Operate cFos Charging Manager with Volkszähler/vzlogger

In the case of Volkszähler meters, data can be read from some of the network operator's meters using a D0 read head. This can then be made available to the cFos Charging Manager with vzlogger.
vzlogger delivers a JSON file with current counter values. An example file can be found here: vzlogger-out.json (as a ZIP archive).

In order to be able to read these with the cFos Charging Manager, you have to create an individually adapted meter definition file and then upload it as a user-defined meter. An example file can be found here: cfos-meter-vzlogger-bi.json (as a ZIP archive).
vzlogger creates an element in the "data" array for each counter value. The values are then tuple[0][1].

The order in which the counter values appear in the JSON file depends on the order in which they were configured in vzlogger. If you operate a meter with a positive and negative sign of the power when you purchase electricity (positive) and feed-in (negative), you have to install the following patch for vzlogger and compile vzlogger accordingly: https://github.com/volkszaehler/vzlogger/pull/476.

Many thanks to Joachim B. for explaining and providing the sample files.