Loading


Categories (x) > Testers & Tools > Testers (x)

Results 21-30 of 63 < 1 2 3 4 5 > >> 
  • Video...New Cabling Solutions

    From DisplayPort cables and RG-6 quad-shield coax to handy retractable cables, this webinar covers all the latest new cabling products.


Product Data Sheets (pdf)...Quick Test RS-232

  • Quick Start Guide... 
  • Cable Inspector Cable Tester Quick Start Guide
    Quick Start Guide for the CICT (Version 1)
 
  • Quick Start Guide... 
  • Deluxe Light Source Quick Start Guide (QSG)
    Quick Start Guide (QSG) for the FOLS-SM-200 and FOLS-MM-200.
 
  • Quick Start Guide... 
  • Visual Fault Locator for Fiber Quick Start Guide (QSG)
    Quick Start Guide (QSG) for the FOVFL.
 

Black Box Explains...Power over Ethernet (PoE).

What is PoE?
The seemingly universal network connection, twisted-pair Ethernet cable, has another role to play, providing electrical power to low-wattage electrical devices. Power over Ethernet (PoE) was ratified by the... more/see it nowInstitute of Electrical and Electronic Engineers (IEEE) in June 2000 as the 802.3af-2003 standard. It defines the specifications for low-level power delivery—roughly 13 watts at 48 VDC—over twisted-pair Ethernet cable to PoE-enabled devices such as IP telephones, wireless access points, Web cameras, and audio speakers.

Recently, the basic 802.3af standard was joined by the IEEE 802.3at PoE standard (also called PoE+ or PoE plus), ratified on September 11, 2009, which supplies up to 25 watts to larger, more power-hungry devices. 802.3at is backwards compatible with 802.3af.

How does PoE work?
The way it works is simple. Ethernet cable that meets CAT5 (or better) standards consists of four twisted pairs of cable, and PoE sends power over these pairs to PoE-enabled devices. In one method, two wire pairs are used to transmit data, and the remaining two pairs are used for power. In the other method, power and data are sent over the same pair.

When the same pair is used for both power and data, the power and data transmissions don’t interfere with each other. Because electricity and data function at opposite ends of the frequency spectrum, they can travel over the same cable. Electricity has a low frequency of 60 Hz or less, and data transmissions have frequencies that can range from 10 million to 100 million Hz.

Basic structure.
There are two types of devices involved in PoE configurations: Power Sourcing Equipment (PSE) and Powered Devices (PD).

PSEs, which include end-span and mid-span devices, provide power to PDs over the Ethernet cable. An end-span device is often a PoE-enabled network switch that’s designed to supply power directly to the cable from each port. The setup would look something like this:

End-span device → Ethernet with power

A mid-span device is inserted between a non-PoE device and the network, and it supplies power from that juncture. Here is a rough schematic of that setup:

Non-PoE switch → Ethernet without PoE → Mid-span device → Ethernet with power

Power injectors, a third type of PSE, supply power to a specific point on the network while the other network segments remain without power.

PDs are pieces of equipment like surveillance cameras, sensors, wireless access points, and any other devices that operate on PoE.

PoE applications and benefits.
• Use one set of twisted-pair wires for both data and low-wattage appliances.
• In addition to the applications noted above, PoE also works well for video surveillance, building management, retail video kiosks, smart signs, vending machines, and retail point-of-information systems.
• Save money by eliminating the need to run electrical wiring.
• Easily move an appliance with minimal disruption.
• If your LAN is protected from power failure by a UPS, the PoE devices connected to your LAN are also protected from power failure.
collapse

  • Manual... 
  • Cable Inspector Cable Tester User Manual
    User Manual for the CICT (Version 1)
 
  • Manual... 
  • Deluxe Light Source Manual
    Manual for the FOLS-SM-200.
 

Using optical break locators and OTDRs.

An optical time-domain reflectometer, or OTDR, is an instrument used to analyze optical fiber. It sends a series of light pulses into the fiber under test and analyzes the light... more/see it nowthat is scattered and reflected back. These reflections are caused by faults such as breaks, splices, connectors, and adapters along the length of the fiber. The OTDR is able to estimate the overall length, attenuation or loss, and distance to faults. It’s also able to “see” past many of these “events” and display the results. The user is then able to see all the events along the length of the fiber run.

However, OTDRs do have a weakness?—?a blind spot that prevents them from seeing faults in the beginning of the fiber cable under test. To compensate for this, fiber launch boxes are used. Launch boxes come in predetermined lengths and connector types. These lengths of fiber enable you to compensate for this blind spot and analyze the length of fiber without missing any faults that may be in the first 10–30 meters of the cable.

An optical break locator, or OBL, is a simplified version of an OTDR. It’s able to detect high-loss events in the fiber such as breaks and determine the distance to the break. OBLs are much simpler to use than an OTDR and require no special training. However, there are limitations. They can only see to the first fault or event and do not display information on the portion of fiber after this event. collapse


Product Data Sheets (pdf)...TVR 10/100/1000 Tester

Results 21-30 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.



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