ETA DCI Exam Study Guide (2026)
Everything the Data Cabling Installer (DCI) tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 75 questions |
|---|---|
| Time | 2 hours |
| Passing score | 75% |
| Format | Closed book; ETA allows scratch paper and a non-programmable calculator. DCI also requires a hands-on training course and skills check from an ETA-approved trainer or school, so this prep covers only the written knowledge exam. ETA does not publish the item format; our practice uses 4-option single-best-answer questions |
| Certifying body | ETA International (Electronics Technicians Association, International); program accredited by ICAC to ISO/IEC 17024 |
| Test provider | Taken through an ETA-approved school or trainer after its hands-on course; the written exam is proctored by an ETA Certification Administrator, online through Trapeza or on paper |
Mind map: the whole exam on one screen
Read the complete ETA DCI study notes for “Safety, Electricity and Data Communications Basics”
Our first full set of comprehensive notes, about 14 minutes of reading: Safety on the job · Ohm's law and power · Decibels · Signals and cabling performance, a worked exam example, the traps examiners use and a one-minute recap. Create a free account to read it and see how premium notes work before you decide.
1. Safety, Electricity and Data Communications Basics
ETA competency areas 1 to 4: safety and PPE, Safety Data Sheets, Ohm's law and power, noise, the telephone system and categories of twisted pair, bandwidth, decibels, attenuation and crosstalk. ETA does not publish weights for DCI areas.
Key facts
- Ohm's law: V = I x R. Power: P = V x I = I squared x R. Power lost in cabling rises with the square of the current, which matters for PoE.
- IEEE 802.3af supplies 15.4 W at the switch (PSE) and guarantees 12.95 W at the device; 802.3at 30 W and 25.5 W; 802.3bt Type 3 60 W and Type 4 90 W at the PSE.
- Decibels: 10 log for power ratios, 20 log for voltage ratios. Halving power is -3 dB; halving voltage is -6 dB.
- Attenuation (insertion loss) is signal lost along the cable; it rises with frequency and length.
- Crosstalk is coupling between pairs: NEXT at the near end, ACRF (formerly ELFEXT) at the far end, PS versions sum all disturbers, and alien crosstalk comes from neighboring cables.
- Bit rate is bits per second; baud is symbols per second; bandwidth is the frequency range a cable or signal uses (MHz).
- OSHA's Hazard Communication Standard requires Safety Data Sheets for hazardous chemicals; PPE includes eye protection, gloves, hard hats and fall protection as the task needs.
- Noise is coupled onto cabling from power lines, motors and lighting; twisting and balance cancel much of it.
Flashcards
Exam tip: Expect at least one Ohm's law or dB calculation. Write the formula first, then the numbers, and check whether the question is about power (10 log) or voltage (20 log).
2. Standards, Codes and Cable Listings
Competency areas 5 and 9: the TIA-568 family, TIA-569, 570, 606, 607, 942 and 1005, ISO/IEC 11801, IEEE 802.3 PoE and Ethernet, NEC and CEC, and UL listing tests.
Key facts
- ANSI/TIA-568.0 is the generic standard, 568.1 commercial buildings, 568.2 balanced twisted pair, 568.3 optical fiber, 568.4 broadband coax.
- TIA-569 covers pathways and spaces, TIA-570 residential, TIA-606 administration (labels and records), J-STD-607 bonding and grounding, TIA-942 data centers, TIA-1005 industrial.
- Category specified frequencies: Cat 3 to 16 MHz, Cat 5e to 100 MHz, Cat 6 to 250 MHz, Cat 6A to 500 MHz, Cat 8 to 2000 MHz.
- Category 7 and 7A are ISO/IEC classes F and FA, not recognized by TIA. Categories 1, 2, 4 and 5 are no longer recognized.
- NEC communications listings, highest to lowest: CMP (plenum, NFPA 262), CMR (riser, UL 1666), CMG or CM (general, UL 1581 tray test), CMX (limited use). A higher listing may replace a lower one.
- UL 444 covers communications cables; UL 1863 covers communications circuit accessories such as jacks.
- The NEC is NFPA 70; communications systems are in Chapter 8, and Canada uses the Canadian Electrical Code (CEC).
Flashcards
Exam tip: Make a one-line table of each TIA standard number and its subject. ETA asks which document covers a task as often as what the document says.
3. Network Design and Cabling System Structure
Competency areas 6, 10, 14, 15, 16 and 17: OSI and Ethernet layers, topologies, the hierarchical star, distributors, spaces, active equipment, wireless links and cabling design limits.
Key facts
- TIA-568.0 generic cabling is a hierarchical star. In a commercial building Distributor C is the main cross-connect (MC), B the intermediate cross-connect (IC) and A the horizontal cross-connect (HC).
- Backbone cabling has at most two levels of cross-connect: MC to IC to HC.
- Horizontal cable is 90 m maximum regardless of media. Cords in a horizontal channel total 10 m maximum, giving a 100 m channel.
- Cord guidance: MC or IC jumpers 20 m maximum, HC patch cords 5 m, work area cords 5 m.
- Provide at least one telecommunications room per floor, and more rooms or enclosures when the area served exceeds 1000 m² (10,000 ft²) or outlets are beyond 90 m.
- The entrance facility connects access provider cabling; equipment rooms hold the MC and complex equipment; TRs hold the HC.
- IEEE 802.3 Ethernet spans the physical layer and the MAC sublayer of the data link layer; switches work at layer 2, routers at layer 3.
- Open offices use multi-user outlets (MUTOAs) or consolidation points; only one consolidation point is allowed per horizontal link.
Flashcards
Exam tip: Draw the hierarchical star once with EF, ER, MC, IC, TR, HC and work area, and add the 90 m, 10 m and 20 m limits in their places.
Test yourself on these topics
Take the free 15-question ETA DCI test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Copper Media, Cable Construction and Performance
Competency areas 7, 8 and 12: twisted-pair construction to TIA-568.2, coaxial types, mechanical limits, transmission performance, hybrid and composite cables, and 66 and 110 blocks.
Key facts
- Horizontal cable is four balanced twisted pairs of 22 to 24 AWG solid conductors in a thermoplastic jacket; insulated conductor diameter 1.53 mm maximum.
- Minimum breaking strength 400 N (90 lbf); maximum installation tension per 4-pair cable 110 N (25 lbf).
Flashcards
Exam tip: Many questions mix up the 400 N breaking strength and the 110 N pulling limit, or the 4x and 8x radii. Learn each pair together.
5. Tools, Connectors and Termination
Competency areas 11, 13 and 19: strippers, crimpers, punch-down tools, fish tape, T568A and T568B, USOC, coax F and BNC connectors, wall plates, MUTOAs and modular plug terminated links.
Key facts
- Each 4-pair horizontal cable ends in an 8-position modular jack at the work area.
- T568A: pins 1-2 white/green and green, pins 3-6 white/orange and orange. T568B swaps the green and orange pairs. Blue is on 4-5 and brown on 7-8 in both.
Flashcards
Exam tip: Write T568A and T568B pin-outs from memory every day of your prep week. Pin-out errors are the easiest marks to lose.
6. Cabling Installation, Bonding and Firestopping
Competency area 18: installation steps, pulling, aerial and underground safety, dressing and support, TIA-606 labels, the 4-pair and binder color codes, J-STD-607 bonding, NEC Article 250 and firestopping.
Key facts
- Plan pathways, pull, dress, terminate, label, test and document, in that order.
- Support cable with J-hooks, trays or rings; avoid overtightened ties that deform the jacket.
Flashcards
Exam tip: Bonding questions use the new 607-D names. If you learned TMGB and TGB, map them to PBB and SBB before the exam.
7. Testing, Troubleshooting and Documentation
Competency areas 20, 21 and 22: permanent link and channel certification, required tests, PoE and resistance unbalance, shield integrity, wire map faults, troubleshooting method and TIA-606 records.
Key facts
- The permanent link is the fixed cable from patch panel to outlet (90 m maximum); the channel adds patch and equipment cords (100 m maximum).
- Minimum tests for Category 5e: wire map, length, insertion loss and NEXT; certification testers add return loss, ACRF, PS values and delay.
Flashcards
Exam tip: When a question lists symptoms, ask which tester would actually see the fault. That usually rules out two options straight away.
How to pass
- ETA writes the DCI to its own competency list, which cites ANSI/TIA-568.0-E, 568.1-E, 568.2-D, TIA-569-E, TIA-606-C, J-STD-607-D and the NEC. Learn the numbers those clauses give: 90 m horizontal, 10 m of cords, 25 lbf pulling tension, 4x and 8x bend radius.
- You need 75%, so about 57 of 75 correct, in 2 hours: well over a minute per question. Use the spare time on dB and Ohm's law arithmetic, and bring a non-programmable calculator.
- Know your color codes cold: T568A and T568B pin-outs, the 4-pair order and the 25-pair tip/ring scheme. Several competencies turn on them.
- Testing questions often hinge on what each tester can see: a wire map finds opens, shorts and miswires, but crosstalk, insertion loss and alien crosstalk need a certification tester.
Frequently asked questions
How long should I study for the ETA DCI exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Can I take the ETA DCI exam online?
BICSI's v15 handbook describes the RCDD exam at Pearson VUE test centers, not remote proctoring. Format: closed book; eta allows scratch paper and a non-programmable calculator. dci also requires a hands-on training course and skills check from an eta-approved trainer or school, so this prep covers only the written knowledge exam. eta does not publish the item format; our practice uses 4-option single-best-answer questions. Check pearsonvue.com/bicsi for the options in your country.
What score do I need to pass the ETA DCI exam?
75%. The exam has 75 questions and a time limit of 2 hours.
What are the most tested topics?
The outline covers safety, electricity and data communications basics, standards, codes and cable listings, network design and cabling system structure, copper media, cable construction and performance, tools, connectors and termination, cabling installation, bonding and firestopping, testing, troubleshooting and documentation. Use the free practice test to see which ones you need most.
The premium ETA DCI study path
Premium ETA DCI prep is studied one topic at a time. Each step starts with that topic's key notes and flashcard deck, then its own question sets of 25, so you master one topic before you move to the next. When every topic is strong, the 6 full mock exams show you're ready.
Your step-by-step study path
- 1Safety, Electricity and Data Communications Basics9 key notes, 115 flashcards, then 450 practice questions in 18 sets of 25Notes free with an account
- 2Standards, Codes and Cable Listings9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 3Network Design and Cabling System Structure9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 4Copper Media, Cable Construction and Performance9 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 5Tools, Connectors and Termination8 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 6Cabling Installation, Bonding and Firestopping8 key notes, 115 flashcards, then 425 practice questions in 17 sets of 25Premium
- 7Testing, Troubleshooting and Documentation8 key notes, 110 flashcards, then 425 practice questions in 17 sets of 25Premium
- Final step: 6 full mock exams75 questions each, timed like test day. Pass them, then book your exam.Premium
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- The RCDD exam: full prep for the v15 blueprint
- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
- Readiness Score & detailed reports
- Video lessons as they release
- Content updates during your access
- 5 bonuses: numbers and formulas sheet, standards atlas, study planner and more
- Pass Guarantee: complete the prep, pass or 100% back
Renews once a year until you cancel. We email you before each renewal. Cancel any time from your account; you keep access until the end of the year you've paid for.
Summarized from BICSI's official candidate information and the rules cited, checked October 2026. Confirm current requirements with ETA International (Electronics Technicians Association, International); program accredited by ICAC to ISO/IEC 17024.