.. py:currentmodule:: modbus

ModbusRTUSlave
==============

.. include:: ../refs/software.modbus.rtu.slave.ref

ModbusRTUSlave implements the Modbus RTU slave. ModbusRTUSlave support function codes 1 (Read Coils), 2 (Read Discrete Inputs), 3 (Read Holding Registers), 4 (Read Input Registers), 5 (Write Single Coil), 6 (Write Single Holding Register), 15 (Write Multiple Coils), and 16 (Write Multiple Holding Registers).

UiFlow2 Example
---------------

CoreS3 RTU Slave
^^^^^^^^^^^^^^^^

Open the |cores3_rtu_slave_example.m5f2| project in UiFlow2.

This example demonstrates how to use the ``ModbusRTUSlave`` class.

UiFlow2 Code Block:

    |example.png|

Example output:

    None

MicroPython Example
-------------------

CoreS3 RTU Slave
^^^^^^^^^^^^^^^^

This example demonstrates how to use the ``ModbusRTUSlave`` class.

MicroPython Code Block:

    .. literalinclude:: ../../../examples/software/modbus/cores3_rtu_slave_example.py
        :language: python
        :linenos:

Example output:

    None

API
---

ModbusRTUSlave
^^^^^^^^^^^^^^

.. class:: ModbusRTUSlave(uart, device_address: int = 1, context=None, ignore_unit_id: bool = False, verbose: bool = False)

    Create a ModbusRTUSlave object.

    :param UART uart: UART object or RS485 object.
    :param int device_address: Device address. The address is 0 to 247.
    :param dict context: Modbus server context.
    :param bool ignore_unit_id: Ignore unit ID(or Device address).
    :param bool verbose: Verbose mode.

    ``context`` is a dictionary that contains the Modbus server context. the format is as follows::

        {
            "discrete_inputs": [
                {
                    "register": 0,  # Start address of the discrete inputs.
                    "value": [False, True, False, True]  # Values of the discrete inputs. quantity is the length of the list.
                }
            ],
            "coils": [
                {
                    "register": 0,  # Start address of the coils.
                    "value": [False, True, False, True]  # Values of the coils. quantity is the length of the list. quantity is the length of the list.
                }
            ],
            "input_registers": [
                {
                    "register": 0,  # Start address of the input registers.
                    "value": [0x0000, 0x0001, 0x0002, 0x0003]  # Values of the input registers. quantity is the length of the list. quantity is the length of the list.
                }
            ],
            "holding_registers": [
                {
                    "register": 0,  # Start address of the holding registers.
                    "value": [0x0000, 0x0001, 0x0002, 0x0003]  # Values of the holding registers. quantity is the length of the list. quantity is the length of the list.
                }
            ],
        }

    UiFlow2 Code Block:

        |init.png|

    MicroPython Code Block:

        .. code-block:: python

            from modbus import ModbusRTUSlave
            # slave = ModbusRTUSlave(uart, device_address=1, context=context)


    .. py:method:: ModbusRTUSlave.start()

        Start the Modbus RTU slave.

        :returns: None

        UiFlow2 Code Block:

            |start.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.start()


    .. py:method:: ModbusRTUSlave.stop()

        Stop the Modbus RTU slave.

        :returns: None

        UiFlow2 Code Block:

            |stop.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.stop()


    .. py:method:: ModbusRTUSlave.add_coil(register: int, value: bool)

        Add a coil to the modbus register dictionary.

        :param int register: address of the coils. The address is 0x0000 to 0xFFFF.
        :param bool value: Value to add. The value is True or False.
        :returns: None

        UiFlow2 Code Block:

            |add_coil.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.add_coil(0, True)


    .. py:method:: ModbusRTUSlave.add_discrete_input(register: int, value: bool)

        Add a discrete input to the modbus register dictionary.

        :param int register: address of the discrete inputs. The address is 0x0000 to 0xFFFF.
        :param bool value: Value to add. The value is True or False.
        :returns: None

        UiFlow2 Code Block:

            |add_discrete_input.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.add_discrete_input(0, True)


    .. py:method:: ModbusRTUSlave.add_holding_register(register: int, value: int)

        Add a holding register to the modbus register dictionary.

        :param int register: address of the holding registers. The address is 0x0000 to 0xFFFF.
        :param int value: Value to add. The value is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |add_holding_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.add_holding_register(0, 100)


    .. py:method:: ModbusRTUSlave.add_input_register(register: int, value: int)

        Add an input register to the modbus register dictionary.

        :param int register: address of the input registers. The address is 0x0000 to 0xFFFF.
        :param int value: Value to add. The value is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |add_input_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.add_input_register(0, 100)


    .. py:method:: ModbusRTUSlave.remove_coil(register: int)

        Remove a coil from the modbus register dictionary.

        :param int register: address of the coils. The address is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |remove_coil.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.remove_coil(0)


    .. py:method:: ModbusRTUSlave.remove_discrete_input(register: int)

        Remove a discrete input from the modbus register dictionary.

        :param int register: address of the discrete inputs. The address is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |remove_discrete_input.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.remove_discrete_input(0)


    .. py:method:: ModbusRTUSlave.remove_holding_register(register: int)

        Remove a holding register from the modbus register dictionary.

        :param int register: address of the holding registers. The address is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |remove_holding_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.remove_holding_register(0)


    .. py:method:: ModbusRTUSlave.remove_input_register(register: int)

        Remove an input register from the modbus register dictionary.

        :param int register: address of the input registers. The address is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |remove_input_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.remove_input_register(0)


    .. py:method:: ModbusRTUSlave.get_coil(register: int)

        Get the coil value.

        :param int register: address of the coils. The address is 0x0000 to 0xFFFF.
        :returns: bool - The value of the coil.

        UiFlow2 Code Block:

            |get_coil.png|

        MicroPython Code Block:

            .. code-block:: python

                value = slave.get_coil(0)


    .. py:method:: ModbusRTUSlave.get_discrete_input(register: int)

        Get the discrete input value.

        :param int register: address of the discrete inputs. The address is 0x0000 to 0xFFFF.
        :returns: bool - The value of the discrete input.

        UiFlow2 Code Block:

            |get_discrete_input.png|

        MicroPython Code Block:

            .. code-block:: python

                value = slave.get_discrete_input(0)


    .. py:method:: ModbusRTUSlave.get_holding_register(register: int)

        Get the holding register value.

        :param int register: address of the holding registers. The address is 0x0000 to 0xFFFF.
        :returns: int - The value of the holding register.

        UiFlow2 Code Block:

            |get_holding_register.png|

        MicroPython Code Block:

            .. code-block:: python

                value = slave.get_holding_register(0)


    .. py:method:: ModbusRTUSlave.get_input_register(register: int)

        Get the input register value.

        :param int register: address of the input registers. The address is 0x0000 to 0xFFFF.
        :returns: int - The value of the input register.

        UiFlow2 Code Block:

            |get_input_register.png|

        MicroPython Code Block:

            .. code-block:: python

                value = slave.get_input_register(0)


    .. py:method:: ModbusRTUSlave.set_coil(register: int, value: bool)

        Set the coil value.

        :param int register: address of the coils. The address is 0x0000 to 0xFFFF.
        :param bool value: Value to set. The value is True or False.
        :returns: None

        UiFlow2 Code Block:

            |set_coil.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_coil(0, True)


    .. py:method:: ModbusRTUSlave.set_multi_coils(register: int, value: list)

        Set the multi coils value.

        :param int register: address of the coils. The address is 0x0000 to 0xFFFF.
        :param list value: Values to set. The value is a list of True or False.
        :returns: None

        UiFlow2 Code Block:

            |set_multi_coils.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_multi_coils(0, [True, False])


    .. py:method:: ModbusRTUSlave.set_discrete_input(register: int, value: bool)

        Set the discrete input value.

        :param int register: address of the discrete inputs. The address is 0x0000 to 0xFFFF.
        :param bool value: Value to set. The value is True or False.
        :returns: None

        UiFlow2 Code Block:

            |set_discrete_input.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_discrete_input(0, True)


    .. py:method:: ModbusRTUSlave.set_multi_discrete_input(register: int, value: list)

        Set the multi discrete inputs value.

        :param int register: address of the discrete inputs. The address is 0x0000 to 0xFFFF.
        :param list value: Values to set. The value is a list of True or False.
        :returns: None

        UiFlow2 Code Block:

            |set_multi_discrete_input.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_multi_discrete_input(0, [True, False])


    .. py:method:: ModbusRTUSlave.set_holding_register(register: int, value: int)

        Set the holding register value.

        :param int register: address of the holding registers. The address is 0x0000 to 0xFFFF.
        :param int value: Value to set. The value is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |set_holding_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_holding_register(0, 100)


    .. py:method:: ModbusRTUSlave.set_multi_holding_register(register: int, value: list)

        Set the multi holding registers value.

        :param int register: address of the holding registers. The address is 0x0000 to 0xFFFF.
        :param list value: Values to set. The value is a list of 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |set_multi_holding_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_multi_holding_register(0, [100, 200])


    .. py:method:: ModbusRTUSlave.set_input_register(register: int, value: int)

        Set the input register value.

        :param int register: address of the input registers. The address is 0x0000 to 0xFFFF.
        :param int value: Value to set. The value is 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |set_input_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_input_register(0, 100)


    .. py:method:: ModbusRTUSlave.set_multi_input_register(register: int, value: list)

        Set the multi input registers value.

        :param int register: address of the input registers. The address is 0x0000 to 0xFFFF.
        :param list value: Values to set. The value is a list of 0x0000 to 0xFFFF.
        :returns: None

        UiFlow2 Code Block:

            |set_multi_input_register.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.set_multi_input_register(0, [100, 200])


    .. py:method:: ModbusRTUSlave.tick()

        Modbus RTU slave tick function. This function should be called in the main loop.

        :returns: None

        UiFlow2 Code Block:

            |tick.png|

        MicroPython Code Block:

            .. code-block:: python

                slave.tick()


    .. py:method:: ModbusRTUSlave.set_callback(func_code: int, handler)

        Set the callback function for the function code.

        :param int func_code: Function code. The function code is 1 to 6, 15, 16. the symbol is defined in the modbus.ModbusRTUSlave (\*_EVENT etc.).
        :param handler: Callback function.
        :returns: None

        UiFlow2 Code Block:

            |read_coils_callback.png|

            |read_discrete_inputs_callback.png|

            |read_holding_registers_callback.png|

            |read_input_registers_callback.png|

            |write_multiple_coils_callback.png|

            |write_multiple_registers_callback.png|

            |write_single_coil_callback.png|

            |write_single_register_callback.png|

        MicroPython Code Block:

            .. code-block:: python

                def callback(arg):
                    pass
                slave.set_callback(1, callback)


    .. py:data:: ModbusRTUSlave.READ_COILS_EVENT

        Function code 1 (Read Coils).


    .. py:data:: ModbusRTUSlave.READ_DISCRETE_INPUTS_EVENT

        Function code 2 (Read Discrete Inputs).


    .. py:data:: ModbusRTUSlave.READ_HOLDING_REGISTERS_EVENT

        Function code 3 (Read Holding Registers).


    .. py:data:: ModbusRTUSlave.READ_INPUT_REGISTERS_EVENT

        Function code 4 (Read Input Registers).


    .. py:data:: ModbusRTUSlave.WRITE_SINGLE_COIL_EVENT

        Function code 5 (Write Single Coil).


    .. py:data:: ModbusRTUSlave.WRITE_SINGLE_HOLDING_REGISTER_EVENT

        Function code 6 (Write Single Holding Register).


    .. py:data:: ModbusRTUSlave.WRITE_MULTIPLE_COILS_EVENT

        Function code 15 (Write Multiple Coils).


    .. py:data:: ModbusRTUSlave.WRITE_MULTIPLE_HOLDING_REGISTERS_EVENT

        Function code 16 (Write Multiple Holding Registers).