Started with a goofy animated GIF made back in August. It took a few weeks to build the sculpture using slabs of rolled out clay. Fired ‘em up, set ‘em up, and took video at the gallery. Finally edited clips together into a movie. Ya’d think I knew what the hell I was doin’… wouldn’t ya?
Archive for June, 2010
Myspace Default Sculpture – In Your Extended Network
Wednesday, June 30th, 2010Protecting your KVM and Video Extenders from Electromagnetic Noise
Saturday, June 26th, 2010KVM (keyboard, video and mouse) via CAT5 extenders can be used to remove computers from harsh environments or sensitive, or to restrict physical access to your computer. Extended Video products such as VGA, DVI, S-Video or HDTV via CAT5 extenders are used to extend the video screens. Each extension consists of two units – local and remote units, which are interconnected by a cable CAT5/5e/6. The low cost and ease of installation of twisted pair cables, such as, cat5, cat5e or CAT6 cable, made them a popular choice over traditional coaxial cable for transmission of KVM and AV signals. However, using a type of twisted-pair cable that is not appropriate for your installation environment can lead to irregular performance of the mouse or keyboard, data loss and degradation of image quality, effectively undermine the purpose your workstation or video extension. One of the causes of the video signal and loss of quality when using a twisted pair infrastructure is an installation environment with extreme electromagnetic interference (EMI or also known as radio frequency interference or RFI.)
Electromagnetic interference
Electromagnetic interference is an unwanted disturbance in an electrical circuit by electromagnetic radiation from an external source. All electrical equipment produces electromagnetic radiation during operation. The current flowing in a circuit generates a magnetic field. The potential difference or voltage required for current flow produces an electric field. Strong electric and magnetic fields can cause an electrical device to affect another. When this is not intentional, is known as electromagnetic interference, commonly abbreviated as EMI. electromagnetic interference can disrupt normal operation of electronic equipment. normal levels of EMI such as those generated by computer, switch or router will not affect NTI KVM and video extenders. However, the extreme levels of EMI on the environment can interfere with signal transmission. This can lead to distortion and loss of video image. The longer the cable, and focus less attention to the installation of cables, the more likely the effect of EMI. Some common sources of EMI are in a large building air conditioners, elevator motors, generators, radio transmitters and welders. Installing the cables near large power transformers or near (less than one foot) fluorescent lamps can also cause problems with EMI.
As EMI affect video signals
EMI affects both audio and video signals. In audio signals, environmental information obscure low-level details. In video signals, interference and signal distortion manifests itself in different ways. Figure 1 shows an image without any interference. Figure 2 shows a waveform of the video signal without interference.
Figure 1: Normal File – No interference
Figure 2: Representation of a video signal without interference
The noise from sources such as air conditioners, elevator motors, generators etc. manifests itself as spots or lines of noise, as shown in Figure 3. This is caused by electric and magnetic fields generated in the engine. The bigger engine, bigger and electric field and magnetic fields. Stop the engine and quickly, can cause interference. Figure 4 shows a waveform of the video signal with the interference of a motor.
Figure three: Interference caused by a motor
Figure 4: Representation of interference from the video signal of an engine
Torn and distorted image as shown in Figure 5 is caused by running the cables near sources of strong magnetic fields, such as large power transformers and fluorescent lights. The wires should be close (less than 1 foot) from the fluorescent lights interference. Figure 6 shows a waveform of the video signal is affected by a strong magnetic field.
Figure 5: The interference from fluorescent lights
Figure 6: Representation of interference from the video signal of a magnetic field
A visible pattern of interference lines, as shown in Figure 7 is the result of interference sources such as radio transmitters. The radio signal must be strong and close to allow it to interfere with the video signal is transmitted over a twisted pair. Figure 8 shows a waveform of the video signal with the interference of radio transmitter.
Figure 7: the interference of a radio station
Figure 8: Performance of a video signal transmitter with radio interference
Protect video signals EMI
A simple, convenient to prevent EMI from interfering with the signal transmission is to use a shielded cable to transmit the signal. Shielded cables are offered in a wide range of designs. Any type of shielded cable construction offers distinct advantages that should be considered carefully when choosing the best and most cost efficient option for a particular application. Braid Shield: Shield in a braid twisted pair, as shown in Figure 9, provides effective protection solutions in audio and RF ranges. It also provides excellent structural integrity, while maintaining good flexibility. Braid shields are better than aluminum to minimize low-frequency interference and have lower resistance of the DC.
Figure 9: Braid shielded twisted pair cable
Foil Shields, a shield of twisted pair, shown in Figure 10, provides excellent protection against electromagnetic interference and radio frequency audio. Weigh and cost less than braided shields.
Figure 10: Shielded Foil Twisted Pair
Due to its small size, the aluminum shields are commonly used to protect the individual wire pairs from several pairs to reduce crosstalk. Drain wires are usually used with the blade shield termination facility for connecting the socket. Combination Foil / Braid Shields: A screen twisted pair combination paper / braid, shown in Figure 11, provides the most effective shield over the entire frequency spectrum. The role of the combination / braid combines the benefits of a coverage of 100 percent aluminum with strength and low DC resistance of a braid.
Figure 11: Foil and braid screened cable pair Twist
How to help reduce the problems of protection against EMI
Reflection and absorption are the main ways in which significantly reduces EMI shielding strength of signal carrying conductors in a twisted pair shielded. Figure 12 is a representation of how the cable may reflect the high frequency EMI, as a radio transmitter. The shield itself also absorb the energy of a radio transmitter EMI, reducing the amount of EMI that makes the inner loop conductors. When properly installed with shielded connectors with ground equipment, shielding redirects a small amount of electromagnetic energy. These effects of reflection, absorption and redirection of protecting highly effective in reducing the problems of high frequency interference.
Figure 12: Representation of Braid or reflective aluminum with EMI shielding
The best way to protect against EMI from low frequency magnetic fields as a large motor or transformer, is to provide sufficient distance between the cable and the source of the field of interference. Cable shielding has only a limited effect to avoid interference problems of low frequency magnetic fields. Instead of a magnetic field to reduce the reflection or absorption, the cable produces a magnetic field instead of reducing the interference of magnetic field frequency. This is the result of the reduction of the variable magnetic field intensity that reaches the pair of conductors. Figure 13 is a representation of how screening can reduce the strength of this type of interference to reach inner conductors twisted pair.
Figure 13: Cable shield reduces the intensity EMI on cable
The statement
If you have a problem of electromagnetic noise, we recommend using shielded cable. When it comes to higher frequency electromagnetic noise only, like a radio transmitter, a length of shielded cable to provide adequate protection. For effective protection against low frequency electromagnetic fields, such as an electric motor, a braided shield or a combination of paper / woven screen is mandatory. If you are unsure about the type of electromagnetic noise, you should use a combination of aluminum / braid shielded cable, as it provides the best protection against a wide variety of electromagnetic disturbances.
Networking Hardware You Need In Your Organization
Sunday, June 6th, 2010No matter if it is associated with the government or education, you will gain an important tool to perform their functions best. For example, there are many areas where things can not happen without the kind of printer and scanner. That’s where people think getting a network printer HP Scanjet N7710. However, when it comes to networking, there are a variety of hardware that should be in place. This is one reason for the enormous importance of finding the right place is immense. In fact, there are many devices and apparatus for use in an organization and that the sale of a network hardware site gives a hand. But do you really know what kind of network hardware is important to you? Here are some popular choices for you to consider. • Ask any person on a major network hardware and “network camera” is the answer. Without using the right type of network camera can not handle many different tasks. But, when buying a camcorder, you should pay attention specific characteristics. Always make sure the camera is equipped with features like digital zoom with presets, full screen control, integrated microphone, remote control from your phone, Plug and Play installation, and date and brand image time. • Another important thing is extremely important for all organizations involved in the network has a firewall. It is very important to pay attention to this particular aspect. Fortunately, now you can find some options in that regard. There are places selling network security and firewalls, to help keep out intruders from entering your network. But be sure to buy this particular network hardware after paying attention to their characteristics. When you buy one, you should be sure to get the maximum functionality and overall customer VPN, certification of compliance Verde, 10 or more ports, 128 MB or more memory and speed of 30Mbps encryption. • routers and gateways are also important for the network. They offer many benefits, but if you are interested in getting the maximum benefit you should opt for integrated services routers. Comes with 2 ports, 10 Mbps data transfer, intrusion prevention, Network Admission Control, control of four interface slots for expansion cards, and 256 MB of DRAM. • In addition to these types of network hardware, there are some others that should be in your organization. For example, PoE injectors and splitters, consoles and loads, print server and network interface modules,, USB hubs , host bus adapters and network cards are some popular network hardware options. Therefore, these options are very popular for those who do not know much about networking hardware. all this is necessary and you should find a place better. Simply connect to the internet and start searching for the best place to make a purchase.
Wireless Networking Components
Wednesday, June 2nd, 2010Client Software and adapter
Any client computer, laptop or mobile device with a compatible wireless client adapter allows connectivity to an access point. The client adapter is a radio transmitter with the firmware compatible with any of the 802. 11a/b/g alert. What is necessary for the device can associate and authenticate with the access point. Some access points do not have a client mode that does not allow any association by customers to extend the distance of the network. The wireless client software included with the card must be carried out with specific Windows platforms. The client adapter will be integrated with the laptop, desktop or PCMCIA slot of the PCI bus. Will support specific wireless standards, characteristics of the antenna, Wi-Fi certification, WDS, scope and network security. The maker of wireless software to be used for all functions. Below is a list of some client adapters configured settings.
Access Point
As its name suggests an access point connectivity between the wireless client or wireless device and the wired network. The wireless access point takes data packets from a client and translates them into standard Ethernet frames before transmission of data over the wired network. standard category 5 twisted pair cabling will connect the access point Ethernet ports with an Ethernet port Catalyst. The maximum distance between access point and network switch is 100 meters with a standard design of Ethernet.
WLAN Controller
designs with hundreds of wireless access points due to a corporate network, sometimes deploying wireless LAN controllers. The specially designed lightweight access points that connect to a network switch. WLAN control device 4404 acts as a hub connecting four network switch to support 100 access points. Cisco Wireless Control System (WCS) management software of the wireless network is sometimes distributed controller design for WLAN planning, configuration and network optimization.
Power Injector
Cisco access points have a variety of input options, such as AC adapters, power over Ethernet and power injectors. The placement of access points is such that in some situations, an AC outlet is not available. If the Ethernet switch does not support Power over Ethernet power injectors an option, as it extends away from an AC outlet. Distances of 1. 24 miles converters are available with a fiber optic media.
Power over Ethernet
Cisco access points can be implemented with Power over Ethernet (PoE), where the network switch modules support this feature. The 300 meters is the same with Cisco pre-standard and 802. 3AF. Using Cisco pre-standard Category 5 wiring pins 1, 2, 3, 6 for power devices, and 802. 3AF uses 1, 2, 3 and 6 with 10/100/1000BaseT signaling 4, 5, 7, 8 with 10/100BaseT. Select a module network switches with power over the common access point Ethernet has been implemented and an evaluation of output power per port for specific devices. The power switch of the power system must be updated to support more power consumption from multiple devices. Distribution of power over Ethernet reduce implementation costs, with the distribution of IPT, wireless and Gigabit. See documents on the network switches from Cisco website for information on what network switch modules support PoE, and power. 802. 3AF powered device class set 2-3. 84W – 6. 49W and class 3-6. 49W – 12. 95W.
Power Patch Panel
Cisco Inline Power Panels can be implemented as Ethernet switches do not support power over Ethernet power injectors are not an option. The connection panel is not active. Turn on the computer via a CAT 5 cable is a maximum of 300 meters at a specific power for each port. The patch panel connects the access point to switch wiring with a cable.
Cisco Wireless Network Design Guide, available on Amazon. eBookMall y. com com
Shaun Hummel is an author of several technical books and a website focused on finding solutions to Information Technology jobs and certification.
http://www. networkjobsolutions. com