In IP CCTV systems , each component has an individual IP address. IP addresses are in the format xxx.xxx.xxx.xxx where each block of xxx can be any number between 0 and 255.
IP CCTV systems are, apart from the monitor, connected using network cables, commonly referred to as Ethernet or CAT5 cables. The network cables are terminated with RJ45 male plugs. Connecting the cameras to a Network Video Recorder (NVR) or a router requires the network cable to be a ‘Straight’ type. Connecting IP cameras directly into a router is not the recommended way to set-up a ‘proper’ CCTV system. Using an NVR gives far greater control of the recording, storage and playback facilities.
The maximum network cable length between cameras and the NVR is 100 metres.
Power to the cameras on the system can supplied locally to the cameras or use power over Ethernet (PoE)
Local Power to Cameras
Dome, Eyeball and Bullet IP CCTV cameras require a supply voltage of 12v + 10%, and typically require a maximum of 8 Watts (670mA @12v) of power. The power supply should be from a regulated/stabilised source. You should be aware of voltage drop in long cable runs when powering cameras locally. Voltage drops can be minimised by using thicker cable or if using multi-core by doubling up on the power cores.
PTZ (Pan, Tilt & Zoom) cameras require significantly more power – typically 24vAC and 50 Watts (2.1 Amps).
PoE (Power over Ethernet)
One of the main advantages of IP systems is the ability to use PoE in which the cameras are powered from a PoE enabled network connection using the Non-PoE enabled cameras can still be powered locally and still be connected into a PoE enabled network port without any damage to the camera. See the article How to use PoE in IP CCTV Systems for a more detailed explanation of PoE.
NB: PTZ cameras require more power and should use PoE+. PoE+ has more power available.
There is a lot of flexibility in the interconnection of IP CCTV systems. This is because IP CCTV systems use IP addressing for the components.
Simple Connection Scheme – PoE Ports on the DVR
In the simplest setup, shown below, we have a 4 channel NVR with 4 PoE enabled ports. Each port has 1 PoE enabled camera connected. If the cameras are not PoE enabled then the ports can still be used and the cameras can be powered locally. The LAN port is connected to a router which also connects the system to the local network (LAN) and also to the Wide Area Network (WAN) aka the internet.
The monitor can be connected to the NVR using the VGA connection or by HDMI if the monitor has an HDMI input. Two monitors can be connected – one on VGA and one on HDMI if required. More monitors can be added using VGA and/or HDMI splitters.
Simple Connection Scheme – Using External Port Switch
The previous example used an NVR with the network ports built in to the NVR. Some NVRs, usually less expensive models, do not have the network ports built-in. They are fitted with just a single port, and as such, they require an external port switch. The external port switch can be either a PoE enabled switch or a Non-PoE switch. If a non-PoE switch is used then the cameras will have to be powered locally.
The diagram below shows a typical set-up using a 5 port PoE switch. The switch shown is a 4 x PoE ports + 1 x non-PoE. The non-PoE port is connected into the router as is the NVR. Switches are available in various combinations. For example a 4 x PoE + 2 x non-PoE could be used and the NVR and the Router connected into the non-PoE ports.
Complex Connection Scheme
The above two examples should be easy enough to understand and are based on only a 4 channel system. The example below shows a far more complicated system using a 16 channel NVR. The Hikvision DS-7608NI-E2/8P/A is fitted with 8 PoE ports and one standard Ethernet port. The remaining 8 channels are accessed through the Ethernet port using switches which may be PoE or Non-PoE types. A separate power supply is needed when Non-Poe switches are used.
The diagram above is only one example out of hundreds of possible configurations.
A non-PoE camera can be connected to a PoE port without damaging the camera.
If the output from a PoE port is connected to a non-PoE port switch, the power is not passed through the switch. I.e. PoE cameras have to be connected to a PoE port as the last connection to the camera.
A PoE enabled camera can be connected to a non-PoE port and the camera then powered locally.
The power output from a PoE port cannot be used to directly power a Non-PoE camera – a PoE splitter has to be used. The voltage from a PoE port is 48 volts and will fry a 12 volt camera.