Request Start Transaction

Source: OCPP 2.0.1 Part 2 — Specification (Edition 2, 2022-12-15) — Section 1.44 (Messages); Use Cases F01 — Remote Start Transaction - Cable Plugin First, F02 — Remote Start Transaction - Remote Start First (Functional Block F. RemoteControl)

Overview

The CSMS sends RequestStartTransactionRequest to ask the Charging Station to start a transaction. OCPP 2.0.1 replaces the OCPP 1.6 RemoteStartTransaction with this message and adds:

A mandatory remoteStartId so the CS can echo it back in TransactionEvent (so the CSMS can correlate the eventual transaction to this request).
An optional groupIdToken for cases where reservations were made for a group.

If the transaction was already started by the CS (e.g. cable plugged in first) when this request arrives, the response may include the existing transactionId and indicate that the request "matched" an in-progress transaction.

The behaviour depends on the AuthorizeRemoteStart configuration variable: if true, the CS first authorizes via AuthorizeRequest; if false, authorization is deferred to the eventual TransactionEvent(Started).

Sequence Diagram

CSMS  ──── RequestStartTransactionRequest ────▶  Charging Station
            (evseId?, remoteStartId, idToken, chargingProfile?, groupIdToken?)
CSMS  ◀─── RequestStartTransactionResponse ────  Charging Station
            (status, transactionId?, statusInfo?)

Initiator

CSMS → Charging Station

Fields

Field Name	Field Type	Card.	Description
evseId	integer (> 0)	0..1	Optional. EVSE on which to start. Must be > 0.
remoteStartId	integer	1..1	Required. Id given by the server. CS echoes it in `TransactionEventRequest` so the CSMS can correlate.
idToken	IdTokenType	1..1	Required. The identifier the CS must use to start the transaction.
chargingProfile	ChargingProfileType	0..1	Optional. Charging Profile to use. Purpose MUST be `TxProfile`.
groupIdToken	IdTokenType	0..1	Optional. Relevant when starting on an EVSE with an active reservation for `groupIdToken` and `AuthorizeRemoteStart = false`.

Field Name	Field Type	Card.	Description
status	RequestStartStopStatusEnumType	1..1	Required. Whether the CS accepts the request.
transactionId	identifierString [0..36]	0..1	Optional. When the transaction was already started by the CS, this contains the existing `transactionId`.
statusInfo	StatusInfoType	0..1	Optional. Detailed status information.

RequestStartStopStatusEnumType values

Accepted, Rejected.

Examples

{
  "evseId": 1,
  "remoteStartId": 7,
  "idToken": { "idToken": "044943121F1A80", "type": "ISO14443" }
}

{
  "status": "Accepted"
}

Schema

Source: schemas/RequestStartTransactionRequest.json, schemas/RequestStartTransactionResponse.json (OCPP 2.0.1 FINAL)

Request schema (JSON Schema)