标签归档:fiber optic cable

Six Practical Cabling Tips For Better Managing Data Center

data centerAs we know, badly planned or unstructured data center cabling will usually cause more delays both in our daily work and when there is a issue in data center. Though there may be many professional team or engineers that know enough knowledge to manage the cabling in data center, or many companies will hire a network cabling service to help them do better cabling, cabling practices for data center cabling are often useful for everyone who works in a data center. Whether you choose a network cabling service or do it yourself, the following six tips for data center cabling you should know.

Tip 1. Choose the best quality cable according to your budget
As we know, there are many kinds of cables and connectors, even a variety of brands or manufacturers in the market, in order to satisfy the different demands in data center. So, you can choose more than one cable even with a same price for a same application. Certainly, according to the cable and connector materials, the better materials usually cost more but it doesn’t mean that you should buy the most expensive one. The best systems are the ones that work well for you. So you just choose the best quality one according to your appliction and location environment as well as your budget.

Tip 2. Make sure your cable can handle your data volumes
If you have enough budget, you could try to use fiber optic cables for your data center cabling as possible. With a variety of benefits, such as the greater bandwidth, higher speed, lower attenuation and greater distance etc., fiber optic cables are now used widely in many data centers all over the world. Nonetheless, copper cables also play an important role in data center cabling. About copper cables, there is a tip for your cable options. Cat3 cable is not recommended to buy since it will probably not support your data needs now, unless you have another applications that will need it. Cat5, Cat5e and Cat6 cable are different in the amount of data they can carry. If you and your team are not familiar with the capabilities of these cables, you should seek the advice of your cables vendor or network cabling service who will be able to advise you on the best solution for your needs.

Tip 3. If you expect to grow, fiber cabling may be worth the upfront expense
If you handle large volumes of data or need to cross long distances, or even expect to grow, fiber cabling is your best choice. The premise is to cost more than copper cabling. But you will find the benefits of fiber cabling soon and felt rewarded.

Tip 4. Measure your spans and double check your plan
It is known that cables become susceptible to distortion when they exceed the recommended length or span. In most time, when we measure the spans or make a plan, we may forget to include the entire length of the span, including the distance between building stories and around corners or obstructions as well as the linear distance. As a result, data quality and speed suffer. Thus, we should start with a detailed plan to ensure that the project specs call for the right cable quality.

Tip 5. Leave plenty of slack
Whenever possible leave plenty of slack in the cable to allow for changes or manage in the patch panels. Do not leave so much slacks or never over tighten, unless you want a mess of your cable room or cables stressed.

Tip 6. Labeling everything as possible
When the system of your data center is down, you or your team should be able to trace any faults immediately. Each cable or each device in your data center should be clearly labeled so you can find out the roots of the problem. Actually, there is not enough time for you to test cables at random to find a fault when the system is down.

Of course, the practical cabling tips are far more than these we have mentioned. The six tips above are just the basic ones. If you have an enough budget, you could hire a professional network cabling service to help you implement your data center cabling. If not, you may master the basic knowledge first and find professional consultation for your product selections or cabling skills as possible.

Making PLBs and tethering antigens to PLBs

We describe tethering the model Ag, NIP, or a surrogate Ag, anti-lg to PLBs. The method can be generalized to attach any biotinylated or Histagged molecule to biotin-or nickel-caontaining PLBs, respectively.


                                                         Figure 1

Figure 1 System design. Shown is a generalized diagram of the TIRFM rigs components are noted beneath the figure. All optical components to the right of the Fiber Optic Cable are mounted on a metal breadboard with screws on standard post mounts. Three lasers(boxes on right) are used to provide five usable excitation lines(wavelengths in nm indicated). After reflection on a primary mirror, the argon laser lines are directed to the AOTF via a dichroic mirror(DC1). The krypton-argon lines pass through both DC1 and DC2. After reflection on a primary mirror, the 440-nm diode laser line is directed to the AOTF via DC2. Power at the 440-nm laser head is computer controlled. Control boxes are required to interface with the computer software and are depicted as black boxes. Thin black lines at the bottom of the figure indicate computer connections. The AOTF and excitation filter wheel(FW) are linked to their respective control boxes, which in turn are coupled to the PC workstation and are controlled by MetaMorph acquisition software. The selected line is directed to the laser launch(LL) lens to allow entry into the fiber optic cable. The fiber optic cable is coupled to the TIRF illuminator (TIRFIL).The TIRF angle is controlled through the software via a motorized actuator(ACT).

Excitation light source

Continuous wave lasers provide the illumination source for our TIR FM systems. Typical laser types include gas, diode-pumped, and straight diode; all can be used in combination. The lasers are mounted on an optical breadboard with their polarity and vertical beam heights matched so that they can be combined into a single-mode fiber optic cable, which carries the light to the TIRFM illuminator on the microscope as schematically illustrated in FIG.2

Mixed gas lasers provide an economic means to obtain m ultiple laser lines from a single device. Wavelength selection is accomplished using a sofware-controlled, acousto-optical tunable filter(AOTF). Because of the inadequate blocking power of the AOTF and the fact that gas lasers produce multiple usable(and unusable wavelengths, extraneous excitation light must be blocked from reaching the extremely sensitive cameras used in TIRFM with “cleanup” excitation filters. On our systems, the cleanup filters are placed in a software-controlled filter wheel(FW) on the breadboard after the AOTF to provide versatility and to avoid reflection artifacts that occur if placed in the traditional location within the dichroic beam splitter housing.) (Related products in: Fiber Optic Splitter Box)

Straight diode and diode-pumped solid-state lasers can be up to 10 times smaller in size and are a noise-and heat-free alternative relative to their gas-driven equivalents. Straight diode lasers have a longer life expectancy relative to gas lasers whose tubes must be replaced(usually at a third of the full cost) everu 2-3 years. Straight diodes can be modelated by software control, bypassing the need for an AOTF and thus can be directly linked to a fiber optic cable either at the laser head or, as in the case of our system, mirrored directly into a fiber optic coupler. It is important to note that the square beam shape of a typical diode laser usually results in an unavoidable and significant loss of power throughput at the point of fiber optic coupling. Diode-pumped lasers use a different technology to produce their monochromatic lines and their output must be modelated through an AOTF.

Benefits and Characteristics of Fiber Optic Cable

Fiber optic cable, or simply fiber, contains one or several glass or plastic fibers at its center, or core. Data is transmitted via pulsing light sent from a laser (in the case of 1- and 10-gigabit technologies) or an LED (light-emitting diode) through the central fibers. Surrounding the fibers is a layer of glass or plastic in the strands. It reflects light back to the core in patterns that vary depending on the transmission mode. This reflection allows the fiber to bend around corners without diminishing the integrity of the light-based signal. Outside the cladding, a plastic buffer protects the cladding and core. Because the buffer is opaque, it also absorbs any light that might escape. To prevent the cable from stretching, and to protect the inner core further, strands of Kevlar surround the plastic buffer. Finally, a plastic sheath covers the strands of Kevlar.

Fiber optic cable

Like twisted pair and coaxial cabling, fiber-optic cabling comes in a number of different varieties, depending on its interned use and the manufacturer. For example, fiber optic cable used to connect the facilities of large telephone and data carries may contain as many as 1000 fibers and be heavily sheathed to prevent damage from extreme environmental conditions. At the other end of the spectrum, fiber optic patch cables for use on LANs may contain only two stands of fiber and be pliable enough to wrap around your hand. Because each strands of glass in a fiber optic cable transmits in one direction only-in simplex fashion-two strands are needed for full-duplex combined side by side in conjoined jackets. You’ll find zipcords where fiber optic cable spans relatively short distances, such as connecting a sever and switch. A zipcord may come with types of connectors on its ends, as described later in this section.

Fiber optic cable provides the following benefits over copper cabling:

  • Extremely high throughput
  • Very high resistance to noise
  • Excellent security
  • Ability to carry signals for much longer distances before requiring repeaters than copper cable
  • Industry standard for high-speed networking

The most significant drawback to the use of fiber is that covering a certain distance with fiber optic cable is more expensive than using twisted pair cable. Also, fiber-optic cable requires special equipment to splice, which means that quickly repairing a fiber-optic cable in the field (given little time or resources) can be difficult. Fiber’s characteristics are summarized in the following list:

  • Throughput – Fiber is reliable in transmitting data at rates that can reach 100 gigabits(or 100,000 megabits) per second per channel. Fiber’s amazing throughput is partly due to the physics of light traveling through glass. Unlike electric pulses traveling over copper, the light experiences virtually no resistance. Therefore, light-based signals can be transmitted at faster rates and with fewer errors than electric pulses. In fact, a pure glass strand can accept up to 1 billion laser light pules per second. Its high throughput capability makes it suitable for network backbones and for serving applications that generate a great deal of traffic, such as video or audio conferencing.
  • Cost – Fiber optic cable is the most expensive transmission medium. Because of its cost, most organizations find it impractical to run fiber to every desktop. Not only is the cable itself more expensive than copper cabling, but fiber optic transmitters and connectivity equipment can cost as much as five times more than those designed for UTP networks. In addition, hiring skilled fiber cable installers costs more than hiring twisted pair cable installers. However, as technologies improved, fiber optic cables are cheaper and cheaper. (Click to find the fiber optic cable price in Fiberstore)
  • Connectors – With fiber cabling, you can use any of 10 different types of connectors. The figures below show four of the most common connector type: the SC (subscriber connector or standard connector), ST (straight tip), LC (local connector) , and MT-RJ (mechanical transfer redistered jack). Existing fiber networks might use ST or SC connectors. However, LC and MT-RJ connectors are used on the very latest fiber optic technology. LC and MT-RJ connectors are preferable to ST and SC connectors because of their smaller size, which allows for a higher density of connections at each termination point. The MT-RJ connector is unique because it contains two strands of fiber in a single ferrule, which is a short tube within a connector that encircles the fiber and keeps it properly aligned. With two strands in each ferrule, a single MT-RJ connector provides for full-duplex signaling. Linking devices that require different connectors is simple because you can purchase fiber optic cables with different connector types at each end.
  • Noise immunity – Because fiber does not conduct electrical current to transmit signals, it is unaffected by EMI. Its impressive noise resistance is one reason why fiber can span such long distances before it requires repeaters to regenerate its signal.
  • Size and scalability – Depending on the type of fiber optic cable used, segment lengths vary from 150 to 40,000 meters. This limit is due primarily to optical loss, or the degradation of light signal after it travels a certain distance away from its source (just as the light of a flashlight dims after a certain number of feet). Optical loss accrues over long distances and grows with every connection point in the fiber network. Dust or oil in a connection (for example, from people handling the fiber while splicing it) can further exacerbate optical loss. Some types of fiber-optic cable can carry signals 40 miles while others are suited for distances under a mile. The distance a cable can carry light depends partly on the light’s wavelength. It also depends on whether the cable is single mode or multi-mode.

About Fiberstore:

As one of the world’s largest supplier, Fiberstore provides the most comprehensive fiber optic cables including armored fiber optic cables, LSZH fiber optic cables, figure 8 aerial fiber optic cables, ADSS fiber optic cables, etc.

Related articles: Fiber Optic Connector Types, Market, & Installation

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