OCPP connects any charging station to any software.
Where the standard came from, which versions matter and what it means in daily operation.
What OCPP is and where it came from
OCPP is the shared language between a charging station and the software that runs it.
A charging station has to be able to ask whether a card may charge. It has to report how much energy has flowed. It has to be able to say that its plug is stuck. All three need a language that each side understands. That language is OCPP.
Before the standard, every manufacturer brought its own. Buying stations from two makes meant two portals, two contracts and two logins. A single view across the whole estate existed nowhere. Changing manufacturer meant replacing the entire installation.
OCPP started in 2009 at ElaadNL, the Dutch grid operators’ joint venture. In 2014 stewardship passed to the Open Charge Alliance, an open association of manufacturers and operators. OCPP 1.6 followed in 2015 and remains the version almost every wallbox on sale can speak. The standard is public and carries no licence fee.
The standard describes a manageable set of messages. A station registers at start-up, sends a regular sign of life, asks about cards, reports the beginning and end of a charging session and delivers meter readings. The software answers, and it can start a session, reset the station or release the plug on its own. Each message has a fixed shape, and each one gets a reply.
OCPP 1.6 comes in two transports. Version 1.6-J carries the messages as JSON and is the one in common use. The older 1.6-S uses SOAP and is fading out. A wallbox bought today will almost always speak 1.6-J. The successor, OCPP 2.0.1, appeared in 2020 and is spreading slowly.
What the standard covers
Three jobs account for most of what happens day to day.
Register and report
The station says who it is at start-up, then checks back in at a fixed interval.
Read more →Ask and answer
Before every session the station asks whether this card may charge here.
Read more →Count and deliver
At the start, during and at the end the station sends its meter readings.
Read more →
What this means for you
A station that speaks OCPP can be connected to any software that speaks it too. The manufacturer becomes interchangeable. Before buying, two questions pay off: which version does the station support, and can the server address be set freely? Two yeses keep the installation open for whatever comes next.
Do your stations speak OCPP?
Tell us the make and the number. We will tell you what can be connected.