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Archive for May, 2010

CCTV PTZ Cameras Video Transmission over Fiber Optics Application

May 27, 2010 Leave a comment

Single CCTV PTZ Camera Video Transmission over fiber optics, support 8-bit digitally encoded broadcast quality video, data and 10M/100M IP Ehternet over one multi-mode or single-mode optical fiber. The modules are directly compatible with NTSC, PAL, and SECAM camera systems and support RS-485, RS-232, and RS-422 data protocols. These Transmitter and Receiver are typically used in applications with PTZ cameras for security surveillance, CCTV, ITS, CIQ, etc.

Application:
Remote PTZ analog camera with fiber optical connection to be viewed on a video monitor.
EXAMPLE: Owner of building needs to view and control an PTZ Dome Camera from Monitor Center.

Solution:
Standard PTZ equipped CCTV camera is connected to the VOSCOM Fiber Optic Video & Data Transmitter using standard coax cable. The transmitter digitally compresses the signal for transmission across the Fiber Optical Cable.
At the Monitor Center, the receiver can receive the signal and the user can view the video image and control the camera movement using a standard Keyboard.
more information please find in the website: www.voscom.com

Notes:
1) VOSCOM Fiber Optic Transmitter can transmit 1~64 channels video signals and data support RS485, RS232, RS422. you can choose our fiber optic products according to your needs.
2) If you just need to control the PTZ cameras, one return data is enough, in theory, one channel data can control 1~128 PTZ cameras, the detail connection information you can refer to your PTZ camera’s manual.

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Fixed CCTV Cameras Video over Fiber Transmission Application

May 17, 2010 Leave a comment

Single Fixed Camera to Video Monitor Transmission over Fiber Optical Cable. The camera video transmission over fiber that delivers a sharper image with better color quantification and faster, more efficient codecs. The video over one multi-mode or single-mode optical fiber. The modules are directly compatible with NTSC, PAL, and SECAM camera systems.

Application:
Remote fixed analog camera with fiber optical connection to be viewed on a video monitor.
EXAMPLE: Apartment residents need to view the main entrance camera via the Fiber Optics.

camera video over fiber

Solution:
Standard CCTV camera is connected to VOSCOM Fiber Optic Video Transmitter using standard coax cable. The transmitter digitally compresses the signal for optical transmission across the fiber optical cable.
At the Monitor Center, the receiver can receive the signal and user can view the video image using a monitor.

Notes:
1) While this will also work for viewing a PTZ camera additional wiring is necessary in order to PTZ control the camera (see Single PTZ to Monitor).
2) VOSCOM Fiber Optic Video Transmitter and Receiver can transmit 1~64 channels video signals, you can choose our fiber optic products according to your needs.

Baseband Video Fiber Optic Transmission

May 13, 2010 Leave a comment

Baseband video consists of one video picture being sent point-to-point, such as the video output of a VCR to the video input of a monitor. Figure 1 illustrates simple point-to-point transmission. There exist two levels of service for baseband video: broadcast studio and consumer. These types describe, primarily, the quality of the signal. Broadcast studio quality requires a much higher signal fidelity, while consumer quality baseband requires is less demanding. In addition to the difference in signal fidelity, there is also a difference in the connectors typically used for the transmission of these signals. The broadcast baseband applications typically use a BNC connector and the consumer baseband applications typically uses an RCA connector.

Figure 1 – Point-to-Point Transmission

Figure 2 – BNC and RCA Connectors

Baseband Video Signals
The most basic form of a television signal is a baseband video signal, also referred to as a composite video signal. In an AM baseband system, the input signal directly modulates the strength of the transmitter output, in this case light. The baseband signal contains information relative to creating the television picture only. The following information is carried on a baseband signal:

• Scanning: drawing the television picture
• Luminance: the brightness of the picture
• Chrominance: the color of the picture

The creation of the baseband signal produces a range of frequency components. The highest frequency in a baseband signal is also its bandwidth. The lowest frequency ranges close to zero Hz or DC. The video output of a television camera or video tape recorder has its highest frequency, therefore, its bandwidth, at either 4.2 or 6 MHz, depending on the type of TV format used. Looking at an actual baseband signal, illustrated in Figure 3, we can see that the camera and the video display are scanned horizontally and vertically. The horizontal lines on the screen are scanned alternately, with the odd numbered lines first and the even numbered lines second, or vice versa. (Figure 3B depicts the initial scan of the odd numbered lines.) This method is known as an interlacing system. The second method is to scan the lines sequentially; this is known as progressive Scanning. The camera and receiver must be synchronized when scanning and reproducing an image. The horizontal and vertical sync pulses regulate the synchronization of the camera and receiver, illustrated in both 3B and 3C, and starts a horizontal trace. As seen in Figure 3A, during the horizontal blanking interval, the beam returns to the left side of the screen and waits for the horizontal sync pulse before tracing another line. The dotted line illustrated the horizontal retrace. When the beam reaches the bottom of the screen, it must return to the top to begin the next field. This is called the vertical retrace, which is signaled by the vertical sync pulse illustrated in Figure 3C. The vertical retrace takes much longer than the horizontal retrace, therefore, a vertical blanking interval ensues to synchronize the two signals. During both the horizontal or vertical blanking intervals no information appears on the screen.

Figure 3 – Baseband Composite Video Signals

Baseband Video Applications
Figure 4 illustrates a multimedia baseband fiber optic transmission systems.

Figure 4 – Multimedia baseband transmission