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Numbering

EVSE numbering​

To enable the CSMS to address all the EVSEs of a Charging Station, EVSEs MUST always be numbered in the same way. EVSEs numbering (evseIds) MUST be as follows:

  • The EVSEs MUST be sequentially numbered, starting from 1 at every Charging Station (no numbers may be skipped).
  • evseIds MUST never be higher than the total number of EVSEs of a Charging Station
  • For operations initiated by the CSMS, evseId 0 is reserved for addressing the entire Charging Station.
  • For operations initiated by the Charging Station (when reporting), evseId 0 is reserved for the Charging Station main controller.

Example: A Charging Station with 3 EVSEs: All EVSEs MUST be numbered with the IDs: 1, 2 and 3. It is advisable to number the EVSEs of a Charging Station in a logical way: from left to right, top to bottom incrementing.

Connector numbering​

To enable the CSMS to address all the Connectors of a Charging Station, Connectors MUST always be numbered in the same way. Connector numbering (connectorIds) MUST be as follows:

  • The connectors are numbered (increasing) starting at connectorId 1 on every EVSE
  • Every connector per EVSE has a unique number
  • ID of the first Connector of an EVSE MUST be 1
  • Additional Connectors of the same EVSE MUST be sequentially numbered (no numbers may be skipped)
  • connectorIds MUST never be higher than the total number of connectors on that EVSE

Example: A Charging Station with 3 EVSEs that each have 2 connectors, is numbered as follows:

  • EVSE 1 has connectors with connectorId 1 and 2
  • EVSE 2 has connectors with connectorId 1 and 2
  • EVSE 3 has connectors with connectorId 1 and 2

Transaction IDs​

TransactionIds are now generated by the Charging Station and MUST be unique on this Charging Station for every started transaction.

In OCPP 1.x this was done by the CSMS.

The format of the transaction ID is left to implementation. This MAY for example be an incremental number or an UUID.