Scene illumination : The density of light falling on the area to be viewed. For best results the ratio of the lightest to the darkest areas should not be more than a factor of two.
Screen Formats : Viewing multiple cameras on a single monitor screen. Typical formats are full, 2x2, 3x3, 4x4 and any number of multiple screen divisions.
Screen splitter : A term usually used for a device that can combine the views from two cameras on a single screen. Normally the camera syncs need to be locked together.
SATA : Acronym for Serial Advanced Technology Attachment. This is the cable that connects a PC motherboard to a disk drive or optical drive. It is a thin round cable providing serial communication. This is a newer technology than traditional parallel connections (ribbon cables). So you must know what type of drive each DVR requires.
SDK : Acronym for Software Developer’s Kit. This provides enough information for a third party to develop software that will interface with your device.
Search: In CCTV context search refers to methods used to find video in a recorded database. Typical search methods are by time/date, alarm list, smart search by video movement.
Search Engines : A search engine allows you to look up items on the Internet. Examples of search engines are Google, Yahoo and Bing.
SECAM : Sequential Couleur A Memoire (sequential color with memory), the French color TV system also adopted in Russia. The basis of operation is the sequential recording of primary colors in alternate lines. The image format is 4:3, 625 lines, 50 Hz and 6-MHz video bandwidth with a total 8 MHz of video channel width.
Server : In general a Server is an unattended PC providing programs and services to work stations. The workstations are the Clients. In CCTV context the server is the device with the cameras attached (DVR, NVR). A PC using remote software is the Client.
Siamese Cable : This is a dual cable combining RG-59 video cable and an 18 gauge wire suitable for providing 12VDC or 24VAC power. This design simplifies installation of cameras. There is no need for a locally installed AC outlet at the camera location. Power is usually provided from a power distribution box at the control end.
Signal to Noise Ratio (SNR) : A measurement of the noise level in a signal expressed in dB (decibels). A higher Signal to Noise ratio provides a higher quality signal.
S.M.A.R.T. : Acronym for Self Monitoring Analysis and Reporting System. The intent is to warn against impending PC failures before they happen (drives, fans, temperature, etc.).
SMTP : Acronym for Simple Mail Transfer Protocol (refers to Internet mail).
Spot Monitor : This is a secondary monitor connected to a DVR, Multiplexer, etc. This is also called a Call Monitor. The video displayed is typically a single image. Some units provide multiple outputs.
Static IP Address : This is the name given to a manually entered IP address. In large networks IP addresses are usually automatically assigned by DHCP.
Subnet Mask : This is a 32 bit binary number used as part of IP addressing. Each octet is expressed as a number between zero and 255. The subnet mask numbers define the network number.
SVHS or Super VHS : A higher quality extension of the VHS home videotape format, featuring higher luminance and the ability to produce better copies.
S-Video : Type of video signal used in the SVHS videotape format. S-video transmits luminance and color portions separately, using multiple wires, thus avoiding the color encoding process and its inevitable loss of picture quality. This provides the video and sync signals on different wires.
SWOT : Acronym for Strengths, Weaknesses, Opportunities and Threats. This is an evaluation method that requires you to identify both the good and bad in a situation (product, idea, etc.) and with those in mind identify potential opportunities and potential threats.