USB Problems and How To Fix Them

Unique USB Fixes to Common Problems

(blogger@L-com.com)

USB products are everywhere. From cell phones, smart phones, digital cameras, tablet computers, camcorders, and just about every other gadget uses USB connectors on it. So you are very likely to need a USB cable, adapter, or other connectivity item as a common fact of modern life.

But USB isn't perfect. 

How to Create RJ45 Ethernet Ports at Drop Points

RJ45 couplers: what is available (blogger@L-com.com)

L-com carries a lot of stuff. In fact, the L-com web site boasts over 15,000 unique product pages. But among all those varied parts, one of the most popular items fits in the palm of your hand and weighs approximately 1 oz. What is it? An Ethernet jack! Here, we're going to talk briefly about Ethernet jacks, but don't miss L-com's exclusive video on the topic!

The Physical Infrastructure of Your LAN

How to build a high performance network (blogger@L-com.com)

An Ethernet network is composed of three things: active equipment (routers, switches, AP's, servers, etc.), passive equipment (bulk cable, cable assemblies, connectors, adapters, jacks, antennas, etc.), and a framework (racks, enclosures, patch panels, cable run ladders, faceplates at the drop point, etc.). Today, I'd like to talk about the third part: the network framework.

What is L-com?

What is L-com? (blogger@L-com.com)

L-com Global Connectivity was founded in 1982 as a family-run business to supply the burgeoning connectivity industry with quality cables, connectors, adapters, and other passive signal connectivity equipment. Today, L-com is still a privately held corporation headquartered in North Andover, MA, with four locations world wide. One of those locations, in Boca Raton, FL, is HyperLink Technologies, a quality wireless manufacturer that L-com acquired in 2007 and incorporated into its overall product offering. As a whole, L-com Global Connectivity is one of the world's most comprehensive and high-quality sources for both wired and wireless connectivity products. Not only does L-com have a huge in-stock product offering, available on its L-com.com eCommerce site, but they are a premier supplier of custom built products for large scale military, aerospace, and OEM companies. Though the way we connect electronics has changed quite a bit over the years, L-com still provides its award winning customer service, free print catalog, and free technical information on its web site.

Serial Cables - Serial Data Communication

Serial Connectivity (customerservice@L-com.com)

As technology has advanced and we've needed to pass more and more data more and more quickly between devices, serial communication has become more important. Serial communication transmits data in a precise series so that minimum skewing or modulation occurs. While it isn't as fast as parallel communication in short distances, it is superior, especially in long distances and when speed isn't exactly an issue, to older standards.

In order to make sure that all manufacturers that used serial communication could connect together, the EIA/TIA created the RS-232 standard. This way, serial keyboards, joysticks, scanners, and other equipment could be connected to terminals like computers. That same standard is followed today, but affects mainly the devices being connected, not the connection itself. Two devices with RS-232 compliant ports should be able to connect with any serial cables.

The most common connector type on a serial cable is the DB-9 connector. This D-Subminiature style connector has 9 pins in a "D" shaped footprint. L-com carries a wide variety of these types of cables, including economy D-Sub cables, deluxe, and premium (double shielded) style. These are all molded and factory terminated and tested.

Coaxial Crimp Tools

Coax Crimping Tools (customerservice@L-com.com)

Coax cables are relatively easy to put together, if you have the right equipment and know what you're doing. That is because most coax connectors are "crimp style". That isn't to say all of them are, but twist-ons don't always get as great a connection, solder styles are sometimes sensitive to bending and flexing, and compression styles are just rare.

If you are going to be making a lot of coax cable assemblies, you'll need a coax crimping tool. These are fairly wrench-like in shape and design, but in the jaws of the devices there is a "hex" shaped hole. Different coax connectors require different sized hexes to properly crimp them.

When you are buying coax connectors, make sure to check with the manufacturer what the crimping dimensions are. At L-com, we usually put them on the engineering drawing, which you can freely download from our site. Once you know the crimping dimensions, make sure that you have or that you get a crimping tool with the correct sized hex die. Many crimping tools have the dies already permanently attached so you don't have to worry about losing extra pieces. But other crimp tools are more like frames for interchangeable dies, allowing you to use the same tool in multiple situations.

If you need help selecting a tool for your job, contact us at L-com and we will walk you through it!

Category Rated Modular Couplers

Modular Couplers for Phone and Ethernet (customerservice@L-com.com)

One of the great things about modular networks is that they're... well... modular! Networks in these cases are easily set up and customizable to whatever architecture you'd like to employ.

A key component of modular networks are the couplers. Most often these are designed to be panel mountable, so they can be mounted either in a wiring closet rack panel, or in a faceplate or wall plate at a workstation.

Because modular couplers have become so ubiquitous, a large variety of colors, shapes, and make-ups are now available. L-com carries a line of modular couplers called the ECF series that have a flange that can be screwed down to a panel. Apart from that, a popular style of panel-mount coupler is the keystone style. These are designed to snap-in to holes cut to the correct dimensions.

Make sure, when you source your coupler, that you get one that meets your applications. For instance, if you are going to be using shielded twisted pair cabling (STP), you should get shielded modular couplers as well. Also, a network will run at the speed of the lowest category rated component. So, if you have a Category 5e network set up, don't try to put a Category 3 coupler in it because that will slow the whole network. You can use a higher category rated coupler, such as a Cat 6 coupler, but don't go lower.

At L-com, you can get the panel dimensions from our couplers on the engineering drawings, download-able for free from the item level page of each coupler.

L-com.com Web Site Update

Updates to L-com.com (customerservice@L-com.com)


I apologize that I hadn't written a blog entry in so long, but we've been cooking up lots of events here at L-com. The L-com.com web site is now updated with all sorts of enhancements. The first that you'll notice is the image on our home page is now a rotating gif and is clickable. Clicking on the item family that you see will bring you to a page where you can browse that kind of item.

In searches, you will notice that the page numbers are listed rather than just a "next" and "previous" button, as we had before. This will let you flip through our huge connectivity product listings more easily. We've also updated the search engine on our site to be a little more intuitive.

You may notice that on the left-hand side of our pages the navigation has changed slightly. We now list "Shop By Type" above "Shop By Category", and we've included a link to Overstock and Sale Items.

The biggest changes, though, are when you place an order online. We want the process of shopping online to be as convenient as calling or faxing orders to us.

First, when you add a cable, connector, adapter, or other connectivity product to your cart, you won't be sent to the cart page and have to back up if you want to add more items. Instead, you'll get a message that your cart has been updated and you'll stay where you are until you've finished shopping. You may see the cart icon at the top of the page blink red when there's something in it just to remind you that its there.

When you check out, if you are a new user, you won't need to enter your password up front. We'll let you go through the whole process first. You will have to put in a user name and password at the end, but we won't make you re-type all your information. We'll take it from your billing address. Speaking of the billing address, if you want to copy that to the shipping, you can easily do that now, no need to manually type it in.

Is that it? No, there's lots of other little enhancements all over the site. Check it out! Explore the whole line of products, check out the free technical information, and be sure to let us know if you have suggestions or ideas! We maintain our website for you, after all, to make shopping easier for you and more convenient.

L-com Connector Chart

What do you call this connector?(customerservice@L-com.com)

Like any industry, the connectivity industry has its jargon and unique terms. Among the more frustrating is the complicated names of connector types. Do you need a BNC or an RCA? Do you have a DB15 or an HD15? What the heck is the difference between a MD6 and a PS/2?

Fortunately, one of L-com's more popular pages on its web site, www.L-com.com, is the connector chart page. This is a free page that anyone can access to see pictures of connectors next to their names. Need a closeup? Click on any of the pictures and you can get a blown-up version to compare to your own product.

The connector chart is just one of the free educational benefits to L-com's web page, which includes tips, tutorials, video tips, educational newsletters, and white papers. On top of that, you can get CAD models, engineering drawings, and more details on most of our products for free as well! So, even if you're not ready to buy connectivity products, if you have an interest in them our site is worth a visit. Check it out here: www.L-com.com.

Industrial Rated Networking Equipment

IP67 and Harsh Environment Rated Active Networking Equipment (customerservice@L-com.com)

The benefits of connectivity are everywhere, nowadays. This includes factories, controlled environments, and even the outdoors. But the equipment needed to set up and maintain a network is often sensitive to dust, water, temperatures, changes in voltage, etc. So in these situations, you need an industrial rated Ethernet device.

The most common Ethernet networking devices that need to be protected from the harsh environment are Ethernet routers and Ethernet switches. Hirschmann and GarrettCom are two manufacturers that provide excellent quality industrial rated products, though there are many on the market.

In addition to switches and routers, you may need media converters, cables, and peripheral devices like IP cameras. You may also want to consider getting a IP67 rated enclosure, or using sealing grommets to allow cables to go between harsh environments and office environments without letting the elements seep in.

If you have very specific requirements for your active device, let L-com know! We may be able to contact our many manufacturing partners and find a device that fits your needs.

Technical Support Help

L-com's Technical Support (customerservice@L-com.com)

I've worked in L-com's Tech Support for a few years now and we've seen a lot of the same questions asked over and over. For that reason, we're creating a "Frequently Asked Questions" (FAQ) section of our web site! We're adding questions as they come to us, but please help us out by letting us know your favorite questions about connectivity, signal technology, or L-com itself.

We will keep putting questions up and, soon, modify our site search so you can easily search those questions for answers. That's not to say we don't want you to call us anymore! There's no way we can put down every single question someone might ask, and, truth be told, we really like working with our customers to help them find the answers to their questions.

Did you know we have dedicated tech support reps connected to a phone queue all day long? They answer questions quickly, and if they don't know the answer right off the bat, they'll research and get back to you, usually within a day. You can also email directly to tech support at support@L-com.com, and get a response within 24 hours!

So, with our FAQ and Technical Resources online, and our live tech support resources offline, you can get all the answers you need to make an informed decision.

HDMI Cables - Emerging Video Cable Standard

HDMI Cable Assemblies and Components (customerservice@L-com.com)


With a growing number of HDMI adopters, it's looking like HDMI may emerge as the reigning king of digital video connection types, at least in the consumer electronics side of things. But it joins a huge market of video standards, including HD15 SVGA connectors, DVI connectors, S-Video (SVHS) connectors, RCA connectors for composite or component video, SCART connectors, and coax connectors like BNC or F type connectors for RF video. And the game isn't over yet, new video standards are still emerging so who knows what we will be using a year from now?

HDMI has a lot of advantages that make it preferable to other video types. It is digital, allowing the pixel-perfect video that is preferred over analog video by many a/v enthusiasts. It is small and easy to connect, and it can carry audio as well as video, a huge plus over most other video connector types. Early on, HDMI ran into the 5 meter length limitation of digital video, but improvements in cable technology have lead to longer versions of HDMI cables hitting the market.

Look for a host of new HDMI components to come out over the next year or so. HDMI cables will probably be joined by HDMI couplers, adapters, rack panels, and active equipment like HDMI extenders. As the standard gains in public acceptance, it will also make components that use the standard easier to roll out for smaller manufacturers.

Surface Mount Boxes and Wall Plates

How Do You Create Modular Ports for Your Users to Plug Into? (customerservice@L-com.com)

Undoubtedly, one of the most important technological advances of our time is the modular network. Networked together, machines throughout an office, a building, a whole country, or all over the world can all communicate. In order to make a network user friendly, it's a good idea to provide easily accessible ports or jacks where your users' machines are.

Traditionally, there are two main ways of mounting modular jacks: in a wall or in a box mounted on a surface. By far, wall plates and face plates are the most popular way to go. With them, the jacks are flush with the wall, out of the way, but still easy to get to. But in some cases there are either no walls close by, or the walls cannot have anything running inside them. In those cases, surface mount boxes provide a perfect solution.

Boxes and face plates often come separate from the jack itself, allowing you to mix and match the correct jack with the correct mounting medium. Make sure you get a plate with the proper hole size already in it so you can easily mount the jack. The most common hole size is called Keystone, and though it is not standardized it is roughly the same from company to company.

DVI Video Standard

Digital Video Interface (DVI) - What is it?

(customerservice@L-com.com)

DVI is one of the video standards for the emerging field of digital video. As you get newer televisions, HDTV boxes, video cards for PCs, and other video equipment, you may see this type of connector more and more.

The connector is shaped vaguely like a D-Sub connector, with screws on either side to hold it mounted. It has up to 24 pins in the middle, plus four pins possibly around a bar to one side. I say "up to 24 pins" and "possibly around a bar" because there are actually several types of DVI connectors possible.

Three DVI signal types

In instruction booklets that reference the DVI cables you need, you may see a letter after DVI, like this: "DVI-D". There are actually three different types of DVI: DVI-A, DVI-I, and DVI-D. The -A is for analog only, the -D is for digital only, and the -I has both analog and digital pins. How can you tell the difference? The easiest way is to look at the bar at one side of the connector. The four pins around it are for analog signals, so if you do not have those pins, the connector is a DVI-D: it only includes digital lines. If you do have pins around the bar, and most of the pins in the center (there may be a strip of pins missing in the middle. More on this in a second), you probably have a DVI-I connector. If you only have 12 of the middle pins, you probably have a DVI-A connector.

On a male connector, usually on a DVI cable, it is important to know which type it is because if you try to plug a connector into a female port that doesn't have enough holes for the pins, then some of the pins may bend, destroying the cable. On the other hand, female DVI-I connectors can accommodate both DVI-D and DVI-A connectors because they have holes for all of the pins. Most newer DVI equipment is coming with DVI-I connectors standard for that reason.

Single Link and Dual Link DVI

Single Link and Dual Link has to do with how many channels of transmission are available in a cable assembly. You can visually tell a single link male connector from a dual link by the centermost vertical strip of pins. If they are missing, then the cable is single link only. If they are there (meaning all 24 pins are present), then the cable is dual link.

Contrary to many beliefs, dual link isn't really "better", in that the picture quality is the same. Dual link is primarily for getting up to very high resolutions, usually too high for most TVs to get to. Dual link DVI can reach a resolution of 2048 x 1536 at 60 Hz Refresh Rate, sometimes called QXGA or Quad Extended Graphics Array. In most commercial cases, this isn't necessary.

Coaxial cable

What is Coaxial Cable? (customerservice@L-com.com)

Coaxial or Coax cable is so named because the signal inside the cable runs on two (co-) axies: the center conductor and the shield. This is a relatively old cabling technology that was originally developed for military use. Coax cables were found to be so durable and efficient at carrying all sorts of signal types from data, video, audio, and more, that the standard soon became commercialized. Today, coax remains a very popular cable assembly type for cable TV, antennas, high-end audio/video equipment, and security equipment.

Though there are a few standards of coax cable available on the market, L-com only really carries the "RG" styles. RG stands for radio guide, and each cable type is generally called by RG followed by a number indicating the standard number of the cable. That is sometimes followed by a letter to indicate a sub-standard, and then the letter "U" to indicate that the standard is universal. But all this doesn't help you figure out what kind of cable you need!

With coax, the application generally dictates the kind of cable. Video cables nearly always use 75 Ohm styles of cable. Data and antennas usually use 50 Ohm styles. The different styles may have different flexibilities, diameters, attenuation, jacket types, and other factors that make one cable the ideal fit.

If you have an application but don't know what cable you need, try giving us a call or emailing directly to our tech support group at support@L-com.com. You may also find our Coaxial Cabling Tutorial helpful, available free on our web site.

The holidays are drawing to a close, but L-com sales are still on!

Plenum Patch Cables (Fiber Optic and Ethernet UTP) Sell-Off (customerservice@L-com.com)

As the year ends, we took a look around our massive warehouse and noticed many boxes of custom Plenum rated cable products built for one of our customers who didn't end up needing them. Well, we don't need them either, so we've decided to sell them at incredible prices just to give us more space!

The link to the items on sale is here:

http://www.L-com.com/PlenCloseout

Among the items are a variety of multimode and singlemode fiber optic patch cables, OFNP or Plenum rated, and various colors and lengths of Cat 5e and Cat 6 rated Plenum Ethernet cables. And the prices are so low, some of them are even cheaper than our PVC cables!

Along with that, the Overstock Sale that we started a couple of weeks ago is still going on, so check that out as well.

Hope your New Years is a happy and prosperous one!

L-com closed for Christmas

L-com Connectivity Products

Hope your holiday is bright and merry! We will be closed on Monday, December 25th, in observation of the Christmas holiday. Then there is one week left to the year and to the End Of Year sale that is still going on!

Merry Christmas

PS. If you haven't gotten your 2007 L-com Calendar FREE from us, yet, call your inside sales rep and ask them to send you one!

IEEE-1394 cable assemblies (also known as FireWire)

Firewire cables and technology (customerservice@L-com.com)

Firewire is an interface type that's been growing in popularity. Like USB, it is usually used to connect peripheral devices to computers, but it is also sometimes used to connect peripheral devices together with no computer in between. Because IEEE-1394 isn't asynchronous like USB is, you don't need a processor to manage the signals.

Does that mean that Firewire is "better" than USB? Not really, it's just different. Really, USB is far more popular right now, and maybe for that reason Firewire is often confused with USB.

Here in L-com's tech support department, we sometimes get the question, : "How do I convert USB to Firewire." But unfortunately, we don't know any easy way to do that. The problem is that USB is very different from Firewire, like two different languages. The cost to design a device that would convert one media to another is more expensive than the cost to just buy a Firewire PCI card and put it in your computer. So, if you have Firewire devices that you need to plug into a computer with only USB ports, you should probably consider getting a Firewire card to give you the proper ports.

There's been a lot of talk recently about the new Firewire 800 or IEEE-1394b standard and products for it. Right now, we're carrying an assortment of cable assemblies to meet the standard, and as demand grows we will add more products to support 800Mbps devices.

L-com's End of Year 2006 Sale!

HAPPY HOLIDAYS (customerservice@L-com.com)

Happy holidays to our blog readers and L-com customers! As a token of appreciation, our sales reps sent out the below email on Wednesday:

Hi,

Happy Holidays and thank you for being an L-com customer! 2006 was a very successful year for me here at L-com, and I’m hoping it was a good year for you too.

Because I appreciate your business, I want to make sure you know about a special End Of Year Sale going on here. I picked a couple of items I thought might interest you, but if you want to see a complete list of many more items click here.

You can’t access this special sale list from our home page, so I’m sending you the link specifically by email. Copy and paste it into your browser:

http://www.L-com.com/2006EOYsale

If you want to discuss your projects or connectivity needs, please give me a call or send me an email! I look forward to working with you in the year to come. Have a happy and prosperous New Year!

Thanks,

L-com Sales Department

TRD855BL-7 $0.99 69% Off Regular Price!

DGBH15F $3.25 60% Off Regular Price!

CC58C-5 $4.00 53% Off Regular Price!

I want to extend the same invitation to our blog readers! If there is anything we can do for you, let us know!

What is GPIB (IEEE-488)?

L-com explains IEEE 488, also known as GPIB or HPIB (customerservice@L-com.com)

GPIB stands for General Purpose Interface Bus and is really a connectivity standard, known mostly by its IEEE file number: 488. Originally, this was a great way to connect machines because you could "daisy-chain" multiple GPIB cables together.

Nowadays, GPIB isn't used as much. However, there are still a lot of machines already in use, some of them very expensive or difficult to replace, that use the IEEE-488 interface. For that reason, GPIB cables, connectors, adapters, and other products are still in demand to keep these machines connected.

The IEEE-488 standard uses a "CN24" type connector, sometimes also called a Centronics 24, or a micro-miniature 24 pin connector. It has 24 pins arranged around a rectangular opening.

Most cables with this connector have both male and female interfaces at each end of the cable. This is how you can daisy-chain the cables together: by plugging the male end of the connector into a machine, you leave the female end exposed so you can plug another male cable into it. Usually the female side is in the same orientation as the male, called "normal orientation", but in cases where you want to daisy-chain in a straight line, it is usually best to get "reverse orientation" cables so you don't have to curve the cable up over the connector when you plug it in.

Of course, since there are so many newer bus standards, people are often looking for ways to convert GPIB to USB. L-com carries a GPIB to USB converter that can help you set up a laptop and plug it into machines that use the GPIB interface.

Because GPIB is such a rare interface nowadays, we often get questions about it, so please give us a call or send us an email if you want to learn more!