Shared base for the modbus_client actions. More...

#include <modbus_client.h>

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

Public Types
using	retry_func_t = bool (*)(std::span<const uint8_t>)
	The retry decision for on_no_response: given the request PDU, return true to have the hub re-queue the frame.

Public Member Functions
	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)

virtual void	on_response (std::span< const uint8_t > request_pdu, std::span< const uint8_t > response_pdu)
	Low-level response hook: called with the request PDU this device sent and the response PDU received The spans are only valid for the duration of the call - copy the bytes if they must outlive it.

	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 Member Functions
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... >
virtual void	play (const Ts &...x)=0

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_ ()

Protected Attributes
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_ {nullptr}

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
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}

Detailed Description

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

Shared base for the modbus_client actions.

Each ACTION INSTANCE is its own modbus::ModbusClientDevice: the hub routes every reply (or its lack) straight back to the action that sent it, so there is no central client object and no request matching. The device address is templatable; it is stamped on the device at play() time; the hub routes each reply by device pointer, so a changed address never mis-routes an earlier reply. (The address is not passed to the reply triggers - under overlapping sends it could misreport, and the handler can recompute the expression it configured.)

Definition at line 18 of file modbus_client.h.

Member Typedef Documentation

◆ retry_func_t

template<typename... Ts>

using esphome::modbus_client::ClientActionBase< Ts >::retry_func_t = bool (*)(std::span<const uint8_t>)

The retry decision for on_no_response: given the request PDU, return true to have the hub re-queue the frame.

Set from the lambda form or a then: automation's nested retry lambda; may coexist with the no_response trigger (actions run, then this decides the retry).

Definition at line 30 of file modbus_client.h.

Member Function Documentation

◆ get_error_trigger()

template<typename... Ts>

Trigger< std::span< const uint8_t >, modbus::ExceptionCode > * esphome::modbus_client::ClientActionBase< Ts >::get_error_trigger ( )

inline

Definition at line 23 of file modbus_client.h.

◆ get_no_response_trigger()

template<typename... Ts>

Trigger< std::span< const uint8_t > > * esphome::modbus_client::ClientActionBase< Ts >::get_no_response_trigger ( )

inline

Definition at line 24 of file modbus_client.h.

◆ get_not_sent_trigger()

template<typename... Ts>

Trigger< std::span< const uint8_t > > * esphome::modbus_client::ClientActionBase< Ts >::get_not_sent_trigger ( )

inline

Definition at line 25 of file modbus_client.h.

◆ on_error()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::on_error	(	std::span< const uint8_t >	request_pdu,
		modbus::ExceptionCode	exception_code )

inlineoverridevirtual

A Modbus exception reply.

Lives here beside its trigger so every action subclass gets the pairing: register_client_action() wires on_error for all of them, so a derived class must not have to remember the override.

Reimplemented from esphome::modbus::ModbusClientDevice.

Definition at line 45 of file modbus_client.h.

◆ on_no_response()

template<typename... Ts>

bool esphome::modbus_client::ClientActionBase< Ts >::on_no_response ( std::span< const uint8_t > request_pdu )

inlineoverridevirtual

No reply within send_wait_time.

Run the on_no_response actions (empty in the pure-lambda form), then let the retry lambda, if set, decide whether the hub re-queues the frame (true = retry). The two coexist: a then: automation can also carry a retry lambda. No lambda = no retry.

Reimplemented from esphome::modbus::ModbusClientDevice.

Definition at line 51 of file modbus_client.h.

◆ on_not_sent()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::on_not_sent ( std::span< const uint8_t > request_pdu )

inlineoverridevirtual

Never reached the wire, from either of two sources.

The hub calls this for a request it accepted and then dropped, which happens only when clear_tx_queue_for_address() retires it - a modbus device going offline, say. Everything the hub refuses at the door instead returns false from queue_pdu() with no callback at all, so send_or_resolve_() below turns those into this same callback: a full queue, a duplicate write, or an empty PDU from a rejecting builder.

Reimplemented from esphome::modbus::ModbusClientDevice.

Definition at line 41 of file modbus_client.h.

◆ on_sent()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::on_sent ( std::span< const uint8_t > request_pdu )

inlineoverridevirtual

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.

request_pdu is the PDU sent (function code + data).

Reimplemented from esphome::modbus::ModbusClientDevice.

Definition at line 35 of file modbus_client.h.

◆ play_complex()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::play_complex ( const Ts &... x )

inlineoverridevirtual

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.

Reimplemented from esphome::Action< Ts... >.

Definition at line 59 of file modbus_client.h.

◆ send_or_resolve_()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::send_or_resolve_ ( std::span< const uint8_t > pdu )

inlineprotected

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).

Every send still gets exactly one outcome (a broadcast (address 0) is the exception - never answered, it resolves through on_sent() alone), so resolve refusals here via on_not_sent. Takes a span, not a PduBuffer: the builders return right-sized buffers (a read PDU is 5 bytes), and a PduBuffer parameter would widen each one to the 253-byte maximum just to cross the call.

Definition at line 71 of file modbus_client.h.

◆ set_retry()

template<typename... Ts>

void esphome::modbus_client::ClientActionBase< Ts >::set_retry ( retry_func_t f )

inline

Definition at line 31 of file modbus_client.h.

◆ TEMPLATABLE_VALUE()

template<typename... Ts>

esphome::modbus_client::ClientActionBase< Ts >::TEMPLATABLE_VALUE	(	uint8_t	,
		target_address	)

Trigger<std::span<const uint8_t> > esphome::modbus_client::ClientActionBase< Ts >::sent_trigger_

protected

Definition at line 76 of file modbus_client.h.

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

esphome/components/modbus_client/modbus_client.h

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ retry_func_t

Member Function Documentation

◆ get_error_trigger()

◆ get_no_response_trigger()

◆ get_not_sent_trigger()

◆ on_error()

◆ on_no_response()

◆ on_not_sent()

◆ on_sent()

◆ play_complex()

◆ send_or_resolve_()

◆ set_retry()

◆ TEMPLATABLE_VALUE()

Field Documentation

◆ error_trigger_

◆ no_response_trigger_

◆ not_sent_trigger_

◆ retry_func_

◆ sent_trigger_