Frequently Asked Questions

This section will cover some of the questions we have been asked with regards to our Silverline DVR's and cameras as well as general CCTV installation.

How Much Power do my Cameras Require?

The amount and type of power your camera will require will vary from camera to camera. Most of the cameras we stock require a 12V DC power supply although some have dual voltage 12/24V adapters built in and some cameras require 230V AC power. The voltage of the camera you need will vary depending on the installation but most of our customers use 12V DC cameras due to the fact that high voltage 230V cameras require a qualified electrician to provide a link to the mains. It is very important that you do not supply a higher voltage than the camera is rated for as this will blow the board and the camera will be useless.

Once you have found out the voltage of your cameras you will need to find out their power consumption. All of our cameras listed on this website and in our catalogue have the power consumption listed in the technical specifications. This information should also be available in any accompanying paperwork in the camera box. Unlike voltage, you can supply the ampage in excess of what the camera needs as it will only take what it needs. When specifying your installation be sure to make note of what cameras you are installing, what voltage they need to be and how many there are so that you can choose an appropriate power supply .

Power supplys are needed whenever you are using a 12V or 24V camera to transform the 230V from the mains to the appropriate voltage. The PSU's are available as individual plug in units up to 1 Amp (1000mA) suitable for single cameras and as metal boxed power supplys up to 4 Amp suitable for powering multiple cameras.

E.g. - An installation with 8 internal colour 12V dome cameras each comsuming 200mA would require the power supply to be able to provide 200mA to each of the 8 cameras. Therefore you would need at least 1.6Amp (1600mA) to power all the cameras. In this case you could use a 12V 2Amp metal boxed power supply unit (PS102S).

What Cable Should I Use For Video and Power Transmission?

Historically, RG59 coaxial cable has been used to transmit the 75ohm video signal from CCTV cameras to multiplexers, VCR's or DVR's and separate 4 core shielded cable has been used to transmit the 12V and 24V power. The introduction of RG59+2 or "Shotgun" cable has made installations not only more convenient but much tidier as well. RG59+2 is standard RG59 cable with the positive and negative cores for power merged onto the PVC casing. More and more installers are using RG59+2 for runs of up to 80m.

Over the length of around 80m the 75ohm video signal begins to lose consistency when transmitted through RG59 or RG59+2 cable which is where CAT5E cable comes in. An increasing number of installation companies are turning to CAT5E cable for their CCTV applications due to a number of benefits over RG59. The greatest benefit of CAT5E cable is the extended cable runs it allows. CAT5E can be run for about 300m with no signal loss on colour applications and about 600m for mono applications. CAT5E cable has 4 pairs allowing up to 4 cameras to be run down a single cable, 2 cameras with power or 1 camera with power and audio with 1 pair left over. This can obviously reduce cost when cabling large jobs.

CAT5E cable is not compatible with standard RG59 BNC connectors as it changes the transmission signal in order to transmit longer distances so connection to the cameras and the DVR is achieved by the use of Baluns. The balun has a BNC connection on one end and a terminal on the other to connect the CAT5E cable. Baluns are available as individual pairs (one for the camera and one for the DVR) or as 4 channel units.

How Long will my DVR Record For?

Recording times on a Digital Video Recorder depend on 3 factors - hard drive size, recording quality and recording frame rate. The general rule is that the bigger the hard drive, the lower the reocrdign quality and the lower the recording frame rate, the longer the recording time. The trick is to strike a balance between these 3 factors to give your customer optimum recording time, recording quality and recording frame rate.

Most Police authorities have a set of guidelines they would like businesses to follow when installing CCTV, the most important of which is usally the amount of time stored by the CCTV system. The most important thing to find out before buying any equipment is how long your customer needs to keep footage after it has been recorded (most of our customers find that their customers want to store anything from 1 week to 1 month). Once you have ascertained this information you can begin building their CCTV system. Find out what kind of quality they are looking for and if their local Police force have specified a frame rate.

Once you have all this information use our DVR Recording Calculator (which can be found in the Technical Support section of this website) to find out what size hard drive you will need and and what frame rate you can record at.

How do Cameras See at Night or in Low Light?

Most day / night cameras make use of Infra-Red technology to see in low light applications. A built in light sensor detects when the light drops below a certain LUX level and automatically turns on the IR light which is invisible to the naked human eye but highly visible to the camera. The IR beam acts as a spotlight that only the camera can see, illuminating the view of the camera. Some cameras are available with built in or bolted on IR illuminators. IR illuminators are available at different strengths, the higher the strength of the IR beam, the farther the camera can see. The Infra-Red signal is sent out from the illuminator and must then bounce off a solid object to be refelcted back to the camera. Therefore, if an IR illuminator with a 25m range is installed and it is 35m to the nearest solid object, the camera will not be able to see anything. If an object such as a person or vehicle passes in front of the camera within 10m of it however, the IR will be able to reflect and the camera will be able to see it.

All the cameras on this website and in our catalogue have their lowest LUX level stated in the technical specifications. The LUX level is basically the amount of light there is available in any application. It helps to know the LUX level of any application you are buying CCTV equipment for before you buy cameras so that you can be sure the cameras you buy will be able to see at all times. We have a digital LUX level meter which can be an essential tool in the Online Store and in the catalogue. Below is a chart to show the LUX level of certain applications.

I Have Set the Frame Rate on My DVR But it Still Fills up in Less Than a Day.

The DVR's in the JPEG2000 range work on schedule recording and not on touch button recording. When the 'Record' or 'Panic/Record' button is pressed, the DVR will begin recording at the maximum frame rate and will not overwrite the files. Once the preliminary hard drive set up has been completed, the DVR will begin recording even if the 'Stop' button is pressed. The only way to stop recording is to go into 'Schedule Setup' in the menu and schedule no recording method. You can tell if the DVR is in Panic Record mode by looking at the on screen display. The very first of the icons on the right hand side of the screen at the top should be a green circle if the DVR is recording at your programmed frame rate but will be red if the unit is on Panic Record mode. Simply press the 'Stop' button or enter and exit the menu.

I Can See The Pictures From My DVR But None of the Buttons Do Anything.

The most likely explanation is that the DVR has been key locked. When the 'K.Lock' button on the front panel of the DVR is pressed, no other buttons can be pressed until key lock has been released. To release the key lock, press and hold down the 'K.Lock' button until the DVR beeps. The unit will ask for the Admin password (blank as default). Enter the Admin password and press the enter button to unlock the keys.

My DVR has a VGA Port on the Back but Will Not Work with a VGA Monitor.

All the Silverline JPEG2000 Advanced Function DVR's have a VGA port on the back but will only be VGA ready if you specified the VGA version when you ordered it. If you need your Silverline JPEG2000 Advanced Function DVR to have VGA capability after it has been delivered or installed, the VGA upgrade card can be bought from the online store and fitted into the DVR quite simply.

I Have set the DVR to Overwrite but the 'HDD Full' Light is on.

Once the hard drive has been filled for the first time the 'HDD Full' light will light up even if the DVR has been set to overwrite. The overwrite feature only records over the oldest data, keeping the hard drive full with data already written instead of wiping the drive completely. You can check that your DVR is still recording by checking the icons at the top right hand corner of the screen. The very first of these icons will be a green circle if the unit is recording.

I Have Installed my Own Hard Drive into the DVR but it Won't Record.

There are a number of factors to consider when installing your own hard drive into the Silverline JPEG2000 DVR. We recommend using Maxtor hard drives as we have found that they are the most reliable drives. If you are installing 1 hard drive, make sure the jumper setting is set to Master. If you are installing 2 hard drives, make sure one of the drives is set to Master and the other is set to Slave. Do not leave both drives on Cable Select as the DVR will not accept them.

Once the drive is installed in the DVR and the DVR is powered up you will need to perform a system reset and clear the hard drives to put them in the JPEG2000 format in order for the DVR to record to them. Once you have completed the format come out of the menu completely and the DVR will begin recordign automatically.