USB Cable Length Limitations and Breakthroughs

Cable length is determined by its electrical characteristics

The cable length is determined by its electrical characteristics, such as RS232 cable length is limited to the maximum capacity of the data cable that does not exceed 2500pF. RS485 cable length is inversely proportional to its data transfer rate, which is also determined by the electrical characteristics such as capacitance and reflection.

Different USB cable length

USB1.1 stipulates that the cable length is 3 meters and USB2.0 stipulates is 5 meters. One of the reasons constraining the length of the cable is a cable delay. We know that the current almost travels by light on the cable, but it takes some time from this end to the other end. USB 1.1 defines the maximum delay time is 18 nsec, the USB2.0 stipulates 26nsec. The current speed passing through the copper wire depends on the dielectric constant of the surrounding material. Although we cannot precisely understand the argument, we can regard 65% of the speed of light as the speed of the current flowing through the ordinary cable produced by reliable usb cable manufacturer. Count down, the USB 1.1 maximum cable length is 3.51 meter, while the USB2.0 cable length is 5.07 meter.



The quality of the USB cable is more important than the length

In fact, the quality of the USB cable is more important than the length. You might find the cheaper cable has better value for money, but actually it is not the case. Although these cheap cables may work on some devices, but they can not necessarily work properly on all devices. This is because the USB specification allows the use of a variety of driver chips, the receiver chip and cable, if your computer has cheap driver chips (low speed and low power output), and just may encounter a crappy USB peripheral interface design, then the less expensive the cable may work, cheap cable may have a communication failure. This often causes driver bugs or the Windows problems.

Methods to overcome the limitations of USB cable length

Use HUB. The HUB is simply the splitter for repeaters and the USB signal and independently provides power supply. We are optimistic that the USB cable length limit is only limited to a length of cable, not the total length of the cable between the computer and peripherals. If you are using a HUB from professional custom cable manufacturer, the maximum length between the computer and peripherals will reach 10 meters that is the host is HUB5 meters, and HUB to the peripheral is 5 meters. USB standard stipulates, HUB allows cascading 5. If you are using a 5 m cable, the maximum distance between the host and peripherals is 30 meters, without the need for any irregularities. In such case, the Ethernet and wireless data connection will be simpler than this (5 HUBs, 6 cables).

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Development Trend of China's Wire and Cable Industry

China's Wire and Cable Industry Maintain Rapid Development

To improve the situation that power grid construction in China has long lagged behind the development of the power construction in recent years, China has gradually increased investment on the grid as soon as possible to improve the power grid construction. Grid investment in China in 2008 reached 2,884.56 billion yuan, with a year-on-year growth of 17.69%, grid infrastructure investment in electricity investment proportion exceeded 50% for the first time, and the proportion of grid power investment reversed; in 2009, the online funds that electrical cable manufacturers in China invested in electric has reached 3,847 billion yuan, an increase of 33.39% over the previous year, the scale of investment continues to maintain a substantial growth. The next 10 years, China's power grid construction will enter the west to east, north and south, and the mutual supply and national network comprehensively promote the new stage of the greater range of optimal allocation of resources.


Smart Grid Construction will be the Direction of Future Investment

Premier Wen Jiabao in the March 5, 2010 put up clearly in the Government Work Report that to positively develop new energy and renewable energy and to strengthen the construction of smart grid. State Grid Corporation pointed out that the overall objective of building a smart grid: the construction of UHV power grid as the backbone and coordinated development of power at all levels to the 2010 No. 1 "to accelerate the building of strong and smart grid" information technology, automation, interactive features into a strong national grid, all improve the grid's security, economy, adaptability and interactivity. All usb cable manufacturer should work for the target as the development aim of enterprises. By 2020, China basically will built a strong and smart grid, and UHV and trans-regional transmission capacity of more than 400 million kilowatts, to meet the large-scale coal bases, large hydropower bases, large-scale nuclear power base, the 10 million-kilowatt wind power base access and load center electricity demand. Grid resource allocation capability, safety, operational efficiency, and grid power supply and user interaction are significantly improved.

Wire and Cable Industry Development Gist

At present, the development of the industry situation is grim, product homogeneity is serious, vicious competition in the industry is extremely bad. The year 2012 is an extraordinary unusual year, and enterprise development is not only the "quantity" enhancement, but also the "stable" breakthrough. Entrepreneurs should keep a clear head, not to pursue the accumulation of "quantity", "to do less is not matter, and the collection of accounts receivable in a timely manner to ensure that the enterprise funds to the normal flow of operation is the first thrust of the enterprise development this year.
This article is come from: http://cell.battery-products.com/electronic-products/development-trend- of-chinas-wire-and-cable-industry.htm