You have probably noticed that a socket shows green, blue or red on a charging map. Behind those colours there is usually a single OCPP message: StatusNotification. The charger uses it to inform the management software whenever the status of one of its connectors changes. Reading the statuses correctly matters for both driver experience and fault management.

When is StatusNotification sent?

  • For each connector after the charger starts and its BootNotification is accepted,
  • When a connector's status changes (cable plugged in, charging started, fault occurred and so on),
  • When the CSMS requests status information with TriggerMessage.

In OCPP 1.6J the message must contain the connectorId, status and errorCode fields. A timestamp, a vendor-specific error code and a description can also be sent optionally.

OCPP 1.6J connector statuses

  • Available: The connector is free and ready to accept a new user.
  • Preparing: The user has tapped a card or plugged in the cable; the preparation stage before charging starts.
  • Charging: Energy is being transferred.
  • SuspendedEVSE: The transaction is open but the charger is not delivering energy (for example, smart charging has reduced the limit to zero).
  • SuspendedEV: The transaction is open but the vehicle is not drawing energy (the battery is full or the vehicle is delaying charging).
  • Finishing: The transaction has ended; the cable is still plugged in or the user has not left yet.
  • Reserved: The connector is reserved for a user.
  • Unavailable: The connector has been taken out of service (for example with ChangeAvailability).
  • Faulted: The connector cannot be used because of a fault.

connectorId: 0 has a special meaning and represents the whole charger rather than a connector. See our article on what connectorId 0 means for details.

Statuses in OCPP 2.0.1 and 2.1

In 2.0.1 the status list was simplified: Available, Occupied, Reserved, Unavailable, Faulted. The detailed stages of charging (cable plugged in, energy flowing, vehicle pausing) are now tracked in the chargingState field of the TransactionEvent message. This separates the question "is the socket occupied?" from "what stage is the charging at?".

The errorCode field

When the status is Faulted, the errorCode field shows the type of problem: GroundFailure, OverCurrentFailure, HighTemperature, ConnectorLockFailure, PowerMeterFailure, ReaderFailure and so on. An error code can also be sent as a warning even when the status is not Faulted. We cover the meaning of these codes and the first response steps in detail in our OCPP error codes guide.

Interpreting statuses correctly

SuspendedEV is not always a problem

When the vehicle battery is full or the vehicle postpones charging with its own timer, the connector moves to SuspendedEV. That is normal. But if SuspendedEV appears for a long time at the start of a session, there may be a communication issue between the vehicle and the charger. See our article on SuspendedEV and SuspendedEVSE for details.

Getting stuck in Preparing

If the user plugged in the cable but did not authorise, or authorisation failed, the connector can stay in Preparing. This directly affects the driver experience; see charging stuck in Preparing.

Finishing and bay occupancy

If charging has finished but the vehicle has not left, the connector stays in Finishing. At public sites, tracking this time is the core data for an idle fee policy.

Monitoring and alerts

Showing status messages in real time is not enough; their history must be stored as well. How many times a day a connector drops into Faulted, how long it stays Unavailable or the average Finishing time are valuable indicators for business decisions. Üreticy's OCPP software shows the live status of every station and socket on a map and raises instant alerts on faults and disconnections.

Indicators you can derive from status data

When StatusNotification history is stored properly, you can calculate:

  • Availability (uptime): The share of time a connector spends outside Faulted or Unavailable.
  • Utilisation: The ratio of Charging and SuspendedEV time to total time.
  • Average occupancy time: The time from Preparing back to Available.
  • Fault frequency: The number of Faulted transitions in a period and the most common errorCode.

These indicators show concretely which location needs a new charger or which model fails more often.

Conclusion

StatusNotification is the pulse of a charging network. Reading the Available, Charging, Suspended, Finishing and Faulted statuses correctly lets you give drivers accurate information, respond quickly to faults and manage car park usage.