Shielded Ethernet Cable: Advantages and Disadvantages

November 18, 2013 at 9:08 AM



Cat5e Shielded Ethernet Cable- 26 AWG Stranded PVC Industrial Ethernet Patch Cords - Blue

Shielding Ethernet Data from EMI/RFI


The typical Ethernet cable has four twisted pairs terminated to the eight pins in the clipped "RJ-45" (also, more correctly known as 8p x 8c connector) at either end. The cable used is commonly called "UTP", which stands for unshielded twisted-pair.


If there is an unshielded version, there must also be a shielded version right? That is correct. Today we'll look at STP, or shielded twisted-pair


The Shielding Disadvantages


Shielding is not an automatic choice for every installation. Why? Because although shielding provides the protection that may be necessary for some environments, it also comes with some serious disadvantages.

Shielded Ethernet Cable


The first is weight. A single-shielded Ethernet cable weighs on average about 12% more than an unshielded cable, and a double-shielded Ethernet cable weighs as much as 30% more. That doesn't mean much when you have a single 4oz cable. But what if your building has dozens or maybe hundreds of individual STP cables that run on ladders over a ceiling, under a floor, or behind walls? The combined weight from these cables could be such that they actually damage the rack. 


The second disadvantage is flexibility. In permanent installs, this isn't so much of an issue, though you must be careful when pulling the cable through conduit. But in applications where the cable is attached to something moving, like a robotic arm, a swiveling camera, or tools used by manufacturing personnel, the shield can be a problem. A single foil shield can break and the sharp edges of the cut in the shield would grind against the insulation of the individual wires, eventually cutting into it and shorting it out. Your best bet is to get tight-extruded cables rated for continuous flexing to ensure the maximum lifespan over repeated cycling.


Shielding Options


There are several options available if you need a shielded cable for your Ethernet application:



DisplayPort Connectivity Primer: What You Need To Know

October 20, 2013 at 8:45 AM


You may wonder why there’s a need for DisplayPort when HDMI® is as ubiquitous as it is, and with all of its capabilities above traditional analog video.


Well, DisplayPort is similar to HDMI® in a lot of ways: smaller connectors, digital video, audio/video on one cable, high definition video, 3D capabilities, etc. For most consumers, especially in the home theater market, if they plug it in and get a display on the screen then it works! And little else matters. As you'll see, however, not all audio/video applications are the same.


DisplayPort wasn't necessarily developed to improve on HDMI®, so when we compare HDMI® to DisplayPort, we're not saying it should be either/or. Instead, we're saying before you assume all the personnel in your business need HDMI®-only video cards and laptops, consider taking a look at DisplayPort's capabilities.

 Close Up View of DisplayPort Connector

HDMI® vs. DisplayPort



HDMI® is in many ways the successor to DVI, which was in many ways the bridge between analog video like VGA and digital video. Improving on DVI, HDMI® includes audio with the video in one cable, does away with the screw locks, and can provide up to 1080p HD video which is necessary for most of the latest TVs used in home theater applications. That's really what HDMI® was developed for and it does a great job.


DisplayPort was developed by VESA (Video Electronics Standards Association) as a standard for higher resolution computer display devices. It has most of the features of HDMI® plus some capabilities that are important for the high-graphic demands of some business applications.

Among the top benefits of DisplayPort are:


1. Unlike HDMI®, which does not support a very good refresh rate at the higher resolutions, DisplayPort maxes out at 3840 x 2160 pixels with a refresh rate of 60Hz, allowing it to handle very demanding video and 3D applications.

2. The DisplayPort standard can support multiple monitors (up to 4) with a single card, each receiving independent audio/video streams. This is important for individuals working on high resolution graphics, but needing more than one screen to handle the different tool bars or multiple applications running at the same time. In some cases, monitors may be "daisy chained" together, simplifying the setup.

3. DisplayPort has some other minor benefits such as longer cable lengths and a latching feature that makes them more secure in vibration applications than HDMI®'s friction fit connectors.Engineering Drawing of a DisplayPort Connector Calling Out Latches

4. Though DisplayPort is nowhere near as common as HDMI® for peripherals, that is changing. For instance, Thunderbolt, the standard developed by Intel based on the DisplayPort standard, is present on nearly all of Apple's MacBooks and other laptops and computers. Manufacturers of peripherals to be used on MacBooks and elsewhere are designing in either Thunderbolt or Mini DisplayPort to comply.


HDMI® isn't going away. Nor should it! It works great for the vast majority of applications. However, there are several applications that will benefit from DisplayPort. In time the technology for DisplayPort will probably be as relevant for those applications as HDMI® is for home theater.



Posted in: Wired

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How to Extend the Range of Your Wireless Signal

September 4, 2013 at 10:00 AM



One of the most common questions we are asked is: "How do I extend my WiFi signal?" Whether you need extension for an indoor or outdoor application, here are your options:


Use a higher gain antenna: By using a higher gain antenna you can extend your wireless signal range, though one thing to consider when using a higher gain antenna is potential loss of vertical signal coverage. Typically when you increase the gain on an antenna the RF gain pattern becomes more focused and produces a narrower horizontal beam. Read more about this phenomenon of higher gain causing less vertical signal coverage.


Add a WiFi amplifier: By adding a WiFi amplifier you can boost your wireless signal. We suggest trying one of our WiFi booster kits that are available for purchase by anyone in the United States without the need for a special FCC license. These kits offer easy set up and strong signal extension and coverage capabilities. Additionally we offer RF amplifiers for export, military and FCC licensed users supporting frequencies ranging from 900 MHz to 5.8 GHz.


Upgrade from 802.11b/g to 802.11n: If you are currently using 802.11b or 802.11g access points and wireless adapters, consider upgrading to the latest IEEE standard, 802.11n. 802.11n offers better range and speed than 802.11b and 802.11g standards products.


Use a higher power Access Point: A typical WiFi router or Access Point provides about 30mW of transmit power. By upgrading to a higher power access point or router you can boost your wireless signal resulting in extended coverage.


As with any wireless installation, Line of Sight and the Fresnel Zone must be considered along with other factors such as multipath interference. These phenomena and your physical environment (obstacles, obstructions etc.) all affect your signal strength and range.


WiFi Antennas WiFi Amplifiers WiFi Access Points
WiFi Antennas WiFi Amplifiers WiFi Access Points


By using one or a combination of these aforementioned upgrades and additions you can provide greater wireless signal coverage. Good luck!


Understanding Copper/Fiber Media Converters

August 28, 2013 at 10:00 AM

What is a Media Converter?


Diagram of fiber optic premise wiring converted to copper with media converters

A media converter is used to extend Cat 5e/6 Ethernet cabling to distances beyond the 100 meter maximum for Ethernet by converting IP voice/video/data signals to fiber optic cabling.


Where are Media Converters used?


Media converters are used in environments where EMI/RFI is present, such as manufacturing facilities and other industrial environments. Other applications include campus networks where many buildings need to be connected via fiber. Also, high-rise buildings typically use a fiber backbone, which is laid vertically and taps into copper (UTP) networks on each floor via a media converter.


L-com's Media Converter offering


L-com offers media converters designed for both commercial and industrial use.


Commercial-grade fiber-to-copper media converters from L-com


L-com Ethernet Media Converter 10/100TX to 100FX MM SC 2km

- Plug-and-play installation
- Rugged metal case ensure longevity
- Multimode and Single-mode versions available
- Easy-to-read LEDs provide at-a-glance system status information
- Operating temp: 0°C to +70°C 


Industrial DIN Rail Media Converters from L-com


LCMC Media Converters

- 35mm DIN rail mounting
- Rugged aluminum case
- 24V DC power input
- Plug and play
- Operating temp: -40°C to +70°C


Access Point (AP) Antenna Replacements

August 21, 2013 at 10:00 AM


Upgrading the antennas on your WiFi access point: How to determine the correct AP connector


Our technical support department often answers questions like: "How do I upgrade my access points' antennas?" or "How do I identify the type of connector on my WiFi access point or router?" There are a few simple steps to adding or replacing the antenna on your wireless product.


First you must check to see if the antennas on your access point are removable.


                               Front of an EnGenius wireless access point (AP) showing antennas behindBack of an EnGenius wireless access point (AP) showing antennas

Front and back of a WiFi Access Point showing removable rubber duck antennas installed


Back of an EnGenius wireless access point (AP) showing antennas removed

Back of a WiFi Access Point showing rubber duck antennas removed.


Next you should identify the type of connector the antenna jack is on the access point. One tip is to check with the manufacturer's website or user manual for your specific make and model listing for the antenna connector type. If you cannot find it on the manufacturer's web site, you can compare it with our common RF connector chart shown below.


Common RF Coaxial Connectors


Also, you may want to upgrade to a higher gain rubber duck antenna on your access point to increase the signal range and strength. View our 2.4 GHz Rubber Duck antenna selection.


Or you might want to connect your access point to an outside antenna. In this case you will need to connect a low loss coax pigtail cable to your access point and then to a longer antenna feeder cable to reach the outside antenna as illustrated below.


Illustration of low loss coax pigtail used to connect wireless AP to an antenna

Quick tip: If you need a new antenna, try L-com's Antenna Product Wizard to make your search easier. The wizard will walk you through three steps to identify antennas that match your criteria.

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