THE UK CABLING FIELD GUIDE
Find the fault.
Prove the fix.
Practical Ethernet, cable tracing and PoE guidance for the people who install it—and get called back when it stops working.
START WITH THE SYMPTOM
Search all guides and fault types →
01 / THE FIELD SEQUENCE
A useful next check. Not another guess.
Start with the observed symptom and check the simplest alternative explanation before replacing equipment. Confirm port capabilities for a slow link, power requirements for a restarting camera, and connection state before tracing a cable. Change one variable at a time and record whether the original problem returns after each change.
Eight lights. Still no gigabit.
Before connecting: Disconnect active equipment before passive wiremap tests.
- Next check
- Check the negotiated rate at both ends; compare with a known-good short lead.
- Capability needed
- Wiremap with explicit split-pair detection; qualification when application support is the question.
- Keep this evidence
- Before/after link rate, pin map and controlled substitution.
Power present. Camera restarting.
Before connecting: Confirm the PoE type and the instrument’s permitted powered connection.
- Next check
- Check uptime, port limit and shared budget; repeat the failing IR or PTZ mode.
- Capability needed
- A compatible inline meter or load-capable tester, depending on the question.
- Keep this evidence
- Measurement point, operating mode, duration and loaded readings.
One outlet. A crowded cabinet.
Before connecting: Check whether the link is disconnected, active or supplying PoE.
- Next check
- Choose a permitted identification mode, then confirm the candidate before unplugging.
- Capability needed
- A compatible tracer, remote ID or supported switch-port identification function.
- Keep this evidence
- Cable state, candidate, confirmation method and restored service.
A PASS needs a test limit.
Before connecting: Match the test method, adapters and connection state to the required result.
- Next check
- Identify whether the job needs wiring verification, application qualification or certification.
- Capability needed
- The instrument class and configuration required by the acceptance specification.
- Keep this evidence
- Selected limit, link identity, instrument details and complete result.
02 / MATCH THE TEST TO THE QUESTION
What does your tester actually prove?
Verification checks basic wiring, qualification assesses support for a stated network application, and certification measures a link against a selected cabling standard. A cable tracer or PoE detector answers a different question. Choose the capability required by the job, then check the exact instrument’s manual and limitations before interpreting a PASS.
- 01Verification · wiremap
Which pin connects to which pin at the other end?
Does not establish: A correct pin map alone does not prove transmission performance. - 02Qualification
Can this link support the selected network application under the test method?
Does not establish: The full category/Class certification test set. A negotiated link rate alone is not qualification. - 03Certification
Does this link meet the selected cabling standard and limit?
Does not establish: Network configuration, internet service or every future patch lead. - 04PoE under load
How does the supply behave under the applied or observed load?
Does not establish: A single operating point does not prove all loads, durations or cable certification.
PoE under load is a separate power-delivery question, not a higher level of cable certification.
Compare all eight capabilities ↗03 / REFERENCE DESK
The fundamentals, drawn clearly.
Use the wiring and measurement references to understand what a result can mean before taking the next step. Pin assignments, physical pair membership and electrical distance describe different aspects of a cable. The diagrams explain those distinctions; they are not photographs of tested samples or evidence that a particular instrument has passed a bench test.
- Wiring referenceT568A vs T568B: what changes and what does not
Compare T568A and T568B pin assignments, physical pair membership and termination checks using an explicit numbered diagram.
6 min read - Measurement limitsCable length and distance-to-fault: what a tester can estimate
Understand electrical distance, NVP, reference points and far-end conditions before using a cable tester’s length or distance-to-fault reading.
6 min read - PoE measurementPoE identification vs loaded measurement: what each result means
Distinguish PoE detection, advertised power, inline observation and applied-load testing before diagnosing a camera or switch.
6 min read
THE FAULT REFERENCE
Same pins.
Different pair.
A split pair can connect matching pins at both ends while using conductors that are not physically twisted together as required. A simple continuity sequence can therefore pass without proving correct pairing. Compare seven fault types in the illustrated reference, then record what your actual instrument shows under the stated conditions.
Explore the fault library ↗HOW WE WORK
Useful guidance. Visible sources.
These guides explain manufacturer documentation and attributed technical cases, with the limits of each source kept alongside the claim. Fluke’s testing guidance distinguishes verification, qualification and certification; the FOA illustrates wiremap faults. Our fault drawings explain the principles, while original measurements will be labelled only after the tests have actually been performed.