Data Transfer (Charging Station → CSMS)

Source: OCPP 2.0.1 Part 2 — Specification (Edition 2, 2022-12-15) — Section 1.13 (Messages); Use Cases P01 / P02 (Functional Block P. DataTransfer)

Note: DataTransfer is bidirectional. This file describes the CS-initiated direction (P02 — Data Transfer to the CSMS). For the CSMS-initiated direction (P01) the wire format is identical.

Overview

When the Charging Station needs to send vendor-specific information to the CSMS for functionality not covered by OCPP, it uses DataTransferRequest. The vendorId identifies the vendor-specific implementation (RECOMMENDED to be reverse-DNS), and the optional messageId distinguishes individual messages within that vendor's namespace. The shape and length of data is open to implementation and must be agreed by both parties.

Status semantics:

Accepted / Rejected — implementation-specific, decided by the receiving side.
UnknownVendorId — recipient has no implementation for the given vendorId. data SHALL be absent.
UnknownMessageId — recipient does not recognize the given messageId.

Sequence Diagram

Charging Station  ──── DataTransferRequest ────▶  CSMS
                       (vendorId, messageId?, data?)
Charging Station  ◀─── DataTransferResponse ────  CSMS
                       (status, data?, statusInfo?)

Initiator

Charging Station → CSMS (this file). Also CSMS → CS (P01).

Fields

Field Name	Field Type	Card.	Description
vendorId	string [0..255]	1..1	Required. Identifies the vendor-specific implementation.
messageId	string [0..50]	0..1	Optional. May be used to indicate a specific message or implementation.
data	anyType	0..1	Optional. Data without specified length or format. Must be agreed by both parties.

Field Name	Field Type	Card.	Description
status	DataTransferStatusEnumType	1..1	Required. Indicates success or failure of the data transfer.
data	anyType	0..1	Optional. Data without specified length or format, in response to request.
statusInfo	StatusInfoType	0..1	Optional. Detailed status information.

DataTransferStatusEnumType values

Accepted — Message accepted, request is accepted.
Rejected — Message accepted, but the contained request is rejected.
UnknownMessageId — Message could not be interpreted due to unknown messageId.
UnknownVendorId — Message could not be interpreted due to unknown vendorId.

Examples

{
  "vendorId": "com.vendorx.charging",
  "messageId": "TelemetryUpload",
  "data": { "voltage": 230.4, "freq": 50.02 }
}

{
  "status": "Accepted",
  "data": { "ack": true }
}

Schema

Source: schemas/DataTransferRequest.json, schemas/DataTransferResponse.json (OCPP 2.0.1 FINAL)

Request schema (JSON Schema)

Response schema (JSON Schema)