Grid-serving control

If your energy supplier/grid operator prescribes a ripple control receiver, please read the relevant section of our FAQ.

cFos Charging Manager on the Smart Meter Gateway (SMGW)

You can operate the cFos Charging Manager on the HAN interface of a smart meter gateway. According to BSI TR-03109-1, a Smart Meter Gateway provides a transparent interface from the HAN interface via the WAN interface to the network operator or energy supplier. This is regulated in HAF3 ( and must be configured accordingly by the smart meter gateway administrator (connection between EMT and CLS).

Operation on the Smart Meter Gateway requires a TLS certificate on the part of the cFos Charging Manager, which you can upload under "Configuration" in the Charging Manager and select for the Smart Meter Gateway.

You must also configure the IP address or URL under which the Smart Meter Gateway can be reached in the house network.

You can now select the following functions:

  1. The cFos Charging Manager uses the OCPP gateway to connect all configured EVSEs to the OCPP backend of the energy supplier via the Smart Meter Gateway. This enables the energy supplier to see the status of all EVSEs and to log charging processes and bill for the amount of energy consumed. The cFos Power Brain Wallboxs can also communicate in this way (even without a gateway) via the Smart Meter Gateway with the OCPP backend of the energy supplier.
  2. In the event of a power shortage, the energy supplier or grid operator can reduce the house connection power available to the cFos Charging Manager.
  3. The energy supplier can inform the cFos Charging Manager of the start and end of tariffs, which can then be taken into account by the EVSEs and users by means of charging rules.
  4. The grid operator or energy supplier can fully manage the customer installation as an administrator.

Functions 1. and 2. are enabled accordingly under "Configuration".

The HTTP API for network operators and energy suppliers can set and query Charging Manager variables by means of 2 calls. These variables can be taken into account when configuring the house connection power and the maximum EVSE power. Network operators and energy suppliers are free to define their own (manufacturer-independent) standards for how these variables are assigned.

Example: House connection power = 55000 * AVAIL / 100
The grid operator sets the variable AVAIL to values between 0-100 and can thus regulate the power of the customer system down in percentage steps.

Example: TARIF
The energy supplier sets the variable TARIF to 0 or 1 and informs the system by means of 0 that the "normal" tariff now applies and by means of 1 that a reduced tariff now applies. The users of the system can then create charging rules that allow them to charge the car only at certain tariffs or charge at a lower charging power at certain tariffs.

Figure Grid-serving charging management


Set a variable

GET /cnf?cmd=set_cm_vars&name=n&val=v&clear=c
n is the name of the variable, v is its value.
clear is optional, with c=1 all existing variables are deleted before resetting.

curl -i -X GET --user admin:1234abcd 'http://localhost/cnf?cmd=set_cm_vars&name=var3&val=123' Linux
curl -i -X GET --user admin:1234abcd "http://localhost/cnf?cmd=set_cm_vars&name=var3&val=123" Windows

Set all variables

POST /cnf?cmd=set_cm_vars&clear=1
The POST body contains a JSON object with the names and values of the variables, e.g.

{"vars": [{ "name": "var1", "expr": 1.5 }], { "name": "var2", "expr": 2 }] }
Delete all variables and set var1 to 1.5, var2 to 2 .

curl -i -X POST -d '{ "vars": [{ "name": "tarif", "expr": 1 }, { "name": "PWR", "expr": 70 }] }' --user admin:1234abcd 'http://localhost/cnf?cmd=set_cm_vars' Linux
curl -i -X POST -d "{ \"vars\": [{ \"name\": \"tarif\", \"expr\": 1 }, { \"name\": \"PWR\", \"expr\": 70 }] }" --user admin:1234abcd "http://localhost/cnf?cmd=set_cm_vars" Windows

Read all variables

GET /cnf?cmd=get_cm_vars
Returns a JSON object matching set_cm_vars with all variables, their formulas (or constants) and their currently calculated values.

curl -i -X GET --user admin:1234abcd 'http://localhost/cnf?cmd=get_cm_vars Linux
curl -i -X GET --user admin:1234abcd "http://localhost/cnf?cmd=get_cm_vars Windows

This API can be accessed via the Smart Meter Gateway without further authentication, as the Smart Meter Gateway already takes care of this by defining the connections and authentication by means of certificates. This API can be used from the home network by means of an administrator password.