modbus_client.send: fire a raw PDU (function code + data; the hub adds address and CRC). More...

#include <modbus_client.h>

Inheritance diagram for esphome::modbus_client::ModbusClientSendAction< Ts >:

Public Member Functions
	TEMPLATABLE_VALUE (modbus::helpers::PduBuffer, pdu) Trigger< std

void	play (const Ts &...x) override

void	on_response (std::span< const uint8_t > request_pdu, std::span< const uint8_t > response_pdu) override

Public Member Functions inherited from esphome::modbus_client::ClientActionBase< Ts... >
	TEMPLATABLE_VALUE (uint8_t, target_address) Trigger< std

Trigger< std::span< const uint8_t >, modbus::ExceptionCode > *	get_error_trigger ()

Trigger< std::span< const uint8_t > > *	get_no_response_trigger ()

Trigger< std::span< const uint8_t > > *	get_not_sent_trigger ()

void	set_retry (retry_func_t f)

void	on_sent (std::span< const uint8_t > request_pdu) override
	The frame was written to the wire: fires once per transmission, before any reply, and never for a send that ended in on_not_sent.

void	on_not_sent (std::span< const uint8_t > request_pdu) override
	Never reached the wire, from either of two sources.

void	on_error (std::span< const uint8_t > request_pdu, modbus::ExceptionCode exception_code) override
	A Modbus exception reply.

bool	on_no_response (std::span< const uint8_t > request_pdu) override
	No reply within send_wait_time.

void	play_complex (const Ts &...x) override
	Stamp the templated device address before every play(): subclasses cannot forget it, and the hub routes each reply by device pointer, so a changed address never mis-routes earlier replies.

Public Member Functions inherited from esphome::Action< Ts... >
virtual void	stop_complex ()

virtual bool	is_running ()
	Check if this or any of the following actions are currently running.

int	num_running_total ()
	The total number of actions that are currently running in this plus any of the following actions in the chain.

Public Member Functions inherited from esphome::modbus::ModbusClientDevice
	ModbusClientDevice ()=default

	ModbusClientDevice (ModbusClientHub *parent, uint8_t address)

virtual	~ModbusClientDevice ()

	ModbusClientDevice (const ModbusClientDevice &)=delete

ModbusClientDevice &	operator= (const ModbusClientDevice &)=delete

	ModbusClientDevice (ModbusClientDevice &&)=delete

ModbusClientDevice &	operator= (ModbusClientDevice &&)=delete

void	set_parent (ModbusClientHub *parent)

void	set_address (uint8_t address)

	ESPDEPRECATED ("Override on_not_sent() instead. Removed in 2027.2.0", "2026.8.0") virtual void on_modbus_not_sent()

	ESPDEPRECATED ("Override on_no_response() instead. Removed in 2027.2.0", "2026.8.0") virtual bool on_modbus_no_response()

virtual void	on_read_registers (EntityType entity_type, uint16_t start_address, std::span< const uint16_t > registers, ResponseStatus status)
	High-level typed response callbacks, fired by the default on_response()/on_error() with arguments parsed from the request and response PDUs.

virtual void	on_read_holding_registers (uint16_t start_address, std::span< const uint16_t > registers, ResponseStatus status)

virtual void	on_read_input_registers (uint16_t start_address, std::span< const uint16_t > registers, ResponseStatus status)

virtual void	on_read_bits (EntityType entity_type, uint16_t start_address, PackedBits bits, ResponseStatus status)
	Coil/discrete-input reads are delivered as a PackedBits view (bit 0 = the bit at start_address, bits.size() = the count requested).

virtual void	on_read_coils (uint16_t start_address, PackedBits bits, ResponseStatus status)

virtual void	on_read_discrete_inputs (uint16_t start_address, PackedBits bits, ResponseStatus status)

virtual void	on_write_single_register (uint16_t address, uint16_t value, ResponseStatus status)
	Write acknowledgements.

virtual void	on_write_single_coil (uint16_t address, bool value, ResponseStatus status)

virtual void	on_write_multiple_registers (uint16_t start_address, std::span< const uint16_t > registers, ResponseStatus status)

virtual void	on_write_multiple_coils (uint16_t start_address, PackedBits bits, ResponseStatus status)

virtual void	on_custom_response (std::span< const uint8_t > request_pdu, std::span< const uint8_t > response_pdu, ResponseStatus status)
	Catch-all for custom function codes and anything that is not a standard-conformant transaction (see dispatch_response_()); on failure the response is empty and the exception code is in status.

	ESPDEPRECATED ("Use the typed read_/write_ helpers or queue_pdu() instead. Removed in 2027.2.0", "2026.8.0") void send(uint8_t function

Protected Attributes
Trigger< std::span< const uint8_t >, std::span< const uint8_t > >	response_trigger_

Protected Attributes inherited from esphome::modbus_client::ClientActionBase< Ts... >
Trigger< std::span< const uint8_t > >	sent_trigger_

Trigger< std::span< const uint8_t >, modbus::ExceptionCode >	error_trigger_

Trigger< std::span< const uint8_t > >	no_response_trigger_

Trigger< std::span< const uint8_t > >	not_sent_trigger_

retry_func_t	retry_func_

Protected Attributes inherited from esphome::Action< Ts... >
friend	ActionList< Ts... >

Action< Ts... > *	next_

int	num_running_
	The number of instances of this sequence in the list of actions that is currently being executed.

Additional Inherited Members
Public Types inherited from esphome::modbus_client::ClientActionBase< Ts... >
using	retry_func_t
	The retry decision for on_no_response: given the request PDU, return true to have the hub re-queue the frame.

Data Fields inherited from esphome::modbus::ModbusClientDevice
uint16_t	start_address

uint16_t uint16_t	number_of_entities

uint16_t uint16_t uint8_t	payload_len = 0

uint16_t uint16_t uint8_t const uint8_t *	payload

ModbusClientHub *	parent_ {nullptr}

uint8_t	address_ {0}

bool	custom_response_warned_ {false}

Protected Member Functions inherited from esphome::modbus_client::ClientActionBase< Ts... >
void	send_or_resolve_ (std::span< const uint8_t > pdu)
	The hub refuses some sends at the door with no callback (a duplicate write already pending, a full queue, or an empty PDU - which is how the create_*_pdu() builders reject out-of-spec input).

Protected Member Functions inherited from esphome::Action< Ts... >
void	play_next_ (const Ts &...x)

void	play_next_tuple_ (const std::tuple< Ts... > &tuple, std::index_sequence< S... >)

void	play_next_tuple_ (const std::tuple< Ts... > &tuple)

virtual void	stop ()

void	stop_next_ ()

bool	is_running_next_ ()

Detailed Description

template<typename... Ts>
class esphome::modbus_client::ModbusClientSendAction< Ts >

modbus_client.send: fire a raw PDU (function code + data; the hub adds address and CRC).

The reply is delivered raw - on_response(request, response) - deliberately bypassing the typed dispatch, so non-standard/custom transactions pass through untouched. The PDU is a stack-allocated modbus::helpers::PduBuffer, so a pdu lambda can build one with the modbus::helpers::create_*_pdu() builders and return it directly (smaller builder results convert). A PduBuffer drops bytes past modbus::MAX_PDU_SIZE without reporting it (the hub's oversize check cannot fire - that limit is the capacity), so an over-long lambda-built PDU is silently truncated.

Definition at line 90 of file modbus_client.h.

Member Function Documentation

◆ on_response()

template<typename... Ts>

void esphome::modbus_client::ModbusClientSendAction< Ts >::on_response	(	std::span< const uint8_t >	request_pdu,
		std::span< const uint8_t >	response_pdu )

inlineoverridevirtual

Reimplemented from esphome::modbus::ModbusClientDevice.

Definition at line 100 of file modbus_client.h.

◆ play()

template<typename... Ts>

void esphome::modbus_client::ModbusClientSendAction< Ts >::play ( const Ts &... x )

inlineoverridevirtual

Implements esphome::Action< Ts... >.

Definition at line 98 of file modbus_client.h.

◆ TEMPLATABLE_VALUE()

template<typename... Ts>

esphome::modbus_client::ModbusClientSendAction< Ts >::TEMPLATABLE_VALUE	(	modbus::helpers::PduBuffer	,
		pdu	)

inline

Definition at line 92 of file modbus_client.h.

Field Documentation

◆ response_trigger_

template<typename... Ts>

Trigger<std::span<const uint8_t>, std::span<const uint8_t> > esphome::modbus_client::ModbusClientSendAction< Ts >::response_trigger_

protected

Definition at line 105 of file modbus_client.h.

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

esphome/components/modbus_client/modbus_client.h

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ on_response()

◆ play()

◆ TEMPLATABLE_VALUE()

Field Documentation

◆ response_trigger_