Κυριακή, 13 Ιανουαρίου 2013

How to Make a Network Cable




The steps below are general Ethernet Category 5 (commonly known as Cat 5) cable construction guidelines. For our example, we will be making a Category 5e patch cable, but the same general method will work for making any category of network cables.
  1. 1
    Unroll the required length of network cable and add a little extra wire, just in case. If a boot is to be fitted, do so before stripping away the sleeve and ensure the boot faces the correct way.

    Kabeltester K40-XP

    PC-Kabeltester mit Kabeleditor schnell und einfach zu bedienen
    www.schibe.de
  2. 2
    Carefully remove the outer jacket of the cable.
    Carefully remove the outer jacket of the cable.
    Carefully remove the outer jacket of the cable. Be careful when stripping the jacket as to not nick or cut the internal wiring. One good way to do this is to cut lengthwise with snips or a knife along the side of the cable, away from yourself, about an inch toward the open end. This reduces the risk of nicking the wires' insulation. Locate the string inside with the wires, or if no string is found, use the wires themselves to unzip the sheath of the cable by holding the sheath in one hand and pulling sideways with the string or wire. Cut away the unzipped sheath and cut the twisted pairs about 1 1/4" (30 mm). You will notice 8 wires twisted in 4 pairs. Each pair will have one wire of a certain color and another wire that is white with a colored stripe matching its partner (this wire is called a tracer).
  3. 3
    Inspect the newly revealed wires for any cuts or scrapes that expose the copper wire inside.
    Inspect the newly revealed wires for any cuts or scrapes that expose the copper wire inside.
    Inspect the newly revealed wires for any cuts or scrapes that expose the copper wire inside. If you have breached the protective sheath of any wire, you will need to cut the entire segment of wires off and start over at step one. Exposed copper wire will lead to cross-talk, poor performance or no connectivity at all. It is important that the jacket for all network cables remains intact.
  4. 4
    Untwist the pairs so they will lay flat between your fingers.
    Untwist the pairs so they will lay flat between your fingers.
    Untwist the pairs so they will lay flat between your fingers. The white piece of thread can be cut off even with the jacket and disposed (see Warnings). For easier handling, cut the wires so that they are 3/4" (19 mm) long from the base of the jacket and even in length.
  5. 5
    Arrange the wires based on the wiring specifications you are following.
    Arrange the wires based on the wiring specifications you are following.
    Arrange the wires based on the wiring specifications you are following. There are two methods set by the TIA, 568A and 568B. Which one you use will depend on what is being connected. A straight-through cable is used to connect two different-layer devices (e.g. a hub and a PC). Two like devices normally require a cross-over cable. The difference between the two is that a straight-through cable has both ends wired identically with 568B, while a cross-over cable has one end wired 568A and the other end wired 568B.[1] For our demonstration in the following steps, we will use 568B, but the instructions can easily be adapted to 568A.
    • 568B - Put the wires in the following order, from left to right:

      • white orange
      • orange
      • white green
      • blue
      • white blue
      • green
      • white brown
      • brown
    • 568A - from left to right:
      • white/green
      • green
      • white/orange
      • blue
      • white/blue
      • orange
      • white/brown
      • brown
θέλουμε να εμφανίζονται μετά το "Διαβάστε περισσότερα". 
 
Read more...

HTML Codes - Free

HTML Codes - Free

Grab your free HTML codes here! Everything from basic music HTML codes, cool font codes, even free cursor codes!
You can copy/paste these codes straight into your web page, and in most cases, your MySpace page.
Also check out this HTML help!

Text Codes

Table Codes

Color Codes

Image Codes

HTML Links

Background Codes

Scroll Box Codes

Comment Box Codes

Marquee Codes

Window Codes

Music/Video Codes

Frames

Forms

More HTML Codes

MySpace Codes

Free HTML Generators

Free MySpace Generators

HTML Reference

Read more...

Σάββατο, 12 Ιανουαρίου 2013

Installing a network camera

Once a network camera has been purchased, the way it is installed is just as important.

Recommendations

To best achieve high-quality video surveillance based on camera positioning and environmental considerations, follow these recommendations:

Surveillance objective

If the aim is to get an overview of an area to be able to track the movement of people or objects, make sure a camera that is suitable for the task is placed in a position that achieves the objective. If the intention is to be able to identify a person or object, the camera must be positioned or focused in a way that will capture the level of detail needed for identification purposes. Local police authorities may also be able to provide guidelines on how best to position a camera.

Use lots of light or add light if needed

It is normally easy and cost-effective to add strong lamps in both indoor and outdoor situations to provide the necessary light conditions for capturing good images.

Avoid direct sunlight

As it will “blind” the camera and can reduce the performance of the image sensor. If possible, position the camera with the sun shining from behind the camera.

Avoid backlight

This problem typically occurs when attempting to capture an object in front of a window. To avoid this problem, reposition the camera or use curtains and close blinds if possible. If it is not possible to reposition the camera, add frontal lighting. Cameras with support for wide dynamic range are better at handling a backlight scenario.

Reduce the dynamic range of the scene

In outdoor environments, viewing too much sky results in too high a dynamic range. If the camera does not support wide dynamic range, a solution is to mount the camera high above the ground, using a pole if needed.

Adjust camera settings

It may be necessary at times to adjust settings for white balance, brightness and sharpness to obtain an optimal image. In low light situations, users must also prioritize either frame rate or image quality.

Legal considerations

Video surveillance can be restricted or prohibited by laws that vary from country to country. It is advisable to check the laws in the local region before installing a video surveillance system. It may be necessary, for instance, to register or get a license for video surveillance, particularly in public areas. Signage may be required. Video recordings may require time and date stamping. There may be rules regulating how long video should be retained. Audio recordings may or may not be permitted.
Read more...