OCPP Smart Charging Profiles: TxProfile and ChargePointMaxProfile in Practice
Smart charging is the OCPP feature that turns sockets from "on/off switches" into a managed energy system. Two profiles matter most in daily operation.
ChargePointMaxProfile — the Site Ceiling
Set once by the CSMS, this profile caps the total power a station (or site) may draw. On a WANLIN-010 ten-socket station, the platform can hold the site within its circuit capacity — for example capping a 10 kW station to 6.6 kW on a 30 A feed — while the device's local strategy distributes the available power across active sockets (respecting its 4/3/3 phase layout).
TxProfile — the Per-Session Schedule
TxProfile attaches a charging schedule to a specific transaction (or transaction/connector). Use it to:
- Throttle a session during peak hours and release full power off-peak
- Guarantee an overnight "gentle" charge for battery longevity
- Enforce per-socket power limits (Wanlin sockets: 0–1000 W per socket, 0.5 A step)
Local Strategy + Platform Scheduling
Networks fail; smart charging must not. Wanlin sockets keep a local strategy layer (per-socket limits, overload shedding, no-load cut-off) that cooperates with — but does not depend on — the CSMS. If the platform is unreachable, the station keeps enforcing the last known profiles and its own safety limits; when connectivity returns, sessions and metering data are back-filled.
| Scenario | Who decides |
|---|---|
| Site circuit capacity | CSMS via ChargePointMaxProfile |
| Per-socket hardware maximum | Device configuration (1000 W) |
| Session-level schedule | CSMS via TxProfile |
| Emergency load shed | Device local strategy |
Conclusion: OCPP Smart Charging on Wanlin sockets gives operators platform-level control (billing, schedules, site caps) while the hardware guarantees safety locally. Note: current firmware supports TxProfile and ChargePointMaxProfile; ChargingStationExternalConstraints is not yet implemented.
