FOA CPCT flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Horizontal permanent link length

Maximum horizontal cable length is 90 m, from the telecommunications outlet to the horizontal cross-connect. The 10 m of equipment and patch cords brings the total channel to 100 m.

TIA-606 scope

The administration standard for telecommunications infrastructure. It defines labeling schemes, records, and identifiers so every cable, port, and pathway can be traced and documented.

TIA-607 bonding and grounding

Specifies the telecommunications bonding backbone, the main grounding busbar, and telecommunications grounding busbars. All are bonded to the building grounding electrode system to equalize potential.

Plenum cable rating CMP

CMP cable is rated for air-handling spaces and has low smoke and flame spread characteristics. Installing non-plenum cable in a plenum ceiling violates building and fire code.

Backbone fiber distance limit

Multimode backbone runs are commonly limited to about 300 m and singlemode to about 3000 m, but the exact limit depends on the application and the media selected.

Category 6A frequency

Category 6A balanced twisted-pair cable is characterized to 500 MHz and supports 10GBASE-T over full 100 m channels. It usually uses a separator or shielding to control alien crosstalk.

T568A versus T568B

T568A assigns the green pair to pins 1 and 2 and the orange pair to pins 3 and 6. T568B swaps those pairs. Both ends must match for a straight-through cable.

Untwist limit at termination

Category 6 and 6A terminations allow no more than about 13 mm of untwisted conductor. More untwisting increases near-end crosstalk and can fail certification testing.

Split pair fault

A wiring error where a conductor is paired with a conductor from a different pair. Wiremap may show continuity, but crosstalk and noise rise sharply and the link fails testing.

Characteristic impedance UTP

Unshielded twisted-pair premises cable has a nominal characteristic impedance of 100 ohms. Impedance mismatches cause reflections, which appear as return loss failures.

Stranded versus solid termination

RJ45 plugs are designed for stranded patch cable. Solid conductor cable belongs on insulation displacement connectors such as jacks and patch panels, where the blade grips the conductor.

NEXT definition

Near-end crosstalk is signal coupled from a transmitting pair into another pair, measured at the same end. Higher values in dB mean better separation between pairs.

OM3 and OM4 fiber

Laser-optimized 50/125 um multimode fiber. OM3 supports 10GBASE-SR to 300 m and OM4 to 400 m. Both use 850 nm vertical cavity surface emitting lasers.

APC connector polish

Angled physical contact connectors have an 8-degree endface, usually green. They must only mate with other APC connectors; mating with UPC or PC creates an air gap and high loss.

Singlemode core size

Singlemode fiber typically has a 9 um core and 125 um cladding. It carries one propagation mode and supports long distances at 1310 nm and 1550 nm.

Fusion splice loss

An arc-welded fusion splice typically shows about 0.1 dB loss or less, the lowest of any joining method. Mechanical splices and field-installable connectors generally show higher loss.

LC connector ferrule

The LC is a small form factor connector with a 1.25 mm ferrule and a latch. It is common in high-density patch panels and duplex fiber transceivers.

Multimode attenuation values

Typical maximum multimode attenuation is about 3.5 dB/km at 850 nm and 1.5 dB/km at 1300 nm. Singlemode is lower, about 1.0 and 0.5 dB/km.

OTDR purpose

An optical time-domain reflectometer sends pulses and measures backscatter to locate breaks, splices, and connectors, and to report distance and loss along the fiber.

Fiber bend radius

Installed fiber should not be bent tighter than about 10 times the cable outside diameter under load. Tighter bends cause macrobend loss and can crack the glass.

Copper pull tension limit

Four-pair copper cable is typically limited to 25 lbf, or about 110 N, during installation. Exceeding it stretches conductors, changes impedance, and degrades performance.

OLTS reference methods

One-jumper, two-jumper, and three-jumper reference methods produce different loss budgets. Record which method was used so test results can be compared fairly.

Wiremap test

A wiremap verifies pin-to-pin continuity and detects opens, shorts, reversed pairs, and split pairs. It does not measure crosstalk or return loss.

Certification tester setup

Select the correct test limit, such as Category 6 permanent link, and the correct cable type before testing. A wrong limit produces results that cannot be compared to the standard.

Fiber endface inspection

Inspect every connector endface with a scope before mating. A single dust particle can cause high loss or permanent scratches, so clean and re-inspect when contamination is seen.

Fiber scrap hazard

Cleaved fiber scraps are sharp and can penetrate skin or eyes. Keep safety glasses on and place all scraps in a labeled sharps container, never in ordinary trash.

Laser eye safety

Never look into a fiber or connector with the unaided eye. Use an optical power meter to confirm whether a source is live, and treat unknown fiber as energized.

Class 1 laser system

Class 1 laser products are safe under normal use because the beam is enclosed. Class 1M is safe unless optics such as magnifiers are used, so avoid viewing with lenses.

Troubleshooting high NEXT

If NEXT fails, suspect excessive untwisting at the jack, a split pair, a crushed cable, or a jack damaged during termination. Re-terminate and retest before replacing the run.

Troubleshooting high fiber loss

Check for dirty endfaces, wrong polish mating such as APC to UPC, tight bends, and damaged splices. Clean and inspect first, then measure with an OLTS or OTDR.

Pathway fill and support

Cable trays and conduits have fill limits, and cables must be supported at intervals set by code and standard. Overfilling makes pulls hard and can damage cable jackets.

Documenting test results

Save and label test results by cable identifier, matching the administration records. Results must show the test limit, date, tester, and pass or fail for each link.