Advanced Manual

Table Of Contents
3-45
Alarm Cable
Twisted pair cables are recommended. The cable should range from 22 AWG to 28 AWG (24 AWG
and 26 AWG are recommended). The direct current (DC) impedance must not be more than 100 ohm.
The following table shows the maximum length for different cables, taking 100 ohm as the maximum
impedance.
Table 3-6 Maximum Length for Different Alarm Cables
Specifications (AWG)
Maximum Length (m)
22
1453 m (4767.06 ft)
24
914 m (2998.69 ft)
26
570 m (1870.08 ft)
28
360 m (1181.10 ft)
Network Cable
Network cables are mostly made from twisted pair cables, which are the most commonly used in
cabling. Twisted pair cables includes unshielded twisted pair (UTP) cables and shielded twisted pair
(STP) cables. An STP cable has a layer of bonded aluminum foil to reduce radiation. STP cables are
more expensive than UTP cables, and STP cable installation is more difficult than UTP cable
installation.
Optical fiber
The optical module in the camera should match that of the third-party device (such as a switch), in
terms of fiber mode and emission/receiver wavelength. Ensure the transmission distance of the
optical module is greater than the distance actually required.
Ensure that the following requirements are satisfied when connecting two devices using an optical
fiber:
When an SFP optical module is connected, the curvature of the optical fiber should be greater
than 90 degrees.