# Custom Modbus TCP and Remote Values

Part of the [compatibility overview](/integrations/compatibility), which lists every selectable Mains type.

* `Custom Modbus TCP` reads any Modbus TCP meter with a register map stored
  on the station. The map is prepared by eCharge support for the specific
  meter; contact support with the meter's Modbus register documentation.
  Battery registers cannot be used with this type; it delivers grid values
  only.
* `Remote Values` takes the grid values from an external system that writes
  them to the station over the REST API, and needs no meter at all. Battery
  power and state of charge can be pushed as well. Values
  must arrive at least every 10 seconds; otherwise the station treats the
  meter as unavailable and regulates with 0 W. Per-phase powers for L2 and
  L3 are currently not taken over from the pushed values. Ask eCharge
  support for the field format.