Alien crosstalk is the coupling of noise from one cable link to another. This happens if one cable is surrounded by many other cables in a bundle. We identify the cables that surround a cable in a bundle as Disturbers. Cables that can suffer from noise coupling from other cables are identified as the Disturbed cable or (Victim).This becomes more important as we increase the bandwidth requirement of cables for faster applications and the surrounding cables (Disturbers) impact the ability of the disturbed cable (Victim) to transmit data. You might think that using shielded cables i.e. (where there is at least an outer shield) then alien crosstalk would not be a problem. However, if the shield is not terminated correctly even a shielded system can fall foul of alien crosstalk.
Fluke Networks, Hirose and Harting have released an adapter supporting the ix Industrial connector for Fluke’s DSX CableAnalyzer family of network cabling certification tools. The ix Industrial is a rugged Ethernet connector for harsh environments, based on IEC 61076-3-124 standard with a 70% smaller size than the traditional 8-pin modular (“RJ-45”) connector. The new adapter allows the DSX Series to connect to cabling systems employing the ix Industrial connector for the purposes of pre-startup verification and troubleshooting.
When it comes to testing fiber systems, connector loss refers to the loss of a mated pair of connectors – it’s actually impossible to measure a single connector. To test the loss of the first connector, it must be mated to a similar, known quality connector. That’s where Test Reference Cords (TRCs) come in. But you’ve got to take into account the loss of the TRCs by calibrating your tester to 0 dB of loss. This is done by setting a reference, and it is the most important step in Tier 1 fiber testing using an optical loss test set (OLTS). Setting a reference needs to be done whenever the TRC has been removed from the output port on your tester, and whenever the TRC has been cleaned and inspected.
OM3 and OM4 multimode fiber are two common types of fiber used in local area networks–typically in backbone cabling between telecommunications rooms and in the data center between main networking and storage area network (SAN) switches. Both of these fiber types are considered laser-optimized 50/125 multimode fiber, meaning they both have a 50 micron (µm) diameter core and a 125 µm diameter cladding, which is a special coating that prevents light from escaping the core. Both fiber types use the same connectors, the same termination and the same transceivers–vertical-cavity surface emitting lasers (VCSELs) that emit infrared light at 850 nanometers (nm). So, what’s different?
Avoid using any type of alcohol, including isopropyl or rum to clean your fiber or your endfaces will look like the attached screenshot. Stick with solvents specifically engineered for the purpose.
The use of Ethernet for industrial automation applications is on the rise and is rapidly displacing traditional Fieldbus protocols that are more complex, often proprietary and have limited distance and performance. In fact, Industrial Ethernet is now bigger than traditional Fieldbus and growing at an annual rate nearly four times that of Fieldbuses. Download this White Paper from Fluke Networks to learn more.
When it comes to testing a cabling installation, there are essentially three choices–verification, qualification and certification. Verification is great for troubleshooting as it will tell you if your cabling is connected correctly and can help you find breaks, connectors and splices. Qualification lets you know if your cable under test will support a specific application, making it great for small moves, adds and changes or determining if an existing cable plant can support an application. But only certification will tell you if the cable plant fully meets industry standards – it’s the only test that measures across predefined ranges and compares the results to TIA, ISO and IEEE specifications to determine if a link is compliant with a specific category or class of cable and able to support the application. Certification is also what most cable manufacturers require for a warranty.
In today’s fast-paced workplace maximizing productivity is essential. Whether installing new fiber links or troubleshooting an existing network, the faster you can locate a problem, the faster you can fix it. Fluke’s visual fault cable continuity tester locates fibers, finds faults, and verifies continuity.
Insertion loss budgets have gotten tighter as we have moved from 10 to 40/100 Gig for multimode fiber applications. One would think that we can’t say the same for singlemode applications that have historically meant larger loss budgets – 6.3 dB for 100 Gig over singlemode (100GBASE-LR4) versus just 1.9 dB for 100 Gig over multimode (100GBASE-SR4). But that’s no longer the case with new short-reach singlemode applications. And it’s not just insertion loss that matters with these applications; you now need to also be concerned with reflection.
Let’s take a look at the #9 Dumb Thing that smart people do when testing network cabling systems—relying on a duplex tester for certifying MPO trunks. Field testing is the only way to ensure that MPO links meet the application performance requirements. Despite the fact that pre-terminated MPO fiber cables are manufactured and tested by vendors to comply with ANSI/TIA and international standards, there are many factors that can potentially impact performance. First of all, MPO connectors are harder to clean than duplex connectors. The 12-fiber MPO interface features an array with a much larger surface area, which unfortunately makes it easier to move contaminants from one fiber to another within the same array during the cleaning process. 40 and 100 Gbps MPO fiber applications also have much lower loss budgets so it’s important to ensure the highest testing accuracy as possible.