As the name implies, optical transceivers are terminal devices for optical signal transmission. Due to the substantial price reduction of optical fiber and its wide range of applications in various fields, the use of optical transceivers is increasing, and manufacturers of optical transceivers have mushroomed. However, because some of these technologies are relatively mature when the optical transceiver market is still very small, the development of new technologies requires a lot of manpower and material resources. Therefore, most of the manufacturers of optical transceivers are mainly small and medium-sized enterprises. Various brands are emerging one after another, but the quality is very different. The optical transceivers of some well-known foreign brands (such as IFS, fiber, options, etc.) have entered the Chinese market with their good performance and have become the designated brands of some large projects. However, their expensive prices make it unacceptable to some users. Some domestic companies in this environment Influential manufacturers of optical transceivers have begun to shift their products to digital optical transceivers, in order to not lose their performance to foreign brands, and the price will allow users to accept it. These domestic enterprises start from their own, from the quality of the practice to let the optical transceiver market become more standardized, but also to allow people from the new domestic brands have a new understanding.
In the long-distance optical fiber transmission, the optical fiber cable has little influence on the signal transmission. The transmission quality of the optical fiber transmission system mainly depends on the quality of the optical transceiver. Because the optical transceiver is responsible for the photoelectric conversion and the optical transmission and the optical reception, its advantages and disadvantages directly affect the entire system. Many new users or interested users need to understand the performance and application of optical transceivers to better configure and purchase.
The application of Optical Multiplexer is classified according to the current application of Optical Multiplexer:
1. Optical monitor for monitoring: It is used to transmit video signals (such as ordinary video camera output is a video signal), and can simultaneously transmit audio, control data, digital signals and Ethernet signals, mainly used in highways, urban transport, community security and Need to monitor all areas;
2. Radio and television optical transceivers: used to transmit RF signals, its end-to-end point-to-point transmission, it is directly branched in the optical path, from a transmitter to multiple receivers, mainly used in the field of optical cable transmission;
3. Telecommunications Optical Transceivers: Each basic channel of its terminal is 2M, also commonly known as 2M. Each 2M channel can transmit 30 telephone lines or transmit 2M bandwidth network signals. It is only a fixed-bandwidth channel, and its use mainly depends on and The supporting equipment connected to the optical transceiver is G. The 703 protocol is mainly applied to the fixed bandwidth telecommunications optical communications field.
Based on the different applications of these fields, the optical transceivers used by radio and television and telecommunications are relatively fixed and have fewer varieties. This is not detailed here. This chapter mainly introduces the configuration of optical transceivers used in the surveillance field.
The configuration of the optical transceiver is mainly determined according to the design and actual needs of the project. The signals transmitted by the optical transceiver are video, audio, and control signals. Therefore, the configuration is also based on these aspects.
The main technical indicators of the video index video include: input/output level, impedance, signal-to-noise ratio, bandwidth, differential gain, and differential phase. Input/output levels, impedance, and bandwidth are all standard in the monitoring area. Video input and output: 1VP-P, impedance: 75Ω, bandwidth: 10Hz-10MHz (except special application requirements). The main indicators that affect the performance of the optical transceiver in the video part are:
· Signal to Noise Ratio (S/N): The ratio of signal to noise. The higher this value, the better. Intuitively, the image has snowflake and fluttering interference patterns, and regular fine twill patterns are all low in signal to noise ratio. , In the signal to noise ratio digital optical transceiver can generally reach 67dB, while the analog optical transceiver generally does not exceed 60dB;
Differential gain (DG): The index mainly affects the saturation of the color signal. The DG distortion of the video signal means that the gain characteristic of the system changes with the level of the input signal. In general, since the luminance blanking level changes to the white level, a change occurs in the amplitude of the chroma signal at the output end of the video channel, so that in the bright part and the dark part, the color saturation, hue (especially saturation Degrees) have different changes. The digital optical transceiver DG ≤ 1%, and the analog optical transceiver DG ≤ 3%;
Differential phase (DP): its index mainly affects the hue of the color signal. The DP distortion of the video signal means that the phase shift characteristic of the system changes with the input video signal. The amount of phase shift on the transmission line varies with different luminance levels, and the phase shift between the color burst and the color subcarriers changes, so that the hue of the bright part and the dark part of the picture differ. The digital optical transmitter DP≤0.70, and the analog optical transmitter DP≤30;
· Number of coded bits (only in digital optical transceivers): Generally 8/10/12bit, the higher the number of bits, the greater the sample size, the better the image quality, but the amount of data traffic will also increase significantly. Transmission media bandwidth requirements are more stringent.
Selecting the optical transceiver from the video aspect mainly evaluates the quality of the optical transceiver according to these indicators, and then selects according to the number of ways, such as: 1, 2, 4, 8, 16, 32 and the like.
The indicators of audio performance that affect the performance of the optical transceiver in the audio part include bandwidth, impedance, input and output levels, maximum output power, signal-to-noise ratio, and nonlinear distortion. However, due to the relatively inconsistent application of audio, such as: probes (pickers) arranged at monitoring points, background music in parks, or intercoms between the two places, their requirements for audio transmission are all different. Should be considered as appropriate according to the actual situation.
In addition to the number of channels, the audio selection also divides one-way audio and two-way audio according to actual needs. Where one-way audio is applied, such as transmitting the signal of the pickup in the monitoring alarm, it only transmits the audio signal from the front end to the control center and applies bi-directional audio. Places such as audio toll stations and other places.
The selection of control data parameters to control data transmission shall take into account the use of the data, ie the communication equipment at both ends of the system, such as the matrix, hard disk recorder or other control host and the front end terminal equipment. The parameters of the data are:
Data interface: RS232, RS422, RS485 and TTL;
Data format: Manchester, Bi-phase, two-phase system;
Data rate: 1200/2400/4800/9600/11520;
Work mode: single, half duplex or full duplex.
According to these parameters, select or customize the type and quantity of optical transceiver data interfaces.
According to the above, and combined with the actual situation, determine the number of various signals, consider whether to reuse, you can come to each information point to use which or what kind of models of optical transceivers, the number of optical transceivers, optical transceivers accounted for The number of fiber cores makes the system configuration more reasonable and cost-effective.
In the long-distance optical fiber transmission, the optical fiber cable has little influence on the signal transmission. The transmission quality of the optical fiber transmission system mainly depends on the quality of the optical transceiver. Because the optical transceiver is responsible for the photoelectric conversion and the optical transmission and the optical reception, its advantages and disadvantages directly affect the entire system. Many new users or interested users need to understand the performance and application of optical transceivers to better configure and purchase.
The application of Optical Multiplexer is classified according to the current application of Optical Multiplexer:
1. Optical monitor for monitoring: It is used to transmit video signals (such as ordinary video camera output is a video signal), and can simultaneously transmit audio, control data, digital signals and Ethernet signals, mainly used in highways, urban transport, community security and Need to monitor all areas;
2. Radio and television optical transceivers: used to transmit RF signals, its end-to-end point-to-point transmission, it is directly branched in the optical path, from a transmitter to multiple receivers, mainly used in the field of optical cable transmission;
3. Telecommunications Optical Transceivers: Each basic channel of its terminal is 2M, also commonly known as 2M. Each 2M channel can transmit 30 telephone lines or transmit 2M bandwidth network signals. It is only a fixed-bandwidth channel, and its use mainly depends on and The supporting equipment connected to the optical transceiver is G. The 703 protocol is mainly applied to the fixed bandwidth telecommunications optical communications field.
Based on the different applications of these fields, the optical transceivers used by radio and television and telecommunications are relatively fixed and have fewer varieties. This is not detailed here. This chapter mainly introduces the configuration of optical transceivers used in the surveillance field.
The configuration of the optical transceiver is mainly determined according to the design and actual needs of the project. The signals transmitted by the optical transceiver are video, audio, and control signals. Therefore, the configuration is also based on these aspects.
The main technical indicators of the video index video include: input/output level, impedance, signal-to-noise ratio, bandwidth, differential gain, and differential phase. Input/output levels, impedance, and bandwidth are all standard in the monitoring area. Video input and output: 1VP-P, impedance: 75Ω, bandwidth: 10Hz-10MHz (except special application requirements). The main indicators that affect the performance of the optical transceiver in the video part are:
· Signal to Noise Ratio (S/N): The ratio of signal to noise. The higher this value, the better. Intuitively, the image has snowflake and fluttering interference patterns, and regular fine twill patterns are all low in signal to noise ratio. , In the signal to noise ratio digital optical transceiver can generally reach 67dB, while the analog optical transceiver generally does not exceed 60dB;
Differential gain (DG): The index mainly affects the saturation of the color signal. The DG distortion of the video signal means that the gain characteristic of the system changes with the level of the input signal. In general, since the luminance blanking level changes to the white level, a change occurs in the amplitude of the chroma signal at the output end of the video channel, so that in the bright part and the dark part, the color saturation, hue (especially saturation Degrees) have different changes. The digital optical transceiver DG ≤ 1%, and the analog optical transceiver DG ≤ 3%;
Differential phase (DP): its index mainly affects the hue of the color signal. The DP distortion of the video signal means that the phase shift characteristic of the system changes with the input video signal. The amount of phase shift on the transmission line varies with different luminance levels, and the phase shift between the color burst and the color subcarriers changes, so that the hue of the bright part and the dark part of the picture differ. The digital optical transmitter DP≤0.70, and the analog optical transmitter DP≤30;
· Number of coded bits (only in digital optical transceivers): Generally 8/10/12bit, the higher the number of bits, the greater the sample size, the better the image quality, but the amount of data traffic will also increase significantly. Transmission media bandwidth requirements are more stringent.
Selecting the optical transceiver from the video aspect mainly evaluates the quality of the optical transceiver according to these indicators, and then selects according to the number of ways, such as: 1, 2, 4, 8, 16, 32 and the like.
The indicators of audio performance that affect the performance of the optical transceiver in the audio part include bandwidth, impedance, input and output levels, maximum output power, signal-to-noise ratio, and nonlinear distortion. However, due to the relatively inconsistent application of audio, such as: probes (pickers) arranged at monitoring points, background music in parks, or intercoms between the two places, their requirements for audio transmission are all different. Should be considered as appropriate according to the actual situation.
In addition to the number of channels, the audio selection also divides one-way audio and two-way audio according to actual needs. Where one-way audio is applied, such as transmitting the signal of the pickup in the monitoring alarm, it only transmits the audio signal from the front end to the control center and applies bi-directional audio. Places such as audio toll stations and other places.
The selection of control data parameters to control data transmission shall take into account the use of the data, ie the communication equipment at both ends of the system, such as the matrix, hard disk recorder or other control host and the front end terminal equipment. The parameters of the data are:
Data interface: RS232, RS422, RS485 and TTL;
Data format: Manchester, Bi-phase, two-phase system;
Data rate: 1200/2400/4800/9600/11520;
Work mode: single, half duplex or full duplex.
According to these parameters, select or customize the type and quantity of optical transceiver data interfaces.
According to the above, and combined with the actual situation, determine the number of various signals, consider whether to reuse, you can come to each information point to use which or what kind of models of optical transceivers, the number of optical transceivers, optical transceivers accounted for The number of fiber cores makes the system configuration more reasonable and cost-effective.
cloth art Sofa has been loved by fashion people. A variety of cloth patterns make the cloth art sofa has a pastoral, simple, modern and other various styles of performance. The fabric art sofa of different fabrics brings us a different feeling and experience. Sofa interior structure solid wood structure -- plate wood structure -- full steel welding structure sofa filling of soft polyurethane foam (commonly known as sponge), down, artificial cotton sofa fabric hybrid fabric, chemical fiber fabric, pure cotton fabric accessories zipper, feet, hardware accessories. Sofa air permeability, sweat permeability is good, cotton and linen can absorb the sweat and micro sweat on the body skin, so that the body temperature quickly return to normal, really achieve breathable, sweat absorption effect, warm winter cool summer. Close use of comfortable, anti-itching, friendly skin. PH is acidic, has no irritation to the skin and meets environmental protection and human health requirements. Anti-static, no ball, no roll edge, cotton and linen is sewn with pure cotton, without free charge, cotton fiber is not easy to deform. Natural environmental protection, is the real green ecological textile.
Futon Bed,Pull Out Couch,Futon Couch,Chair Bed
FOSHAN CITY LESHUN RONGHUI FURNITURE CO.LTD , https://www.ronghuifurniture.com