Posted on December 27, 2011 by Meghan Damico
Driving data? Better check the transmission.
Line drivers can operate in any of four transmission modes: 4-wire full-duplex, 2-wire full-duplex, 4-wire half-duplex, and 2-wire half-duplex. In fact, most models support more than one type of operation.
So how do you know which line driver to use in your application?
The deal with duplexing.
First you must decide if you need half- or full-duplex transmission. In half-duplex transmission, voice or data signals are transmitted in only one direction at a time, as in a CB radio conversation. In full-duplex operation, voice or data signals are transmitted in both directions at the same time, as in a telephone conversation.
The entire bandwidth is available for your transmission in half-duplex mode. In full-duplex mode, however, the bandwidth must be split in two because data travels in both directions simultaneously.
Two wires or not two wires? That is the question.
The second consideration you have is the type of twisted-pair cable you need to complete your data transmissions. Generally you need twisted-pair cable with either two or four wires. Often the type of cabling that’s already installed in a building dictates what kind of a line driver you use. For example, if two twisted pairs of UTP cabling are available, you can use a line driver that operates in 4-wire applications, such as the Short-Haul Modem-B Async. Otherwise, you might choose a line driver that works for 2-wire applications, such as the Short-Haul Modem-B Async, 2-wire.
Filed under: ProAV | Tagged: datacom, datacommunications, line driver | Leave a comment »
Posted on December 22, 2011 by Meghan Damico
New tool alert! The Fiber Optic Association
released Version 1.0.1 of its LossCalc app
for the iPhone®
, and iPod®
. This app estimates the optical loss of a fiber optic link. This saves the installer time in determining whether or not test results are reasonable or are pass/fail. The app can also help link designers determine if communications equipment will operate over the link. This second version of the app fixes a bug in saving reports. You can download the app from iTunes®
for free. The app enables users to calculate end-to-end link loss for single-mode and multimode links based on the length of the link, number of connections, and number of splices.
What other IT related apps do you use on the job?
Filed under: IT Infrastructure | Tagged: Fiber Optic, IT apps, Optical loss | Leave a comment »
Posted on December 20, 2011 by Meghan Damico
The “parts” of a digital signage project can become a tangled web of technologies if not understood as standalone elements and then as a whole. “The 7 Key Elements of Digital Signage” provides clarity and a way to connect the dots on any and all digital signage projects. Keep in mind that every digital signage system contains all of the 7 Key Elements in one form or another and if ignored, can become the weak link in the chain.
Below are major project questions broken down into ”The 7 Key Elements of Digital Signage.” By answering each one, you increase your knowledge about the requirements of a project and you increase your probability of success.
[Click image to enlarge]
Filed under: ProAV | Tagged: 7 key elements of digital signage, Digital Signage, digital signage content, digital signage design, digital signage hardware | Leave a comment »
Posted on December 14, 2011 by Meghan Damico
Networking equipment—especially servers—generates a lot of heat in a relatively small area. Today’s servers are smaller and have faster CPUs than ever. Because most of the power used by these devices is dissipated into the air as heat, they can really strain the cooling capacity of your data center. The components housed in a medium-sized data center can easily generate enough heat to heat a house in the dead of winter!
So cool you must, because when network components become hot, they’re prone to failure and a shortened lifespan. Damage caused by heat is not always immediately evident as a catastrophic meltdown—signs of heat damage include node crashes and hardware failures that can happen over a period of weeks or even moths, leading to chronic downtime.
It’s also important to ensure that individual cabinets used for network equipment provide adequate ventilation. The temperature inside a cabinet is affected by many variables, including door perforations, cabinet size, and the types of components housed within the cabinet.
The most direct way to cool network equipment is to ensure adequate airflow. The goal is that every server, every router, every switch has the necessary amount of air no matter how high or low it is in the cabinet. It takes a certain volume of air to cool a device to within its ideal temperature range. Equipment manufacturers provide very little guidance about how to do this; however, there are some very basic methods you can use to maximize the ventilation within your cabinets.
Filed under: IT Infrastructure | Tagged: cabinet, cooling, data center, racks | Leave a comment »
Posted on December 8, 2011 by Meghan Damico
Fiber optic cable
is one of the fastest-growing transmission mediums for both new cabling installations and upgrades, including backbone, horizontal, and even desktop applications. Fiber offers a number of advantages over copper.
1. Greater bandwidth
Fiber provides far greater bandwidth than copper and has standardized performance up to 10 Gbps. While not currently a standard, these speeds could become a reality in future proposals and ratifications. Keep in mind that fiber speeds are dependent on the type of cable used. Single-mode cable offers far greater distance than either 62.5- or 50-micron multimode cable. In addition, fiber optic cable can carry more information with greater fidelity than copper wire. That’s why telephone and CATV companies are converting to fiber.
2. Low attenuation and greater distance
Because the fiber optic signal is made of light, very little signal loss occurs during transmission, and data can move at higher speeds and greater distances. Fiber does not have the 100-meter (9328-ft.) distance limitation of unshielded twisted pair copper (without a booster). Fiber distances can range from 300 meters (984.2 ft.) to 40 kilometers (24.8 mi.), depending on the style of cable, wavelength, and network. Because fiber signals need less boosting than copper ones do, the cable performs better.
Your data is safe with fiber cable. It doesn’t radiate signals and is extremely difficult to tap. If the cable is tapped, it’s very easy to monitor because the cable leaks light, causing the entire system to fail. If an attempt is made to break the physical security of your fiber system, you’ll know it.
Fiber networks also enable you to put all your electronics and hardware in one central location, instead of having wiring closets with equipment throughout the building.
Filed under: IT Infrastructure | Tagged: copper cable, fiber optic cable | 12 Comments »