Is a CSMS the same as a CPMS?

Yes, both name the operator's backend. OCPP 1.6 calls it the Central System, OCPP 2.0.1 and 2.1 the charging station management system (CSMS); CPMS is the common industry term.

Explained in

OCPP in depth · Stop 03How do the OCPP versions differ?OCPP 1.6, 2.0.1 and 2.1 side by side: what changed, why 2.0.1 is not backward compatible, and which version supports which AFIR requirement.

OCPP 1.6 speaks of the Charge Point and the Central System; from OCPP 2.0.1 on, they are the charging station and the charging station management system, CSMS, and OCPP 2.1 keeps these names. The roles stay the same. This site uses the industry term CPMS, charge point management system, for the backend in every version.

From “Same roles, new names”, stop 03

Terms

  1. OCPPOpen Charge Point Protocol: the open protocol between a charger and its operator's backend.
  2. CPMSCharge point management system: the operator's software backend that monitors and controls the chargers. OCPP calls it the Central System in version 1.6 and the CSMS, charging station management system, from version 2.0.1 on.
  1. What is the difference between OCPP 1.6 and 2.0.1?OCPP 2.0.1 is not backward compatible with 1.6: transactions became configurable and unified, and the device model was added. OCPP 2.1 builds on 2.0.1 and keeps it compatible.
  2. How does a charger connect to the backend?The charger opens a WebSocket to its backend, announces itself and then checks in at a set interval. Commands from the backend travel over the same connection.
  3. How secure is OCPP?OCPP has three security profiles. Profile 2 adds TLS and a backend certificate, profile 3 certificates on both sides; profile 1 is not recommended for the field.
  4. Which OCPP messages make up a charging session?In OCPP 1.6: Authorize, StartTransaction, MeterValues and StopTransaction. In 2.0.1, the transaction messages are events of one type, TransactionEvent.
  1. Open Charge Alliance: OCPP 1.6 Security Whitepaper, edition 4, February 2026. https://openchargealliance.org/ocpp-info-whitepapers/ocpp-1-6-security-whitepaper-4th-edition/. Checked 09 Oct 2026. Licence: CC BY-ND 4.0.
  2. Open Charge Alliance: What is new in OCPP 2.0.1? Whitepaper, version 1.0, March 2023. https://openchargealliance.org/wp-content/uploads/2024/01/new_in_ocpp_201-v10.pdf. Checked 09 Oct 2026. Licence: CC BY-ND 4.0.