Modbus controller class. More...

#include <modbus_controller.h>

Inheritance diagram for esphome::modbus_controller::ModbusController:

Public Member Functions
void	dump_config () override

void	loop () override

void	setup () override

void	update () override

void	queue_command (const ModbusCommandItem &command)
	queues a modbus command in the send queue

void	add_sensor_item (SensorItem *item)
	Registers a sensor with the controller. Called by esphomes code generator.

void	on_modbus_data (const std::vector< uint8_t > &data) override
	called when a modbus response was parsed without errors

void	on_modbus_error (uint8_t function_code, uint8_t exception_code) override
	called when a modbus error response was received

void	on_register_data (ModbusRegisterType register_type, uint16_t start_address, const std::vector< uint8_t > &data)
	default delegate called by process_modbus_data when a response has retrieved from the incoming queue

void	on_write_register_response (ModbusRegisterType register_type, uint16_t start_address, const std::vector< uint8_t > &data)
	default delegate called by process_modbus_data when a response for a write response has retrieved from the incoming queue

void	set_allow_duplicate_commands (bool allow_duplicate_commands)
	Allow a duplicate command to be sent.

bool	get_allow_duplicate_commands ()
	get if a duplicate command can be sent

void	set_command_throttle (uint16_t command_throttle)
	called by esphome generated code to set the command_throttle period

void	set_offline_skip_updates (uint16_t offline_skip_updates)
	called by esphome generated code to set the offline_skip_updates

size_t	get_command_queue_length ()
	get the number of queued modbus commands (should be mostly empty)

bool	get_module_offline ()
	get if the module is offline, didn't respond the last command

template<typename F >
void	add_on_command_sent_callback (F &&callback)
	Set callback for commands.

template<typename F >
void	add_on_online_callback (F &&callback)
	Set callback for online changes.

template<typename F >
void	add_on_offline_callback (F &&callback)
	Set callback for offline changes.

void	set_max_cmd_retries (uint8_t max_cmd_retries)
	called by esphome generated code to set the max_cmd_retries.

uint8_t	get_max_cmd_retries ()
	get how many times a command will be (re)sent if no response is received

Public Member Functions inherited from esphome::PollingComponent
	PollingComponent ()

	PollingComponent (uint32_t update_interval)
	Initialize this polling component with the given update interval in ms.

void	set_update_interval (uint32_t update_interval)
	Manually set the update interval in ms for this polling object.

void	call_setup () override

virtual uint32_t	get_update_interval () const
	Get the update interval in ms of this sensor.

void	start_poller ()

void	stop_poller ()

Public Member Functions inherited from esphome::Component
virtual float	get_setup_priority () const
	priority of setup().

float	get_actual_setup_priority () const

void	set_setup_priority (float priority)

void	call ()

virtual void	on_shutdown ()

virtual void	on_safe_shutdown ()

virtual bool	teardown ()
	Called during teardown to allow component to gracefully finish operations.

virtual void	on_powerdown ()
	Called after teardown is complete to power down hardware.

uint8_t	get_component_state () const

void	reset_to_construction_state ()
	Reset this component back to the construction state to allow setup to run again.

bool	is_in_loop_state () const
	Check if this component has completed setup and is in the loop state.

bool	is_idle () const
	Check if this component is idle.

void	mark_failed ()
	Mark this component as failed.

	ESPDEPRECATED ("Use mark_failed(LOG_STR(\"static string literal\")) instead. Do NOT use .c_str() from temporary " "strings. Will stop working in 2026.6.0", "2025.12.0") void mark_failed(const char *message)

void	mark_failed (const LogString *message)

void	disable_loop ()
	Disable this component's loop.

void	enable_loop ()
	Enable this component's loop.

void	enable_loop_soon_any_context ()
	Thread and ISR-safe version of enable_loop() that can be called from any context.

bool	is_failed () const

bool	is_ready () const

virtual bool	can_proceed ()

bool	status_has_warning () const

bool	status_has_error () const

void	status_set_warning ()

void	status_set_warning (const char *message)

void	status_set_warning (const LogString *message)

void	status_set_error ()

	ESPDEPRECATED ("Use status_set_error(LOG_STR(\"static string literal\")) instead. Do NOT use .c_str() from temporary " "strings. Will stop working in 2026.6.0", "2025.12.0") void status_set_error(const char *message)

void	status_set_error (const LogString *message)

void	status_clear_warning ()

void	status_clear_error ()

void	status_momentary_warning (const char *name, uint32_t length=5000)
	Set warning status flag and automatically clear it after a timeout.

void	status_momentary_error (const char *name, uint32_t length=5000)
	Set error status flag and automatically clear it after a timeout.

bool	has_overridden_loop () const

const LogString *	get_component_log_str () const ESPHOME_ALWAYS_INLINE
	Get the integration where this component was declared as a LogString for logging.

bool	should_warn_of_blocking (uint32_t blocking_time)

Public Member Functions inherited from esphome::modbus::ModbusDevice
void	set_parent (Modbus *parent)

void	set_address (uint8_t address)

virtual void	on_modbus_read_registers (uint8_t function_code, uint16_t start_address, uint16_t number_of_registers)

virtual void	on_modbus_write_registers (uint8_t function_code, const std::vector< uint8_t > &data)

void	send (uint8_t function, uint16_t start_address, uint16_t number_of_entities, uint8_t payload_len=0, const uint8_t *payload=nullptr)

void	send_raw (const std::vector< uint8_t > &payload)

void	send_error (uint8_t function_code, ModbusExceptionCode exception_code)

	ESPDEPRECATED ("Use ready_for_immediate_send() instead. Removed in 2026.9.0", "2026.3.0") bool waiting_for_response()

bool	ready_for_immediate_send ()

Protected Member Functions
size_t	create_register_ranges_ ()
	parse sensormap_ and create range of sequential addresses

SensorSet	find_sensors_ (ModbusRegisterType register_type, uint16_t start_address) const

void	update_range_ (RegisterRange &r)
	submit the read command for the address range to the send queue

void	process_modbus_data_ (const ModbusCommandItem *response)
	parse incoming modbus data

bool	send_next_command_ ()
	send the next modbus command from the send queue

void	dump_sensors_ ()
	dump the parsed sensormap for diagnostics

Protected Member Functions inherited from esphome::Component
friend	void::setup ()

friend	void::original_setup ()

void	set_component_source_ (uint8_t index)
	Set where this component was loaded from for some debug messages.

void	call_dump_config_ ()

void	enable_loop_slow_path_ ()

void	set_component_state_ (uint8_t state)
	Helper to set component state (clears state bits and sets new state)

bool	set_status_flag_ (uint8_t flag)
	Helper to set a status LED flag on both this component and the app.

void	set_interval (uint32_t id, uint32_t interval, std::function< void()> &&f)
	Set an interval function with a numeric ID (zero heap allocation).

void	set_interval (InternalSchedulerID id, uint32_t interval, std::function< void()> &&f)

void	set_interval (uint32_t interval, std::function< void()> &&f)

bool	cancel_interval (uint32_t id)

bool	cancel_interval (InternalSchedulerID id)

ESPDEPRECATED("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const std	ESPDEPRECATED ("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const char *name

	ESPDEPRECATED ("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(uint32_t id

	ESPDEPRECATED ("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(uint32_t initial_wait_time

ESPDEPRECATED("cancel_retry is deprecated and will be removed in 2026.8.0.", "2026.2.0") bool cancel_retry(const std	ESPDEPRECATED ("cancel_retry is deprecated and will be removed in 2026.8.0.", "2026.2.0") bool cancel_retry(const char *name)

	ESPDEPRECATED ("cancel_retry is deprecated and will be removed in 2026.8.0.", "2026.2.0") bool cancel_retry(uint32_t id)

void	set_timeout (uint32_t id, uint32_t timeout, std::function< void()> &&f)
	Set a timeout function with a numeric ID (zero heap allocation).

void	set_timeout (InternalSchedulerID id, uint32_t timeout, std::function< void()> &&f)

void	set_timeout (uint32_t timeout, std::function< void()> &&f)

bool	cancel_timeout (uint32_t id)

bool	cancel_timeout (InternalSchedulerID id)

void	defer (std::function< void()> &&f)
	Defer a callback to the next loop() call.

void	defer (uint32_t id, std::function< void()> &&f)
	Defer a callback with a numeric ID (zero heap allocation)

bool	cancel_defer (uint32_t id)

void	status_clear_warning_slow_path_ ()

void	status_clear_error_slow_path_ ()

Protected Attributes
SensorSet	sensorset_
	Collection of all sensors for this component.

std::vector< RegisterRange >	register_ranges_ {}
	Continuous range of modbus registers.

std::list< std::unique_ptr< ModbusCommandItem > >	command_queue_
	Hold the pending requests to be sent.

std::queue< std::unique_ptr< ModbusCommandItem > >	incoming_queue_
	modbus response data waiting to get processed

bool	allow_duplicate_commands_ {false}
	if duplicate commands can be sent

uint32_t	last_command_timestamp_ {0}
	when was the last send operation

uint16_t	command_throttle_ {0}
	min time in ms between sending modbus commands

bool	module_offline_ {false}
	if module didn't respond the last command

uint16_t	offline_skip_updates_ {0}
	how many updates to skip if module is offline

uint8_t	max_cmd_retries_ {4}
	How many times we will retry a command if we get no response.

CallbackManager< void(int, int)>	command_sent_callback_ {}
	Command sent callback.

CallbackManager< void(int, int)>	online_callback_ {}
	Server online callback.

CallbackManager< void(int, int)>	offline_callback_ {}
	Server offline callback.

Protected Attributes inherited from esphome::PollingComponent
uint32_t	update_interval_

Protected Attributes inherited from esphome::Component
ESPDEPRECATED("Use const char* or uint32_t overload instead. Removed in 2026.7.0", "2026.1.0") void set_interval(const std voi	set_interval )(const char *name, uint32_t interval, std::function< void()> &&f)
	Set an interval function with a unique name.

ESPDEPRECATED("Use const char* or uint32_t overload instead. Removed in 2026.7.0", "2026.1.0") bool cancel_interval(const std boo	cancel_interval )(const char *name)
	Cancel an interval function.

ESPDEPRECATED("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const std uint32_t	initial_wait_time

ESPDEPRECATED("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const std uint32_t uint8_t	max_attempts

ESPDEPRECATED("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const std uint32_t uint8_t std::function< RetryResult(uint8_t)> &&	f

ESPDEPRECATED("set_retry is deprecated and will be removed in 2026.8.0. Use set_timeout or set_interval instead.", "2026.2.0") void set_retry(const std uint32_t uint8_t std::function< RetryResult(uint8_t)> float	backoff_increase_factor = 1.0f)

uint32_t	initial_wait_time

uint32_t uint8_t	max_attempts

uint32_t uint8_t std::function< RetryResult(uint8_t)> &&	f

uint32_t uint8_t std::function< RetryResult(uint8_t)> float	backoff_increase_factor = 1.0f)

uint8_t	max_attempts

uint8_t std::function< RetryResult(uint8_t)> &&	f

uint8_t std::function< RetryResult(uint8_t)> float	backoff_increase_factor = 1.0f)

ESPDEPRECATED("Use const char* or uint32_t overload instead. Removed in 2026.7.0", "2026.1.0") void set_timeout(const std voi	set_timeout )(const char *name, uint32_t timeout, std::function< void()> &&f)
	Set a timeout function with a unique name.

ESPDEPRECATED("Use const char* or uint32_t overload instead. Removed in 2026.7.0", "2026.1.0") bool cancel_timeout(const std boo	cancel_timeout )(const char *name)
	Cancel a timeout function.

ESPDEPRECATED("Use const char* overload instead. Removed in 2026.7.0", "2026.1.0") void defer(const std voi	defer )(const char *name, std::function< void()> &&f)
	Defer a callback to the next loop() call.

ESPDEPRECATED("Use const char* overload instead. Removed in 2026.7.0", "2026.1.0") bool cancel_defer(const std boo	cancel_defer )(const char *name)
	Cancel a defer callback using the specified name, name must not be empty.

uint8_t	component_source_index_ {0}
	Index into component source PROGMEM lookup table (0 = not set)

uint8_t	warn_if_blocking_over_ {WARN_IF_BLOCKING_OVER_CS}
	Warn threshold in centiseconds (max 2550ms)

uint8_t	component_state_ {0x00}
	State of this component - each bit has a purpose: Bits 0-2: Component state (0x00=CONSTRUCTION, 0x01=SETUP, 0x02=LOOP, 0x03=FAILED, 0x04=LOOP_DONE) Bit 3: STATUS_LED_WARNING Bit 4: STATUS_LED_ERROR Bit 5: Has overridden loop() (set at registration time) Bits 6-7: Unused - reserved for future expansion.

volatile bool	pending_enable_loop_ {false}
	ISR-safe flag for enable_loop_soon_any_context.

ComponentRuntimeStats	runtime_stats_

Protected Attributes inherited from esphome::modbus::ModbusDevice
friend	Modbus

Modbus *	parent_

uint8_t	address_

Detailed Description

Modbus controller class.

Each instance handles the modbus commuinication for all sensors with the same modbus address

all sensor items (sensors, switches, binarysensor ...) are parsed in modbus address ranges. when esphome calls ModbusController::Update the commands for each range are created and sent Responses for the commands are dispatched to the modbus sensor items.

Definition at line 282 of file modbus_controller.h.

Member Function Documentation

◆ add_on_command_sent_callback()

template<typename F >

void esphome::modbus_controller::ModbusController::add_on_command_sent_callback ( F && callback )

inline

Set callback for commands.

Definition at line 318 of file modbus_controller.h.

◆ add_on_offline_callback()

template<typename F >

void esphome::modbus_controller::ModbusController::add_on_offline_callback ( F && callback )

inline

Set callback for offline changes.

Definition at line 326 of file modbus_controller.h.

◆ add_on_online_callback()

template<typename F >

void esphome::modbus_controller::ModbusController::add_on_online_callback ( F && callback )

inline

Set callback for online changes.

Definition at line 322 of file modbus_controller.h.

◆ add_sensor_item()

void esphome::modbus_controller::ModbusController::add_sensor_item ( SensorItem * item )

inline

Registers a sensor with the controller. Called by esphomes code generator.

Definition at line 292 of file modbus_controller.h.

◆ create_register_ranges_()

size_t esphome::modbus_controller::ModbusController::create_register_ranges_ ( )

protected

parse sensormap_ and create range of sequential addresses

Definition at line 202 of file modbus_controller.cpp.

◆ dump_config()

void esphome::modbus_controller::ModbusController::dump_config ( )

overridevirtual

Reimplemented from esphome::Component.

Definition at line 308 of file modbus_controller.cpp.

◆ dump_sensors_()

void esphome::modbus_controller::ModbusController::dump_sensors_ ( )

protected

dump the parsed sensormap for diagnostics

Definition at line 351 of file modbus_controller.cpp.

◆ find_sensors_()

SensorSet esphome::modbus_controller::ModbusController::find_sensors_	(	ModbusRegisterType	register_type,
		uint16_t	start_address ) const

protected

Definition at line 114 of file modbus_controller.cpp.

◆ get_allow_duplicate_commands()

bool esphome::modbus_controller::ModbusController::get_allow_duplicate_commands ( )

inline

get if a duplicate command can be sent

Definition at line 308 of file modbus_controller.h.

◆ get_command_queue_length()

size_t esphome::modbus_controller::ModbusController::get_command_queue_length ( )

inline

get the number of queued modbus commands (should be mostly empty)

Definition at line 314 of file modbus_controller.h.

◆ get_max_cmd_retries()

uint8_t esphome::modbus_controller::ModbusController::get_max_cmd_retries ( )

inline

get how many times a command will be (re)sent if no response is received

Definition at line 332 of file modbus_controller.h.

◆ get_module_offline()

bool esphome::modbus_controller::ModbusController::get_module_offline ( )

inline

get if the module is offline, didn't respond the last command

Definition at line 316 of file modbus_controller.h.

◆ loop()

void esphome::modbus_controller::ModbusController::loop ( )

overridevirtual

Reimplemented from esphome::Component.

Definition at line 331 of file modbus_controller.cpp.

◆ on_modbus_data()

void esphome::modbus_controller::ModbusController::on_modbus_data ( const std::vector< uint8_t > & data )

overridevirtual

called when a modbus response was parsed without errors

Implements esphome::modbus::ModbusDevice.

Definition at line 60 of file modbus_controller.cpp.

◆ on_modbus_error()

void esphome::modbus_controller::ModbusController::on_modbus_error	(	uint8_t	function_code,
		uint8_t	exception_code )

overridevirtual

called when a modbus error response was received

Reimplemented from esphome::modbus::ModbusDevice.

Definition at line 96 of file modbus_controller.cpp.

◆ on_register_data()

void esphome::modbus_controller::ModbusController::on_register_data	(	ModbusRegisterType	register_type,
		uint16_t	start_address,
		const std::vector< uint8_t > &	data )

default delegate called by process_modbus_data when a response has retrieved from the incoming queue

Definition at line 128 of file modbus_controller.cpp.

◆ on_write_register_response()

void esphome::modbus_controller::ModbusController::on_write_register_response	(	ModbusRegisterType	register_type,
		uint16_t	start_address,
		const std::vector< uint8_t > &	data )

default delegate called by process_modbus_data when a response for a write response has retrieved from the incoming queue

Definition at line 345 of file modbus_controller.cpp.

◆ process_modbus_data_()

void esphome::modbus_controller::ModbusController::process_modbus_data_ ( const ModbusCommandItem * response )

protected

parse incoming modbus data

Definition at line 90 of file modbus_controller.cpp.

◆ queue_command()

void esphome::modbus_controller::ModbusController::queue_command ( const ModbusCommandItem & command )

queues a modbus command in the send queue

Definition at line 139 of file modbus_controller.cpp.

◆ send_next_command_()

bool esphome::modbus_controller::ModbusController::send_next_command_ ( )

protected

send the next modbus command from the send queue

Definition at line 17 of file modbus_controller.cpp.

◆ set_allow_duplicate_commands()

void esphome::modbus_controller::ModbusController::set_allow_duplicate_commands ( bool allow_duplicate_commands )

inline

Allow a duplicate command to be sent.

Definition at line 304 of file modbus_controller.h.

◆ set_command_throttle()

void esphome::modbus_controller::ModbusController::set_command_throttle ( uint16_t command_throttle )

inline

called by esphome generated code to set the command_throttle period

Definition at line 310 of file modbus_controller.h.

◆ set_max_cmd_retries()

void esphome::modbus_controller::ModbusController::set_max_cmd_retries ( uint8_t max_cmd_retries )

inline

called by esphome generated code to set the max_cmd_retries.

Definition at line 330 of file modbus_controller.h.

◆ set_offline_skip_updates()

void esphome::modbus_controller::ModbusController::set_offline_skip_updates ( uint16_t offline_skip_updates )

inline

called by esphome generated code to set the offline_skip_updates

Definition at line 312 of file modbus_controller.h.

◆ setup()

void esphome::modbus_controller::ModbusController::setup ( )

overridevirtual

Reimplemented from esphome::Component.

Definition at line 9 of file modbus_controller.cpp.

◆ update()

void esphome::modbus_controller::ModbusController::update ( )

overridevirtual

Implements esphome::PollingComponent.

Definition at line 188 of file modbus_controller.cpp.

◆ update_range_()

void esphome::modbus_controller::ModbusController::update_range_ ( RegisterRange & r )

protected

submit the read command for the address range to the send queue

Definition at line 157 of file modbus_controller.cpp.

Field Documentation

◆ allow_duplicate_commands_

bool esphome::modbus_controller::ModbusController::allow_duplicate_commands_ {false}

protected

if duplicate commands can be sent

Definition at line 356 of file modbus_controller.h.

◆ command_queue_

std::list<std::unique_ptr<ModbusCommandItem> > esphome::modbus_controller::ModbusController::command_queue_

protected

Hold the pending requests to be sent.

Definition at line 352 of file modbus_controller.h.

◆ command_sent_callback_

CallbackManager<void(int, int)> esphome::modbus_controller::ModbusController::command_sent_callback_ {}

protected

Command sent callback.

Definition at line 368 of file modbus_controller.h.

◆ command_throttle_

uint16_t esphome::modbus_controller::ModbusController::command_throttle_ {0}

protected

min time in ms between sending modbus commands

Definition at line 360 of file modbus_controller.h.

◆ incoming_queue_

std::queue<std::unique_ptr<ModbusCommandItem> > esphome::modbus_controller::ModbusController::incoming_queue_

protected

modbus response data waiting to get processed

Definition at line 354 of file modbus_controller.h.

◆ last_command_timestamp_

uint32_t esphome::modbus_controller::ModbusController::last_command_timestamp_ {0}

protected

when was the last send operation

Definition at line 358 of file modbus_controller.h.

◆ max_cmd_retries_

uint8_t esphome::modbus_controller::ModbusController::max_cmd_retries_ {4}

protected

How many times we will retry a command if we get no response.

Definition at line 366 of file modbus_controller.h.

◆ module_offline_

bool esphome::modbus_controller::ModbusController::module_offline_ {false}

protected

if module didn't respond the last command

Definition at line 362 of file modbus_controller.h.

◆ offline_callback_

CallbackManager<void(int, int)> esphome::modbus_controller::ModbusController::offline_callback_ {}

protected

Server offline callback.

Definition at line 372 of file modbus_controller.h.

◆ offline_skip_updates_

uint16_t esphome::modbus_controller::ModbusController::offline_skip_updates_ {0}

protected

how many updates to skip if module is offline

Definition at line 364 of file modbus_controller.h.

◆ online_callback_

CallbackManager<void(int, int)> esphome::modbus_controller::ModbusController::online_callback_ {}

protected

Server online callback.

Definition at line 370 of file modbus_controller.h.

◆ register_ranges_

std::vector<RegisterRange> esphome::modbus_controller::ModbusController::register_ranges_ {}

protected

Continuous range of modbus registers.

Definition at line 350 of file modbus_controller.h.

◆ sensorset_

SensorSet esphome::modbus_controller::ModbusController::sensorset_

protected

Collection of all sensors for this component.

Definition at line 348 of file modbus_controller.h.

The documentation for this class was generated from the following files:

esphome/components/modbus_controller/modbus_controller.h
esphome/components/modbus_controller/modbus_controller.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ add_on_command_sent_callback()

◆ add_on_offline_callback()

◆ add_on_online_callback()

◆ add_sensor_item()

◆ create_register_ranges_()

◆ dump_config()

◆ dump_sensors_()

◆ find_sensors_()

◆ get_allow_duplicate_commands()

◆ get_command_queue_length()

◆ get_max_cmd_retries()

◆ get_module_offline()

◆ loop()

◆ on_modbus_data()

◆ on_modbus_error()

◆ on_register_data()

◆ on_write_register_response()

◆ process_modbus_data_()

◆ queue_command()

◆ send_next_command_()

◆ set_allow_duplicate_commands()

◆ set_command_throttle()

◆ set_max_cmd_retries()

◆ set_offline_skip_updates()

◆ setup()

◆ update()

◆ update_range_()

Field Documentation

◆ allow_duplicate_commands_

◆ command_queue_

◆ command_sent_callback_

◆ command_throttle_

◆ incoming_queue_

◆ last_command_timestamp_

◆ max_cmd_retries_

◆ module_offline_

◆ offline_callback_

◆ offline_skip_updates_

◆ online_callback_

◆ register_ranges_

◆ sensorset_