OpenEMS Modbus-API

License notice:

For active battery control on FENECON FEMS systems, a commercial license (FEMS App Modbus/TCP Write Access) is required.

FEMS documentation:

FEMS App Modbus/TCP Read Access: docs.fenecon.de
FEMS App Modbus/TCP Write Access: docs.fenecon.de

OpenEMS documentation:

OpenEMS Edge Api Modbus Controller: openems.github.io

Supported features

Battery control: External control of home battery charging and discharging via evcc.

Usage areas

Grid meter
Solar production
Battery

Parameters

Name	Description	Value	Level
`id`	Modbus ID Default: `1`	int	required
`host`	IP address or hostname Example: `192.0.2.2`		required
`port`	Port Default: `502`	int	required
`battery`	controls battery component active battery control (Modbus/TCP Write Access) Default: `false`		optional
`capacity` [kWh]	Battery capacity Example: `50`		optional
`minsoc` [%]	Minimum charge Lower limit when discharging the battery in normal operation Example: `25`		optional
`maxsoc` [%]	Maximum charge Upper limit when charging the battery from the grid Example: `95`		optional
`grid_power_register`	Modbus register for grid power GridActivePower (W) Default: `315`		advanced
`grid_energy_register`	Modbus register for grid import energy GridBuyActiveEnergy (Wh) Default: `359`		advanced
`pv_power_register`	Modbus register for PV power ProductionActivePower (W) Default: `327`		advanced
`pv_energy_register`	Modbus register for PV energy ProductionActiveEnergy (Wh) Default: `367`		advanced
`maxacpower` [W]	Maximum AC power of the hybrid inverter Default: `0` Example: `5000`		advanced
`battery_power_register`	Modbus register for battery power EssDischargePower (W) Default: `415`		advanced
`battery_soc_register`	Modbus register for state of charge SoC (%) Default: `302`		advanced
`battery_set_register`	Modbus register for charge power SetActivePowerLessOrEquals (W) Default: `710`		advanced
`watchdog`	battery control API timeout Default: `60s`		advanced
`maxchargepower` [W]	Maximum charge power For forced charging of the battery.		advanced
`maxdischargepower` [W]	Maximum discharge power Maximum discharge power of the storage.		advanced

Configuration example for evcc.yaml

If you don't want to configure via the UI, you can alternatively use this YAML block.

Grid meter Solar production Battery

meters:
    - name: my_grid
      type: template
      template: openems-modbus
      usage: grid

      # Modbus TCP
      modbus: tcpip
      id: 1
      host:  # Hostname
      port: 502 # Port
      grid_power_register: 315 # Modbus register for grid power, GridActivePower (W) (optional)
      grid_energy_register: 359 # Modbus register for grid import energy, GridBuyActiveEnergy (Wh) (optional)

meters:
    - name: my_pv
      type: template
      template: openems-modbus
      usage: pv

      # Modbus TCP
      modbus: tcpip
      id: 1
      host:  # Hostname
      port: 502 # Port
      pv_power_register: 327 # Modbus register for PV power, ProductionActivePower (W) (optional)
      pv_energy_register: 367 # Modbus register for PV energy, ProductionActiveEnergy (Wh) (optional)
      maxacpower: 0 # Maximum AC power of the hybrid inverter (W), optional

meters:
    - name: my_battery
      type: template
      template: openems-modbus
      usage: battery

      # Modbus TCP
      modbus: tcpip
      id: 1
      host:  # Hostname
      port: 502 # Port
      battery: false # controls battery component, active battery control (Modbus/TCP Write Access) (optional)
      capacity: 50 # Battery capacity (kWh), optional
      minsoc: 25 # Minimum charge (%), Lower limit when discharging the battery in normal operation (optional)
      maxsoc: 95 # Maximum charge (%), Upper limit when charging the battery from the grid (optional)
      battery_power_register: 415 # Modbus register for battery power, EssDischargePower (W) (optional)
      battery_soc_register: 302 # Modbus register for state of charge, SoC (%) (optional)
      battery_set_register: 710 # Modbus register for charge power, SetActivePowerLessOrEquals (W) (optional)
      watchdog: 60s # battery control API timeout, optional
      maxchargepower: # Maximum charge power (W), For forced charging of the battery. (optional)
      maxdischargepower: # Maximum discharge power (W), Maximum discharge power of the storage. (optional)