About
About CertifBus
CertifBus is an independent practice question bank for industrial and commercial bus protocol certifications. The project exists because preparing for KNX Basic, BACnet, PROFINET, Modbus, OPC UA, CMVP, DALI-2, EnOcean, Matter or LoRaWAN today happens in vendor silos (Siemens, Beckhoff, Honeywell, Schneider) or via dated PDFs floating in forums.
We offer an alternative: 1,300+ trilingual questions (French, English, German) with detailed corrections, cited public sources, no sign-up to read. 240 questions are free (10 per certification × 2 modes); the remaining 1,060 are available via a one-shot purchase.
Editorial methodology
Every question is written from official public sources: ISO/IEC specifications, ASHRAE standards, KNX Association docs, OPC Foundation, BACnet International, LoRa Alliance, Modbus Organization, EVO IPMVP documentation.
Production pipeline:
1. Per-protocol framing (official topic blocks)
2. First draft in French (source language) from public specifications
3. Automated editorial audit (Sonnet 4.6) — factual error detection, inconsistencies, bias
4. 65 questions still under human review (audit V2 in progress, see docs/audit/needs-review.md in the public repo)
5. Native English and German rewriting (no DeepL, no Google Translate — native writers or LLM agents briefed in the target language)
The 240 questions exposed in free access are selected to match Google high-intent queries per protocol — the current selection is being re-prioritised against an internal SEO market study (docs/seo-market-research.md in the repo).
Cited sources
Each question references its public source where available:
- KNX Association — ETS Inside Help, KNX Specification 3/3/2 and 3/5/1, KNX Secure System Description
- ASHRAE / BACnet International — ANSI/ASHRAE 135-2020, BACnet Standards & Test Lab (BTL)
- PROFIBUS & PROFINET International (PI) — IEC 61158/61784, GSDML reference, PROFIsafe IEC 61784
- Modbus Organization — Modbus Application Protocol V1.1b3
- OPC Foundation — IEC 62541 (Parts 1-100+), Companion Specifications PA-DIM, AutoID, Robotics, FX
- Connectivity Standards Alliance (CSA) — Matter Specification 1.0 → 1.5
- LoRa Alliance — LoRaWAN L2 Specification 1.0.4 and 1.1, Regional Parameters
- DALI Alliance — IEC 62386, D4i specification
- EnOcean Alliance — EnOcean Equipment Profiles (EEP), ESP3 Serial Protocol
- Efficiency Valuation Organization (EVO) — IPMVP Volume I 2022, CMVP Body of Knowledge v3
Expert review
We are actively recruiting a certified KNX Tutor to review every published question and flag the validated ones via schema.org `Question.reviewedBy`. Target profile: KNX Partner Advanced minimum, ideally KNX Tutor with 5+ years of teaching experience.
Same approach for the other high-volume protocols (BACnet, OPC UA, CMVP). If you're interested or know someone who could be, reach out via the profile page.
In the meantime, each question is sourced from (a) a cited official public source, (b) an automated editorial audit (Sonnet 4.6 on 1,328 questions; 1,220 validated, 108 corrected, 65 under human review).
Founder · Engineering
Alexandru
Product design, technical architecture, question selection and sourcing, monitoring of bus protocol standards and updates. Independent.
AI co-author · under human supervision
Claude (Anthropic)
First-draft writing, automated editorial audit (factual inconsistency detection), multilingual translations. Every factual claim is traceable to a public source cited on the relevant question.
Role open
KNX Tutor reviewer (currently recruiting)
Certified KNX Partner Advanced (ideally KNX Tutor) with 5+ years of field and teaching experience. Will validate each published question via the schema.org Question.reviewedBy field. Reach out via the legal notice if interested.
Independence
CertifBus is not affiliated with any certification body or manufacturer. No protocol association (KNX Association, BACnet International, OPC Foundation, etc.) controls our editorial choices or receives any royalty on our sales.
Our funding sources: one-shot purchases of premium question banks (from €19) and, eventually, training partnerships explicitly flagged as such.
KNX®, BACnet®, PROFINET®, PROFIBUS®, Modbus®, OPC UA®, Matter®, LoRaWAN®, DALI-2®, EnOcean® are trademarks of their respective owners. We name them descriptively without implication of endorsement.
Contact
For editorial questions, training partnerships, or if you spot a factual error in a question, contact us via the profile page (signed-in area) or the legal notice. We fix factual errors within 7 days of confirmation.