Loading


Categories (x) > Industrial (x)
Content Type (x) > Black Box Explains (x)

Results 31-40 of 63 < 1 2 3 4 5 > >> 

Black Box Explains...Low-profile PCI serial adapters.

Ever notice that newer computers are getting smaller and slimmer? That means regular PCI boards won’t fit into these computers’ low-profile PCI slots. But because miniaturization is the rage in... more/see it nowall matters of technology, it was only a short matter of time before low-profile PCI serial adapters became available—and Black Box has them.

Low-profile cards meet the PCI Special Interest Group (PCI-SIG) Low-Profile PCI specifications, the form-factor definitions for input/output expansion. Low-Profile PCI has two card lengths defined for 32-bit bus cards: MD1 and MD2. MD1 is the smaller of the two, with cards no larger than 4.721 inches long and 2.536 inches high. MD2 cards are a maximum of 6.6 inches long and 2.536 inches high.

BLACK BOX® Low-Profile Serial PCI cards comply with the MD1 low-profile specification and are compatible with the universal bus. Universal bus is a PCI card that can operate in either a 5-V or 3.3-V signaling level system. collapse


Black Box Explains...Solid vs. stranded cable.

Solid-conductor cable is designed for backbone and horizontal cable runs. Use it for runs between two wiring closets or from the wiring closet to a wallplate. Solid cable shouldn’t be... more/see it nowbent, flexed, or twisted repeatedly. Its attenuation is lower than that of stranded-conductor cable.

Stranded cable is for use in shorter runs between network interface cards (NICs) and wallplates or between concentrators and patch panels, hubs, and other rackmounted equipment. Stranded-conductor cable is much more flexible than solid-core cable. However, attenuation is higher in stranded-conductor cable, so the total length of stranded cable in your system should be kept to a minimum to reduce signal degradation. collapse


Black Box Explains…OM3 and OM4.

There are different categories of graded-index multimode fiber optic cable. The ISO/IEC 11801 Ed 2.1:2009 standard specifies categories OM1, OM2, and OM3. The TIA/EIA recognizes OM1, OM2, OM3, and OM4.... more/see it nowThe TIA/EIA ratified OM4 in August 2009 (TIA/EIA 492-AAAD). The IEEE ratified OM4 (802.ba) in June 2010.

OM1 specifies 62.5-micron cable and OM2 specifies 50-micron cable. These are commonly used in premises applications supporting Ethernet rates of 10 Mbps to 1 Gbps. They are also typically used with LED transmitters. OM1 and OM2 cable are not suitable though for today's higher-speed networks.

OM3 and OM4 are both laser-optimized multimode fiber (LOMMF) and were developed to accommodate faster networks such as 10, 40, and 100 Gbps. Both are designed for use with 850-nm VCSELS (vertical-cavity surface-emitting lasers) and have aqua sheaths.

OM3 specifies an 850-nm laser-optimized 50-micron cable with a effective modal bandwidth (EMB) of 2000 MHz/km. It can support 10-Gbps link distances up to 300 meters. OM4 specifies a high-bandwidth 850-nm laser-optimized 50-micron cable an effective modal bandwidth of 4700 MHz/km. It can support 10-Gbps link distances of 550 meters. 100-Gbps distances are 100 meters and 150 meters, respectively. Both rival single-mode fiber in performance while being significantly less expensive to implement.

OM1 and 2 are made with a different process than OM3 and 4. Non-laser-optimized fiber cable is made with a small defect in the core, called an index depression. LED light sources are commonly used with these cables.

OM3 and 4 are manufactured without the center defect. As networks migrated to higher speeds, VCSELS became more commonly used rather than LEDs, which have a maximum modulation rate of 622 Mbps. Because of that, LEDs can’t be turned on and off fast enough to support higher-speed applications. VCSELS provided the speed, but unfortunately when used with older OM1 and 2 cables, required mode-conditioning launch cables. Thus manufacturers changed the production process to eliminate the center defect and enable OM3 and OM4 cables to be used directly with the VCSELS. OM3/OM4 Comparison
850 nm High Performance EMB (MHz/km)

OM3: 2000

OM4: 4700


850-nm Ethernet Distance
1-GbE
OM3: 1000 m

OM4: 1000 m


10-GbE
OM3: 300 m

OM4: 550 m


40-GbE
OM3: 100 m

OM4: 150 m


100-GbE
OM3: 100 m

OM4: 150 m

collapse


Black Box Explains...How a line driver operates.

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... more/see it nowthan 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, In full-duplex operation, voice or data signals are transmitted in both directions at the same time. In both scenarios, the communications path support the full data rate.

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 or the Line Driver-Dual Handshake models. Otherwise, you might choose a line driver that works for 2-wire applications, such as the Short-Haul Modem-B 2W or the Async 2-Wire Short-Haul Modem.

If you have the capabilities to support both 2- and 4-wire operation in half- or full-duplex mode, we even offer line drivers that support all four types of operation.

As always, if you’re still unsure which operational mode will work for your particular applications, consult our Technical Support experts and they’ll help you make your decision. collapse


Black Box Explains...DIN rail usage.

DIN rail is an industry-standard metal rail, usually installed inside an electrical enclosure, which serves as a mount for small electrical devices specially designed for use with DIN rails. These... more/see it nowdevices snap right onto the rails, sometimes requiring a set screw, and are then wired together.

Many different devices are available for mounting on DIN rails: terminal blocks, interface converters, media converter switches, repeaters, surge protectors, PLCs, fuses, or power supplies, just to name a few.

DIN rails are a space-saving way to accommodate components. And because DIN rail devices are so easy to install, replace, maintain, and inspect, this is an exceptionally convenient system that has become very popular in recent years.

A standard DIN rail is 35 mm wide with raised-lip edges, its dimensions outlined by the Deutsche Institut für Normung, a German standardization body. Rails are generally available in aluminum or steel and may be cut for installation. Depending on the requirements of the mounted components, the rail may need to be grounded. collapse


Black Box Explains...How computer speeds are enhanced with PCI buses and UARTs.

The Peripheral Component Interconnect (PCI®) Bus enhances both speed and throughput. The PCI Local Bus is a high-performance bus that provides a processor-independent data path between the CPU and high-speed... more/see it nowperipherals. PCI is a robust interconnect interface designed specifically to accommodate multiple high-performance peripherals for graphics, full-motion video, SCSI, and LANs.

UARTs (Universal Asynchronous Receiver/ Transmitters) are integrated circuits that convert bytes from the computer bus into serial bits for transmission. By providing surplus memory in a buffer, UARTs help your applications overcome the factors that slow down your system. collapse


Black Box Explains...Media converters.



Media converters interconnect different cable types such as twisted pair, fiber, and coax within an existing network. They are often used to connect newer Ethernet equipment to legacy cabling.... more/see it nowThey can also be used in pairs to insert a fiber segment into copper networks to increase cabling distances and enhance immunity to electromagnetic interference (EMI).


Traditional media converters are purely Layer 1 devices that only convert electrical signals and physical media. They don’t do anything to the data coming through the link so they’re totally transparent to data. These converters have two ports—one port for each media type. Layer 1 media converters only operate at one speed and cannot, for instance, support both 10-Mbps and 100-Mbps Ethernet.


Some media converters are more advanced Layer 2 Ethernet devices that, like traditional media converters, provide Layer 1 electrical and physical conversion. But, unlike traditional media converters, they also provide Layer 2 services—in other words, they’re really switches. This kind of media converter often has more than two ports, enabling you to, for instance, extend two or more copper links across a single fiber link. They also often feature autosensing ports on the copper side, making them useful for linking segments operating at different speeds.


Media converters are available in standalone models that convert between two different media types and in chassis-based models that connect many different media types in a single housing.




Rent an apartment

Standalone converters convert between two media. But, like a small apartment, they can be outgrown. Consider your current and future applications before selecting a media converter. Standalone converters are available in many configurations, including 10BASE-T to multimode or single-mode fiber, 10BASE-T to Thin coax (ThinNet), 10BASE-T to thick coax (standard Ethernet), CDDI to FDDI, and Thin coax to fiber. 100BASE-T and 100BASE-FX models that connect UTP to single- or multimode fiber are also available. With the development of Gigabit Ethernet (1000 Mbps), media converters have been created to make the transition to high-speed networks easier.




...or buy a house.

Chassis-based or modular media converters are normally rackmountable and have slots that house media converter modules. Like a well-planned house, the chassis gives you room to grow. These are used when many Ethernet segments of different media types need to be connected in a central location. Modules are available for the same conversions performed by the standalone converters, and 10BASE-T, 100BASE-TX, 100BASE-FX, and Gigabit modules may also be mixed.

collapse


Black Box Explains...RS-232.

RS-232, also known as RS-232C and TIA/EIA-232-E, is a group of electrical, functional, and mechanical specifications for serial interfaces between computers, terminals, and peripherals. The RS-232 standard was developed by... more/see it nowthe Electrical Industries Association (EIA), and defines requirements for connecting data communications equipment (DCE)—modems, converters, etc.—and data terminal equipment (DTE)—computers, controllers, etc.) devices. RS-232 transmits data at speeds up to 115 Kbps and over distances up to 50 feet (15.2 m).

The standard, which is functionally equivalent to ITU V.24/V.28, specifies the workings of the interface, circuitry, and connector pinning. Both sync and async binary data transmission fall under RS-232. Although RS-232 is sometimes still used to transmit data from PCs to peripheral devices, the most common uses today are for network console ports and for industrial devices.

Even though RS-232 is a “standard,” you can’t necessarily expect seamless communication between two RS-232 devices. Why? Because different devices have different circuitry or pinning, and different wires may be designated to perform different functions.

The typical RS-232 connector is DB25, but some PCs and other data communication devices have DB9 connectors and many newer devices have RJ-45 RS-232 ports. To connect 9-pin PC ports or RJ-45 to devices with 25-pin connectors, you will require a simple adapter cable. collapse


The difference between unmanaged, managed, and Web-smart switches

With regard to management options, the three primary classes of switches are unmanaged, managed, and Web smart. Which you choose depends largely on the size of your network and how... more/see it nowmuch control you need over that network.

Unmanaged switches are basic plug-and-play switches with no remote configuration, management, or monitoring options, although many can be locally monitored and configured via LED indicators and DIP switches. These inexpensive switches are typically used in small networks or to add temporary workgroups to larger networks.

Managed switches support Simple Network Management Protocol (SNMP) via embedded agents and have a command line interface (CLI) that can be accessed via serial console, Telnet, and Secure Shell. These switches can often be configured and managed as groups. More recent managed switches may also support a Web interface for management through a Web browser.

These high-end switches enable network managers to remotely access a wide range of capabilities including:

  • SNMP monitoring.
  • Enabling and disabling individual ports or port Auto MDI/MDI-X.
  • Port bandwidth and duplex control.
  • IP address management.
  • MAC address filtering.
  • Spanning Tree.
  • Port mirroring to monitor network traffic.
  • Prioritization of ports for quality of service (QoS).
  • VLAN settings.
  • 802.1X network access control.
  • IGMP snooping.
  • Link aggregation or trunking.

  • Managed switches, with their extensive management capabilities, are at home in large enterprise networks where network administrators need to monitor and control a large number of network devices. Managed switches support redundancy protocols for increased network availability.

    Web-smart switches—sometimes called smart switches or Web-managed switches—have become a popular option for mid-sized networks that require management. They offer access to switch management features such as port monitoring, link aggregation, and VPN through a simple Web interface via an embedded Web browser. What these switches generally do not have is SNMP management capabilities or a CLI. Web-smart switches must usually be managed individually rather than in groups.

    Although the management features found in a Web-smart switch are less extensive than those found in a fully managed switch, these switches are becoming smarter with many now offering many of the features of a fully managed switch. Like managed switches, they also support redundancy protocols for increased network availability.

    collapse


    Black Box Explains...Fiber optic cable construction.

    Fiber optic cable consists of a core, cladding, coating, strengthening fibers, and cable jacket.

    Core
    This is the physical medium that transports optical data signals from an attached light source to... more/see it nowa receiving device. The core is a single continuous strand of glass or plastic that’s measured (in microns) by the size of its outer diameter. The larger the core, the more light the cable can carry.

    All fiber optic cable is sized according to its core’s outer diameter.

    The three multimode sizes most commonly available are 50, 62.5, and 100 microns. Single-mode cores are generally less than 9 microns.

    Cladding
    This is a thin layer that surrounds the fiber core and serves as a boundary that contains the light waves and causes the refraction, enabling data to travel throughout the length of the fiber segment.

    Coating
    This is a layer of plastic that surrounds the core and cladding to reinforce the fiber core, help absorb shocks, and provide extra protection against excessive cable bends. These buffer coatings are measured in microns (µ) and can range from 250 to 900 microns.

    Strengthening fibers
    These components help protect the core against crushing forces and excessive tension during installation.

    The materials can range from Kevlar® to wire strands to gel-filled sleeves.

    Cable jacket
    This is the outer layer of any cable. Most fiber optic cables have an orange jacket, although some types can have black or yellow jackets. collapse

    Results 31-40 of 63 < 1 2 3 4 5 > >> 
    Close

    Support

    Delivering superior technical support is our highest priority. Depending on the products or services we provide for you, please visit your appropriate support area.



     

    You have added this item to your cart.

    Important message about your cart:

    You requested more of "" than the currently available. The quantity has been changed to them maximum quantity available. View your cart.

    Print
    Black Box 1-877-877-2269 Black Box Network Services