Open Charge Point Protocol (OCPP)

Definition of Open Charge Point Protocol (OCPP)

Open charge point protocol (OCPP) is an open, standardized communication protocol that defines how EV charging stations (charge points) talk to central management systems (CPMS / CSMS). Instead of every charger speaking its own proprietary language, OCPP gives the entire ecosystem a common “syntax” so that hardware and software from different vendors can work together seamlessly.

In practice, OCPP allows:

• Starting and stopping charging sessions remotely.
• Monitoring charger status (available, in use, faulted, offline).
• Collecting energy‑consumption data for billing and analytics.
• Pushing configuration and firmware updates to chargers.
• Enabling smart charging, load balancing, and grid‑aware behavior.
  
  

Because OCPP is open and non‑proprietary, it encourages competition and innovation while reducing vendor lock‑in. Any manufacturer or software developer can implement OCPP, which is why it has become the de facto standard in most modern EV charging networks.

How OCPP works

OCPP defines two main roles:

• Charge Point (client): the physical EV charger that sends status updates and receives commands.
• Central System (server): the backend CPMS that monitors, controls, and reports on the chargers.
  
  

These two entities communicate over secure, message‑based channels, exchanging standardized messages for things like:

• Heartbeats and status reports.
• Start/stop transactions.
• Meter values and fault codes.
• Configuration and firmware updates.
  
  

This structure makes it possible for a single CPMS to manage a multi‑brand network of chargers, as long as they are OCPP‑compliant.

Why OCPP matters for operators and asset managers

For CPOs, site hosts, and energy companies, OCPP is foundational because it:

• Enables interoperability between chargers and management platforms.
• Supports smart charging and load balancing, helping avoid costly grid upgrades.
• Facilitates plug‑and‑charge, V2G, and other advanced features when combined with standards like ISO 15118.
• Provides rich, standardized data for uptime reporting, compliance, and warranty tracking.
  
  

In regulated or subsidy‑driven markets, OCPP‑compliant systems are often required to prove session data, cause‑coded outages, and grid‑interaction behavior to government or funding bodies.

OCPP vs other EV protocols

• OCPP focuses on charger–backend communication (CPO‑side).
• OCPI focuses on roaming and cross‑network access (eMSP‑side).
• ISO 15118 focuses on vehicle‑to‑grid and plug‑and‑charge security and authentication.
  
  

In a mature EV ecosystem, these standards often work together: OCPP ensures the charger talks correctly to the CPMS, OCPI enables the driver to roam across networks, and ISO 15118 secures the vehicle‑side interaction.

OCPP and FieldEx

While OCPP handles the digital conversation between charger and CPMS, platforms like FieldEx sit underneath as the execution layer for physical operations. When an OCPP‑enabled CPMS detects a fault, FieldEx can:

• Automatically create a work order.
• Dispatch the right technician with the correct certifications.
• Track component replacements and link them back to the charger’s asset genealogy.
  
  

In short, OCPP connects the charger to the software; FieldEx connects the software to the technician.