Overview Wallbox general

This function block controls a manufacturer-independent wallbox in such a way that the PV surplus is charged with priority. In contrast to the block Wallbox KEBA, this block does not communicate with the charging station itself: plug status and current charging power are read in via inputs, the calculated charging current setpoint and the enable of surplus charging are output via outputs. This allows the control to be connected to any wallbox (e.g. via Modbus or KNX).

In addition, an energy meter for the current session and for the total energy is formed from the charging power read in. The total meter is stored permanently.


Inputs

FG Enable Optional enable. When the input is 1, the control is enabled. This input can be used to switch the control on and off in automatic mode without having to change the operating mode.

If the input is not connected, the control is always enabled.
BA
 Operating mode*
 Operating mode:
  • 0=Automatic: surplus control
  • 1=Manual: manual charging with the current value from the input charging current manual A.
  • 2=Off: charging off.
ST Plug status* Plug status of the wallbox. In automatic mode, charging only occurs when the plug status is not equal to 0. A change of the plug status (e.g. new plug-in) starts a new charging session and resets the session meter.

If the input is not connected, the plug is assumed to be plugged in.
PU
 Surplus W*
 PV surplus in W. The input must not be limited to 0; both positive and negative values must arrive at the input so that the control can react correctly. The parameter Surplus type can be used to set whether positive or negative means surplus.
WL Wallbox power kW* Current charging power of the wallbox in kW. This value is used to form the energy meter by integration. In automatic mode the charging current is only increased when more than 0.5 kW actually flows; otherwise it is set to the minimum charging current. This keeps the setpoint from ramping up into nothing while the vehicle is not charging yet.

If the input is not linked, the charging power counts as unknown and control works as without a power measurement. The real measurement has to be connected: a fixed value defeats this check and in addition falsifies the energy meters.
LM
 Charging current manual A
 Default charging current for the operating mode Manual. The value is limited to charging current minimum and charging current maximum.
LE Session kWh setpoint Charging energy for the current charging session. With a value > 0, charging is stopped when this energy has been charged. After the stop, the operating mode is set to Off and this input is reset to 0.
RS Reset meter With a rising edge (0 to non-zero), the total meter and the session meter are reset to 0.

Outputs
FU
 Enable surplus charging
 Output is 1 when surplus charging is active (control enabled and operating mode Automatic).
LS Charging current setpoint A Calculated charging current setpoint that is sent to the wallbox (e.g. via Modbus). The value is limited to charging current minimum and charging current maximum.
EA Meter session kWh Energy charged in the current charging session. Is set to 0 at the start of a new session (change of plug status or operating mode, reset meter).
EG Meter total kWh Total energy charged. Is formed by integrating the input Wallbox power kW over time and stored permanently.

Parameters
Surplus type
  • Surplus positive: surplus when input is positive
  • Surplus negative: surplus when input is negative
Start at surplus Minimum surplus at which the control starts. Value is always positive.
Control time on Time for control on. The surplus must be above "Start at surplus" for at least this time for the control to start.
Control time off Time for control off. If the surplus is below 0 for this time (drawing from the grid), the control is switched off.
Surplus minimum The control regulates to this value; this surplus always remains.  Value is always positive.
Gain P
 Speed of the control; with a higher value the output reacts faster to a change at the input.
Charging current minimum
 Minimum charging current in A
Charging current maximum
 Maximum charging current in A


See also common parameters of all function blocks.