OCPP Guides
Practical reference articles with examples, field tables, and common error fixes — written for engineers building or testing OCPP integrations.
OCPP BootNotification: Complete Guide with Examples
Required fields, valid payloads, all three CSMS response statuses, and the field-length errors you'll hit in production.
OCPP StatusNotification: Complete Guide to Connector States
Every connector state explained — Available, Preparing, Charging, SuspendedEV, SuspendedEVSE, Finishing, Faulted — with error codes and transition rules.
OCPP StartTransaction & StopTransaction: Complete Guide
The full transaction lifecycle — required fields, idTagInfo response, transactionId, all 11 stop reasons, and edge cases for outages.
OCPP Authorization: RFID, App, and Offline Auth
Online Authorize, Local Authorization List, Authorization Cache, and offline fallback strategies — idTagInfo status codes explained.
OCPP MeterValues: Reporting Energy Consumption
sampledValue structure, measurands, units, context values, and the minimum set required for billing-compliant energy reporting.
OCPP Remote Start & Stop: How CPO Apps Trigger Charging
RemoteStartTransaction full sequence, connectorId rules, profile embedding, and why Accepted ≠ session started.
OCPP Smart Charging: SetChargingProfile Explained
Profile purposes, Absolute/Recurring/Relative kind, ChargingSchedule periods, stackLevel conflict resolution, and four real-world examples.
OCPP 1.6 vs 2.0.1: What Really Changed
TransactionEvent replaces Start/Stop, Variables replace Configuration, idToken becomes an object — what you actually need to migrate.
Debugging OCPP WebSocket Disconnections
The 6 most common reasons a Charge Point drops from the CSMS — and how to diagnose each one with logs and the simulator.
OCPP Heartbeat Interval: Best Practices
Cellular cost, battery life, CSMS load — how to pick the right Heartbeat frequency and what happens when you set it wrong.
What these guides cover
Every required and optional field, type constraints, max lengths, and what CSMSes typically do with them.
A direct, 50-word answer at the top — optimized for featured snippets so you get the fact fast.
The errors engineers actually hit in production — silent truncations, ordering requirements, type mismatches.
Step-by-step testing workflows using the Validator, Builder, and Simulator on this site.
Related messages, before-and-after migration flows, and cross-version comparisons.
Each article cites the relevant section of the official Open Charge Alliance specification.