home-assistant.io/source/_integrations/modbus.markdown

title, description, ha_category, ha_release, ha_iot_class, ha_codeowners, ha_domain, ha_platforms, ha_quality_scale, ha_integration_type

title	description	ha_category	ha_release	ha_iot_class	ha_codeowners	ha_domain	ha_platforms	ha_quality_scale	ha_integration_type
Modbus	Instructions on how to integrate Modbus and platforms.	Hub	pre 0.7	Local Polling	@adamchengtkc @janiversen @vzahradnik	modbus	binary_sensor climate cover fan light sensor switch	gold	integration

Modbus is a serial communication protocol to control PLCs (Programmable Logic Controller) and RTUs (Remote Terminal Unit). The integration adheres strictly to the protocol specification. Modbus supports all devices adhering to the Modbus standard. The communication between the device(s) can be serial (rs-485), TCP, or UDP connections. The Modbus integration allows multiple communications e.g. serial combined with TCP or different TCP connected devices.

Configuring Modbus

First, you define how to communicate with your Modbus devices and after that you define the information being exchanged. The Modbus integration allows you to use multiple connections.

Configuring Modbus common parameters

Part of the configuration is common for all types of communication. Add the following to your configuration.yaml file:

modbus:
  - name: "hub1"
    close_comm_on_error: true
    delay: 5
    timeout: 5
    type: tcp

{% configuration %} close_comm_on_error: description: Determines if the device connection is closed when an error occurs, default is true. Some serial-rs485 adapters deliver garble when opened, this leads to a disconnect and a new connect, which can continue. If in a running communication the debug log contains a message from pymodbus, with the text "cleaning....", then try this parameter. required: false default: true type: boolean delay: description: "Time to delay sending messages in seconds after connecting. Some Modbus devices need a delay of typically 1-2 seconds after established connection to prepare the communication. If a device does not respond to messages after connecting, this parameter might help. Remark: the delay is solely between connect and the first message." required: false default: 0 type: integer message_wait_milliseconds: description: Time to wait in milliseconds between requests. required: false default: 30 for serial connection, 0 for everything else. type: integer name: description: Name for this hub. Must be unique, so it is required when setting up multiple instances. required: false default: "modbus_hub" type: string retries: description: Number of times to retry a request. required: false default: 3 type: integer retry_on_empty: description: Retry request, when receiving and empty message. required: false default: false type: boolean timeout: description: "Timeout while waiting for a response in seconds." required: false default: 5 type: integer type: description: Type of communication. Possible values are tcp Modbus messages with Modbus TCP frame on TCP/IP, udp Modbus messages with Modbus TCP frame on UDP, rtuovertcp Modbus messages with a wrapper TCP/IP simulating a serial line, serial Modbus serial (RS485). required: true type: string {% endconfiguration %}

Configuring network connection

For a network (type: tcp/udp/rtuovertcp) connection, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry for a TCP connection
modbus:
  - name: "hub1"
    type: tcp
    host: IP_ADDRESS
    port: 502

{% configuration %} host: description: The IP address of your Modbus device, e.g., 192.168.1.1. required: true type: string port: description: The network port for the communication. required: true type: integer type: description: "Type of the connection to Modbus, needs to be tcp or udp or rtuovertcp for this setup." required: true type: string {% endconfiguration %}

Configuring serial connection

For a serial connection, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry for a serial connection
modbus:
  - name: hub1
    type: serial
    baudrate: 9600
    bytesize: 8
    method: rtu
    parity: E
    port: /dev/ttyUSB0
    stopbits: 1

{% configuration %} baudrate: description: The speed for the serial connection. required: true type: integer bytesize: description: "The bytesize for the serial connection; can be 5, 6, 7 or 8." required: true type: integer method: description: "Method of the connection to Modbus, either rtu or ascii." required: true type: string parity: description: "The parity for the serial connection; can be E, O or N." required: true type: string port: description: The port where your Modbus device is connected to your Home Assistant host. required: true type: string stopbits: description: "The stopbits for the serial connection, either 1 or 2." required: true type: integer type: description: "Type of the connection to Modbus, needs to be serial for this setup." required: true type: string {% endconfiguration %}

Configuring multiple connections

Multiple connections are possible with identical/different type:.

# Example configuration.yaml entry for multiple TCP connections
modbus:
  - type: tcp
    host: IP_ADDRESS_1
    port: 2020
    name: "hub1"

  - type: udp
    host: IP_ADDRESS_2
    port: 501
    name: hub2

Remark: name:is required for multiple connections, because it needs to be unique.

Modbus services

The Modbus integration provides two generic write services in addition to the platform-specific services.

Service	Description
modbus.write_register	Write register or registers
modbus.write_coil	Write coil or coils

Description:

Attribute	Description
hub	Hub name (defaults to 'modbus_hub' when omitted)
unit	Slave address (0-255), alternative to slave
slave	Slave address (0-255), alternative to unit
address	Address of the Register (e.g. 138)
value	(write_register) A single value or an array of 16-bit values. Single value will call modbus function code 0x06. Array will call modbus function code 0x10. Values might need reverse ordering. E.g., to set 0x0004 you might need to set [4,0], this depend on the byte order of your CPU
state	(write_coil) A single boolean or an array of booleans. Single boolean will call modbus function code 0x05. Array will call modbus function code 0x0F

The Modbus integration also provides communication stop/restart services. These services will not do any reconfiguring, but simply stop/start the modbus communication layer.

Service	Description
modbus.stop	Stop communication
modbus.restart	Restart communication (Stop first if running)

Description:

Attribute	Description
hub	Hub name (defaults to 'modbus_hub' when omitted)

Example: writing a float32 type register

To write a float32 datatype register use network format like 10.0 == 0x41200000 (network order float hexadecimal).

service: modbus.write_register
data:
  address: <target register address>
  unit: <target slave address>
  hub: <hub name>
  value: [0x4120, 0x0000]

configure Modbus platforms

Modbus platform entities are configured within the Modbus configuration.

Configuring platform common parameters

All modbus platforms share a set of common parameters.

# Example configuration.yaml entry for platform common parameters
modbus:
  - type: tcp
    host: IP_ADDRESS_1
    port: 2020
    name: "hub1"
    sensors:
      - name: sensor1
        scan_interval: 999
        slave: 0

{% configuration %} lazy_error_count: description: Number of messages with error received before setting entity to unavailable. This parameter can be used to prevent spontaneous errors to ruin statistic graphs. required: false type: integer default: 0 name: description: Name for the platform entity which must be unique within the platform. required: true type: string scan_interval: description: Defines the update interval of the entity in seconds, if scan_interval = 0 polling is stopped. Entities are unavailable until the first response is received, except for entities with scan_interval = 0, these entities are available from startup. required: false type: integer default: 15 slave: description: The number of the slave. required: false type: integer default: 0 unique_id: description: An ID that uniquely identifies this sensor. Slaves will be given a unique_id of <<unique_id>>_<<slave_index>>. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Configuring data_type and struct

Climate and Sensor share setup of data_type and struct.

# Example configuration.yaml entry for platform common parameters
modbus:
  - type: tcp
    host: IP_ADDRESS_1
    port: 2020
    name: "hub1"
    sensors:
      - name: sensor1
        data_type: int

{% configuration %} data_type: description: Response representation (int8, int16, int32, int64, uint8, uint16, uint32, uint64, float16, float32, float64, string). int/uintare silently converted to int16/uint16. required: false type: string default: int16 offset: description: Final offset (output = scale * value + offset). required: false type: float default: 0 precision: description: Number of valid decimals. required: false type: integer default: 0 scale: description: Scale factor (output = scale * value + offset). required: false type: float default: 1 structure: description: "If data_type is custom specified a double-quoted Python struct is expected here, to format the string to unpack the value. See Python documentation for details. Example: >i." required: false type: string default: ">f" swap: description: "Swap the order of bytes/words, options are none, byte, word, word_byte." required: false default: none type: string unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Configuring platform binary sensor

The Modbus binary sensor allows you to gather data from coils which as per standard have state ON/OFF.

To use your Modbus binary sensors in your installation, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry for binary_sensor configuration
modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    binary_sensors:
      - name: "binary_sensor1"
        address: 100
        scan_interval: 20
        slave: 1
      - name: "binary_sensor2"
        address: 110
        device_class: door
        input_type: discrete_input
      - name: "binary_sensor3"
        address: 120
        slave: 2
        device_class: running
        scan_interval: 10
        input_type: input

{% configuration %} binary_sensors: description: A list of all binary_sensors available in this modbus instance, omit if there are no binary_sensors. required: false type: [map] keys: address: description: Address of the Register. required: true type: integer device_class: description: The type/class to be used for the UI (e.g. "door"). required: false type: string input_type: description: type of address (discrete_input/coil/holding/input) required: false default: coil type: string unique_id: description: An ID that uniquely identifies this sensor. Slaves will be given a unique_id of <<unique_id>>_<<slave_index>>. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string slave_count: description: Generates x-1 slave binary sensors, allowing read of multiple coils with a single read messsage. required: false type: integer

{% endconfiguration %}

Configuring platform climate

The Modbus climate platform allows you to monitor your thermostat as well as set a target temperature.

To use your Modbus thermostat in your installation, add the following to your configuration.yaml file, in addition to the common parameters and response regresentation:

# Example configuration.yaml entry
modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    climates:
      - name: "Watlow F4T"
        address: 27586
        input_type: holding
        count: 1
        data_type: custom
        max_temp: 35
        min_temp: 15
        offset: 0
        precision: 1
        scale: 0.1
        max_temp: 30
        structure: ">f"
        target_temp_register: 2782
        temp_step: 1
        temperature_unit: C
      - name: "Bedroom Air Condition"
        address: 10
        target_temp_register: 10
        hvac_mode_register:
          address: 11
          values:
            state_auto: 0
            state_cool: 1
            state_heat: 2
            state_fan_only: 3
            state_dry: 4
            state_off: 5
        hvac_onoff_register: 11

{% details "Previous configuration format" %}

The configuration format of hvac_mode_register has changed. The old format uses keys such as off, auto, cool instead of state_off, state_auto and state_cool that is currently used. The old keys should no longer be used and is deprecated.

{% enddetails %}

{% configuration %} climates: description: A list of all climates available in this modbus instance. required: false type: [map] keys: address: description: Register address for current temperature (process value). required: true type: integer count: description: Number of registers to read. required: false type: integer default: 1 or calculated if data_type is not struct. input_type: description: Modbus register type (holding, input) for current temperature. required: false type: string default: holding max_temp: description: Maximum setpoint temperature. required: false type: integer default: 35 min_temp: description: Minimum setpoint temperature. required: false type: integer default: 5 target_temp_register: description: Register address for target temperature (Setpoint). required: true type: integer temp_step: description: The supported step size a target temperature can be increased/decreased. required: false type: float default: 0.5 temperature_unit: description: Temperature unit reported by the current_temp_register. C or F required: false type: string default: C hvac_mode_register: description: Definition of a register holding and controlling an HVAC mode required: false type: [map] keys: address: description: The address of the HVAC mode register. required: true type: integer values: description: A mapping between the register values and HVAC modes required: true type: [map] keys: state_off: description: The register value corresponding to HVAC Off mode. required: false type: integer state_heat: description: The register value corresponding to HVAC Heat mode. required: false type: integer state_cool: description: The register value corresponding to HVAC Cool mode. required: false type: integer state_auto: description: The register value corresponding to HVAC Auto mode. required: false type: integer state_dry: description: The register value corresponding to HVAC Dry mode. required: false type: integer state_fan_only: description: The register value corresponding to HVAC Fan only mode. required: false type: integer state_heat_cool: description: The register value corresponding to HVAC Heat/Cool mode. required: false type: integer hvac_onoff_register: description: Address of a register holding and controlling the On/Off state of the climate device. When zero is read from this register, the HVAC state is set to Off, otherwise the hvac_mode_register dictates the state of the HVAC. If no such register is defined, it defaults to Auto. When the HVAC mode is set to Off, the value 0 is written to the register, otherwise the value 1 is written. required: false type: integer unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Service modbus.set-temperature

Service	Description
set_temperature	Set Temperature. Requires value to be passed in, which is the desired target temperature. value should be in the same type as data_type

Service modbus.set_hvac_mode

Service	Description
set_hvac_mode	Set HVAC mode. Requires value to be passed in, which is the desired mode. value should be a valid HVAC mode. A mapping between the desired state and the value to be written to the HVAC mode register must exist. Calling this service will also set the On/Off register to an appropriate value, if such a register is defined.

Configuring platform cover

The modbus cover platform allows you to control covers (such as blinds, a roller shutter, or a garage door).

At the moment, platform cover support the opening and closing of a cover. You can control your covers either using coils or holding registers.

Cover that uses input_type: coil is not able to determine intermediary states such as opening and closing. Coil stores only two states — "0" means cover closed, and "1" implies cover open. To allow detecting intermediary states, there is an optional status_register attribute. It will enable you to write your command (e.g., to open a cover) into a coil, and read current cover status back through the register. Additionally, you can specify values for state_open, state_opening, state_closed, and state_closing attributes. These will be matched with the value read from the status_register.

If your cover uses ìnput_type: holding(default) to send commands, it can also read the intermediary states. To adjust which value represents what state, you can fine-tune the optional state attributes, likestate_open`. These optional state values are also used for specifying values written into the register. If you specify an optional status_register attribute, cover states will be read from status_register instead of the register used for sending commands.

To use Modbus covers in your installation, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry
modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    covers:
      - name: Door1
        device_class: door
        input_type: coil
        address: 117
        state_open: 1
        state_opening: 2
        state_closed: 0
        state_closing: 3
        status_register: 119
        status_register_type: holding
      - name: "Door2"
        address: 118

{% configuration %} covers: description: The array contains a list of all your Modbus covers. required: true type: map keys: address: description: Address of coil / register. required: true type: integer device_class: description: The type/class of the cover to set the icon in the frontend. required: false type: device_class default: None input_type: description: Modbus register type (holding, input), default holding. default: holding required: false type: string state_open: description: A value in status_register or register representing an open cover. If your configuration uses the register attribute, this value will be written into the holding register to open the cover. required: false default: 1 type: integer state_closed: description: A value in status_register or register representing a closed cover. If your configuration uses the register attribute, this value will be written into the holding register to close the cover. required: false default: 0 type: integer state_opening: description: A value in status_register or register representing an opening cover. Note that this state should be also supported on your connected Modbus cover. If it won't report the state, this state won't be detected. required: false default: 2 type: integer state_closing: description: A value in status_register or register representing a closing cover. Note that this state should be also supported on your connected Modbus cover. If it won't reeport the state, this state won't be detected. required: false default: 3 type: integer status_register: description: An address of a register, from which all the cover states will be read. If you specified register attribute, and not status_register attribute, your main register will also be used as a status register. required: false type: integer status_register_type: description: Modbus register type (holding, input), default holding. required: false type: string unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Example: Modbus cover controlled by a coil

This example shows a configuration for a Modbus cover controlled using a coil. Intermediary states like opening/closing are not supported. The cover state is polled from Modbus every 10 seconds.

modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    covers:
      - name: Door1
        slave: 1
        coil: 1
        device_class: door
        scan_interval: 10
      - name: Door2
        slave: 2
        coil: 2
        device_class: door
        scan_interval: 10

Example: Modbus cover controlled by a coil, its state is read from the register

This example shows a configuration for a Modbus cover controlled using a coil. Actual cover state is read from the status_register. We've also specified register values to match with the states open/opening/closed/closing. The cover state is polled from Modbus every 10 seconds.

modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    covers:
      - name: Door1
        slave: 1
        device_class: door
        scan_interval: 10
        coil: 1
        status_register: 1
        status_register_type: input
        state_opening: 1
        state_open: 2
        state_closing: 3
        state_closed: 4

Example: Modbus cover controlled by a holding register

This example shows a configuration for a Modbus cover controlled using a holding register, from which we also read current cover state. We've also specified register values to match with the states open/opening/closed/closing. The cover state is polled from Modbus every 10 seconds.

modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    covers:
      - name: Door1
        slave: 1
        device_class: door
        scan_interval: 10
        register: 1
        state_opening: 1
        state_open: 2
        state_closing: 3
        state_closed: 4

Example: Modbus cover controlled by a holding register, its state is read from the status register

This example shows a configuration for a Modbus cover controlled using a holding register. However, cover state is read from a status_register. In this case, we've specified only values for state_open and state_closed, for the rest, default values are used. The cover state is polled from Modbus every 10 seconds.

modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502

    covers:
      - name: Door1
        slave: 1
        device_class: door
        scan_interval: 10
        register: 1
        status_register: 2
        register_type: holding
        state_open: 1
        state_closed: 0

Configuring platform fan

The modbus fan platform allows you to control Modbus coils or registers.

To use your Modbus fans in your installation, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry
modbus:
  - type: tcp
    host: IP_ADDRESS
    port: 502
    fans:
      - name: "Fan1"
        address: 13
        write_type: coil
      - name: "Fan2"
        slave: 2
        address: 14
        write_type: coil
        verify:
      - name: "Register1"
        address: 11
        command_on: 1
        command_off: 0
        verify:
            input_type: holding
            address: 127
            state_on: 25
            state_off: 1

{% configuration %} fans: description: The array contains a list of all your Modbus fans. required: true type: map keys: address: description: Coil number or register. required: true type: integer command_on: description: Value to write to turn on the fan. required: false default: 0x01 type: integer command_off: description: Value to write to turn off the fan. required: false default: 0x00 type: integer write_type: description: Type of address (holding/coil or holdings/coils for array call). required: false default: holding type: string name: description: Name of the fan. required: true type: string verify: description: Read from Modbus device to verify fan. If used without attributes it uses the toggle register configuration. If omitted no verification is done, but the state of the fan is set with each toggle. required: false type: map keys: address: description: Address to read from. required: false default: write address type: integer delay: description: delay between write and verify. required: false default: 0 type: integer input_type: description: Type of address (holding/coil/discrete/input). required: false default: write_type type: integer state_on: description: Value when the fan is on. required: false default: same as command_on type: integer state_off: description: Value when the fan is off. required: false default: same as command_off type: integer unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Configuring platform light

The modbus light platform allows you to control Modbus coils or registers.

To use your Modbus lights in your installation, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry
modbus:
  - type: tcp
    host: IP_ADDRESS
    port: 502
    lights:
      - name: "light1"
        address: 13
        write_type: coil
      - name: "light2"
        slave: 2
        address: 14
        write_type: coil
        verify:
      - name: "Register1"
        address: 11
        command_on: 1
        command_off: 0
        verify:
            input_type: holding
            address: 127
            state_on: 25
            state_off: 1

{% configuration %} lights: description: The array contains a list of all your Modbus lights. required: true type: map keys: address: description: Coil number or register. required: true type: integer command_on: description: Value to write to turn on the fan. required: false default: 0x01 type: integer command_off: description: Value to write to turn off the light. required: false default: 0x00 type: integer write_type: description: Type of address (holding/coil or holdings/coils for array call). required: false default: holding type: string verify: description: Read from Modbus device to verify the light. If used without attributes it uses the toggle register configuration. If omitted no verification is done, but the state of the light is set with each toggle. required: false type: map keys: address: description: Address to read from. required: false default: write address type: integer delay: description: delay between write and verify. required: false default: 0 type: integer input_type: description: Type of address (holding/coil/discrete/input). required: false default: write_type type: integer state_on: description: Value when the light is on. required: false default: same as command_on type: integer state_off: description: Value when the light is off. required: false default: same as command_off type: integer unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Configuring platform sensor

The modbus sensor allows you to gather data from Modbus registers.

To use your Modbus sensors in your installation, add the following to your configuration.yaml file, in addition to the common parameters and response regresentation:

# Example configuration.yaml entry
modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    sensors:
      - name: Sensor1
        unit_of_measurement: °C
        slave: 1
        address: 100
      - name: Sensor2
        unit_of_measurement: mg
        address: 110
        count: 2
      - name: Sensor3
        unit_of_measurement: °C
        slave: 1
        address: 120
        input_type: input
        data_type: float
        scale: 0.01
        offset: -273.16
        precision: 2

{% configuration %} sensors: description: The array contains a list of all your Modbus sensors. required: true type: map keys: address: description: Register number. required: true type: integer count: description: Number of registers to read. required: false type: integer default: 1 or calculated if data_type is not struct. device_class: description: The type/class of the sensor to set the icon in the frontend. required: false type: device_class default: None input_type: description: Modbus register type (holding, input), default holding. required: false type: string name: description: Name of the sensor. required: true type: string scan_interval: description: Defines the update interval of the sensor in seconds. required: false type: integer default: 15 slave: description: The number of the slave (Optional for tcp and upd Modbus). required: true type: integer unit_of_measurement: description: Unit to attach to value. required: false type: string min_value: description: The minimum allowed value of a sensor. If value < min_value --> min_value. Can be float or integer required: false type: float max_value: description: The maximum allowed value of a sensor. If value > max_value --> max_value. Can be float or integer required: false type: float zero_suppress: description: Suppress values close to zero. If -zero_suppress <= value <= +zero_suppress --> 0. Can be float or integer required: false type: float state_class: description: The state_class of the sensor. required: false type: string unique_id: description: An ID that uniquely identifies this sensor. Slaves will be given a unique_id of <<unique_id>>_<<slave_index>>. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string slave_count: description: Generates x-1 slave sensors, allowing read of multiple registers with a single read messsage. required: false type: integer {% endconfiguration %}

If you specify scale or offset as floating point values, double precision floating point arithmetic will be used to calculate final value. This can cause loss of precision for values that are larger than 2^53.

Full example

Example temperature sensor with a default scan interval:

modbus:
  - name: hub1
    type: tcp
    host: IP_ADDRESS
    port: 502
    sensors:
      - name: Room_1
        slave: 10
        address: 0
        input_type: holding
        unit_of_measurement: °C
        state_class: measurement
        count: 1
        scale: 0.1
        offset: 0
        precision: 1
        data_type: integer

Configuring platform switch

The modbus switch platform allows you to control Modbus coils or registers.

To use your Modbus switches in your installation, add the following to your configuration.yaml file, in addition to the common parameters:

# Example configuration.yaml entry
modbus:
  - type: tcp
    host: IP_ADDRESS
    port: 502
    switches:
      - name: Switch1
        address: 13
        write_type: coil
      - name: Switch2
        slave: 2
        address: 14
        write_type: coil
        verify:
      - name: Register1
        address: 11
        command_on: 1
        command_off: 0
        verify:
            input_type: holding
            address: 127
            state_on: 25
            state_off: 1

{% configuration %} switches: description: The array contains a list of all your Modbus switches. required: true type: map keys: address: description: Coil number or register required: true type: integer command_on: description: Value to write to turn on the switch. required: false default: 0x01 type: integer command_off: description: Value to write to turn off the switch. required: false default: 0x00 type: integer write_type: description: type of address (holding/coil or holdings/coils for array call) required: false default: holding type: string verify: description: Read from modbus device to verify switch. If used without attributes it uses the toggle register configuration. If omitted no verification is done, but the state of the switch is set with each toggle. required: false type: map keys: address: description: Address to read from. required: false default: write address type: integer delay: description: delay between write and verify. required: false default: 0 type: integer input_type: description: type of address (holding/coil/discrete/input or holdings/coils for array call) required: false default: write_type type: integer state_on: description: value when switch is on. required: false default: same as command_on type: integer state_off: description: value when switch is off. required: false default: same as command_off type: integer unique_id: description: An ID that uniquely identifies this sensor. If two sensors have the same unique ID, Home Assistant will raise an exception. required: false type: string {% endconfiguration %}

Opening an issue

When opening an issue, please add your current configuration (or a scaled down version), with at least:

• the Modbus configuration lines
• the entity (sensor, etc.) lines

In order for the developers better to identify the problem, please add the following lines to configuration.yaml:

logger:
  default: warning
  logs:
    homeassistant.components.modbus: debug
    pymodbus: debug

and restart Home Assistant, reproduce the problem, and include the log in the issue.

Building on top of Modbus

• Modbus Binary Sensor
• Modbus Climate
• Modbus Cover
• Modbus Fan
• Modbus Sensor
• Modbus Switch