esphome-docs/components/number/modbus_controller.rst

Modbus Controller Number
========================

.. seo::
    :description: Instructions for setting up a modbus_controller device sensor.
    :image: modbus_controller.png

The ``modbus_controller`` platform creates a Number from a modbus_controller.
When the Number is updated a modbus write command is created sent to the device.

Configuration variables:
------------------------

- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
- **name** (**Required**, string): The name of the sensor.
    - coil: coils are also called discrete outout. Coils are 1-bit registers (on/off values) that are used to control discrete outputs. Read and Write access
    - discrete_input: discrete input register (read only coil) are similar to coils but can only be read.
    - holding: Holding Registers - Holding registers are the most universal 16-bit register. Read and Write access
    - read: Read Input Registers - registers are 16-bit registers used for input, and may only be read
- **address**: (**Required**, int): start address of the first register in a range
- **value_type**: (**Required**): datatype of the mod_bus register data. The default data type for modbus is a 16 bit integer in big endian format (MSB first)
    - U_WORD (unsigned float from 1 register =16bit
    - S_WORD (signed float from one register)
    - U_DWORD (unsigned float from 2 registers = 32bit)
    - S_DWORD (unsigned float from 2 registers = 32bit)
    - U_DWORD_R (unsigend float from 2 registers low word first )
    - S_DWORD_R (sigend float from 2 registers low word first )
    - U_QWORD (unsigned float from 4 registers = 64bit
    - S_QWORD (signed float from 4 registers = 64bit
    - U_QWORD_R (unsigend float from 4 registers low word first )
    - S_QWORD_R (sigend float from 4 registers low word first )

- **skip_updates**: (*Optional*, integer): By default all sensors of of a modbus_controller are updated together. For data points that don't change very frequently updates can be skipped. A value of 5 would only update this sensor range in every 5th update cycle
  Note: The modbus_controller groups component by address ranges to reduce number of transactions. All compoents with the same address will be updated in one request. skip_updates applies for all components in the same range.
- **register_count**: (*Optional*): only required for uncommon response encodings
  The number of registers this data point spans. Default is 1
- **force_new_range**: (*Optional*, boolean): If possible sensors with sequential addresses are grouped together and requested in one range. Setting `foce_new_range: true` enforces the start of a new range at that address.
- **offset**: (*Optional*, int): only required for uncommon response encodings
    offset from start address in bytes. If more than one register is read a modbus read registers command this value is used to find the start of this datapoint relative to start address. The component calculates the size of the range based on offset and size of the value type
- **min_value** (*Optional*, float): The minimum value this number can be.
- **max_value** (*Optional*, float): The maximum value this number can be.
- **step** (*Optional*, float): The granularity with which the number can be set. Defaults to 1
- **lambda** (*Optional*, :ref:`lambda <config-lambda>`):
  Lambda to be evaluated every update interval to get the new value of the sensor.
- **write_lambda** (*Optional*, :ref:`lambda <config-lambda>`): Lambda called before send.
  Lambda is evaluated before the modbus write command is created.
- **multiply** (*Optional*, float): multiply the new value with this factor before sending the requests. Ignored if lambda is defined.


All other options from :ref:`Number <config-number>`.

Parameters passed into the lambda

- **x** (float): The parsed float value of the modbus data

- **data** (std::vector<uint8_t): vector containing the complete raw modbus response bytes for this sensor
      note: because the response contains data for all registers in the same range you have to use `data[item->offset]` to get the first response byte for your sensor.
- **item** (const pointer to a SensorItem derived object):  The sensor object itself.

Possible return values for the lambda:

 - ``return <FLOATING_POINT_NUMBER>;`` the new value for the sensor.
 - ``return NAN;`` if the state should be considered invalid to indicate an error (advanced).



**Parameters passed into write_lambda**

- **x** (float): The float value to be sent to the modbus device

- **payload** (`std::vector<uint16_t>&payload`): empty vector for the payload. The lamdba can add 16 bit raw modbus register words.
      note: because the response contains data for all registers in the same range you have to use `data[item->offset]` to get the first response byte for your sensor.
- **item** (const pointer to a SensorItem derived object):  The sensor object itself.

Possible return values for the lambda:

 - ``return <FLOATING_POINT_NUMBER>;`` the new value for the sensor.
 - ``return <anything>; and fill payload with data`` if the payload is added from the lambda then these 16 bit words will be sent
 - ``return {};`` if you don't want write the command to the device (or do it from the lambda).

**Example**

.. code-block:: yaml

    number:
      - platform: modbus_controller
        modbus_controller_id: epever
        id: battery_capacity_number
        name: "Battery Cap Number"
        address: 0x9001
        register_type: holding
        value_type: U_WORD
        lambda: "return  x * 1.0; "
        write_lambda: |-
          ESP_LOGD("main","Modbus Number incoming value = %f",x);
          uint16_t b_capacity = x ;
          payload.push_back(b_capacity);
          return x * 1.0 ;          
        ## multiply is ignored because lamdba is used
        multiply: 1.0


See Also
--------
- :doc:`/components/modbus_controller`
- :doc:`/components/sensor/modbus_controller`
- :doc:`/components/binary_sensor/modbus_controller`
- :doc:`/components/switch/modbus_controller`
- :doc:`/components/text_sensor/modbus_controller`
- :doc:`/components/output/modbus_controller`
- https://www.modbustools.com/modbus.html
- :ghedit:`Edit`