and the shielding layer can be used for common ground.
Prevent interference from high-voltage power, make reasonable wiring, and take measures
for lighting protection.
Parallel connect 120Ω resistance to reduce reflection and ensure high signal quality.
The Device RS-458 A line and B line cannot connect to other RS-485 output device in
parallel.
The voltage between the A line and B line must be less than 5V.
Front-end Device Grounding
The bad grounding might result in chip damage.
No restriction for types of alarm input
The alarm input can be Always On or Always Closed.
2.5.1 Alarm Input Type
Describes alarm input and output ports.
Alarm input/output port
Figure 2-26
Name
Function
1
–9
Alarm input 1~9, where 1~8 are local alarm input, 9 is a combination of
impulse and alarm (but only one function, impulse or alarm, can be
used)
