Modbus/TCP client. More...

#include "core/net.h"
#include "modbus/modbus_common.h"
#include "core/crypto.h"
#include "tls.h"

Data Structures
struct	_ModbusClientContext
	Modbus/TCP client context. More...

Macros
#define	MODBUS_CLIENT_SUPPORT ENABLED

#define	MODBUS_CLIENT_TLS_SUPPORT DISABLED

#define	MODBUS_CLIENT_DEFAULT_TIMEOUT 20000

#define	MODBUS_CLIENT_TLS_TX_BUFFER_SIZE 2048

#define	MODBUS_CLIENT_TLS_RX_BUFFER_SIZE 2048

#define	MODBUS_CLIENT_PRIVATE_CONTEXT

#define	ModbusClientContext struct _ModbusClientContext

Typedefs
typedef error_t(*	ModbusClientTlsInitCallback) (ModbusClientContext context, TlsContext tlsContext)
	TLS initialization callback function. More...

Enumerations
enum	ModbusClientState { MODBUS_CLIENT_STATE_DISCONNECTED = 0 , MODBUS_CLIENT_STATE_CONNECTING = 1 , MODBUS_CLIENT_STATE_CONNECTED = 2 , MODBUS_CLIENT_STATE_SENDING = 3 , MODBUS_CLIENT_STATE_RECEIVING = 4 , MODBUS_CLIENT_STATE_COMPLETE = 5 , MODBUS_CLIENT_STATE_DISCONNECTING = 6 }
	Modbus/TCP client states. More...

Functions
error_t	modbusClientInit (ModbusClientContext *context)
	Initialize Modbus/TCP client context. More...

error_t	modbusClientRegisterTlsInitCallback (ModbusClientContext *context, ModbusClientTlsInitCallback callback)
	Register TLS initialization callback function. More...

error_t	modbusClientSetTimeout (ModbusClientContext *context, systime_t timeout)
	Set timeout value for blocking operations. More...

error_t	modbusClientSetUnitId (ModbusClientContext *context, uint8_t unitId)
	Set unit identifier. More...

error_t	modbusClientBindToInterface (ModbusClientContext context, NetInterface interface)
	Bind the Modbus/TCP client to a particular network interface. More...

error_t	modbusClientConnect (ModbusClientContext context, const IpAddr serverIpAddr, uint16_t serverPort)
	Establish connection with the Modbus/TCP server. More...

error_t	modbusClientReadCoils (ModbusClientContext context, uint16_t address, uint_t quantity, uint8_t value)
	Read coils. More...

error_t	modbusClientReadDiscreteInputs (ModbusClientContext context, uint16_t address, uint_t quantity, uint8_t value)
	Read discrete inputs. More...

error_t	modbusClientReadHoldingRegs (ModbusClientContext context, uint16_t address, uint_t quantity, uint16_t value)
	Read holding registers. More...

error_t	modbusClientReadInputRegs (ModbusClientContext context, uint16_t address, uint_t quantity, uint16_t value)
	Read input registers. More...

error_t	modbusClientWriteSingleCoil (ModbusClientContext *context, uint16_t address, bool_t value)
	Write single coil. More...

error_t	modbusClientWriteSingleReg (ModbusClientContext *context, uint16_t address, uint16_t value)
	Write single register. More...

error_t	modbusClientWriteMultipleCoils (ModbusClientContext context, uint16_t address, uint_t quantity, const uint8_t value)
	Write multiple coils. More...

error_t	modbusClientWriteMultipleRegs (ModbusClientContext context, uint16_t address, uint_t quantity, const uint16_t value)
	Write multiple registers. More...

error_t	modbusClientMaskWriteReg (ModbusClientContext *context, uint16_t address, uint16_t andMask, uint16_t orMask)
	Apply AND/OR bitmask to a register. More...

error_t	modbusClientReadWriteMultipleRegs (ModbusClientContext context, uint16_t readAddress, uint_t readQuantity, uint16_t readValue, uint16_t writeAddress, uint_t writeQuantity, const uint16_t *writeValue)
	Read/write multiple registers. More...

error_t	modbusClientGetExceptionCode (ModbusClientContext context, ModbusExceptionCode exceptionCode)
	Retrieve exception code. More...

error_t	modbusClientDisconnect (ModbusClientContext *context)
	Gracefully disconnect from the Modbus/TCP server. More...

error_t	modbusClientClose (ModbusClientContext *context)
	Close the connection with the Modbus/TCP server. More...

void	modbusClientDeinit (ModbusClientContext *context)
	Release Modbus/TCP client context. More...

Detailed Description

Modbus/TCP client.

License

SPDX-License-Identifier: GPL-2.0-or-later

This file is part of CycloneTCP Open.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Author: Oryx Embedded SARL (www.oryx-embedded.com)

Version: 2.4.0

Definition in file modbus_client.h.

Macro Definition Documentation

◆ MODBUS_CLIENT_DEFAULT_TIMEOUT

#define MODBUS_CLIENT_DEFAULT_TIMEOUT 20000

Definition at line 54 of file modbus_client.h.

◆ MODBUS_CLIENT_PRIVATE_CONTEXT

#define MODBUS_CLIENT_PRIVATE_CONTEXT

Definition at line 75 of file modbus_client.h.

◆ MODBUS_CLIENT_SUPPORT

#define MODBUS_CLIENT_SUPPORT ENABLED

Definition at line 40 of file modbus_client.h.

◆ MODBUS_CLIENT_TLS_RX_BUFFER_SIZE

#define MODBUS_CLIENT_TLS_RX_BUFFER_SIZE 2048

Definition at line 68 of file modbus_client.h.

◆ MODBUS_CLIENT_TLS_SUPPORT

#define MODBUS_CLIENT_TLS_SUPPORT DISABLED

Definition at line 47 of file modbus_client.h.

◆ MODBUS_CLIENT_TLS_TX_BUFFER_SIZE

#define MODBUS_CLIENT_TLS_TX_BUFFER_SIZE 2048

Definition at line 61 of file modbus_client.h.

◆ ModbusClientContext

#define ModbusClientContext struct _ModbusClientContext

Definition at line 86 of file modbus_client.h.

Typedef Documentation

◆ ModbusClientTlsInitCallback

typedef error_t(* ModbusClientTlsInitCallback) (ModbusClientContext *context, TlsContext *tlsContext)

TLS initialization callback function.

Definition at line 117 of file modbus_client.h.

Enumeration Type Documentation

◆ ModbusClientState

enum ModbusClientState

Modbus/TCP client states.

Enumerator
MODBUS_CLIENT_STATE_DISCONNECTED
MODBUS_CLIENT_STATE_CONNECTING
MODBUS_CLIENT_STATE_CONNECTED
MODBUS_CLIENT_STATE_SENDING
MODBUS_CLIENT_STATE_RECEIVING
MODBUS_CLIENT_STATE_COMPLETE
MODBUS_CLIENT_STATE_DISCONNECTING

Definition at line 98 of file modbus_client.h.

Function Documentation

◆ modbusClientBindToInterface()

error_t modbusClientBindToInterface	(	ModbusClientContext *	context,
		NetInterface *	interface
	)

Bind the Modbus/TCP client to a particular network interface.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	interface	Network interface to be used

Returns: Error code

Definition at line 164 of file modbus_client.c.

◆ modbusClientClose()

error_t modbusClientClose ( ModbusClientContext * context )

Close the connection with the Modbus/TCP server.

Parameters

[in] context Pointer to the Modbus/TCP client context

Returns: Error code

Definition at line 1041 of file modbus_client.c.

◆ modbusClientConnect()

error_t modbusClientConnect	(	ModbusClientContext *	context,
		const IpAddr *	serverIpAddr,
		uint16_t	serverPort
	)

Establish connection with the Modbus/TCP server.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	serverIpAddr	IP address of the server to connect to
[in]	serverPort	TCP port number that will be used

Returns: Error code

Definition at line 187 of file modbus_client.c.

◆ modbusClientDeinit()

void modbusClientDeinit ( ModbusClientContext * context )

Release Modbus/TCP client context.

Parameters

[in] context Pointer to the Modbus/TCP client context

Definition at line 1062 of file modbus_client.c.

◆ modbusClientDisconnect()

error_t modbusClientDisconnect ( ModbusClientContext * context )

Gracefully disconnect from the Modbus/TCP server.

Parameters

[in] context Pointer to the Modbus/TCP client context

Returns: Error code

Definition at line 964 of file modbus_client.c.

◆ modbusClientGetExceptionCode()

error_t modbusClientGetExceptionCode	(	ModbusClientContext *	context,
		ModbusExceptionCode *	exceptionCode
	)

Retrieve exception code.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[out]	exceptionCode	Exception code

Returns: Error code

Definition at line 943 of file modbus_client.c.

◆ modbusClientInit()

error_t modbusClientInit ( ModbusClientContext * context )

Initialize Modbus/TCP client context.

Parameters

[in] context Pointer to the Modbus/TCP client context

Returns: Error code

Definition at line 51 of file modbus_client.c.

◆ modbusClientMaskWriteReg()

error_t modbusClientMaskWriteReg	(	ModbusClientContext *	context,
		uint16_t	address,
		uint16_t	andMask,
		uint16_t	orMask
	)

Apply AND/OR bitmask to a register.

This function code is used to modify the contents of a specified holding register using a combination of an AND mask, an OR mask, and the register's current contents. The function can be used to set or clear individual bits in the register

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the holding register
[in]	andMask	AND bitmask
[in]	orMask	OR bitmask

Returns: Error code

Definition at line 810 of file modbus_client.c.

◆ modbusClientReadCoils()

error_t modbusClientReadCoils	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		uint8_t *	value
	)

Read coils.

This function code is used to read from 1 to 2000 contiguous status of coils in a remote device. The request specifies the starting address and the number of coils

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the first coil
[in]	quantity	Number of coils
[out]	value	Value of the discrete outputs

Returns: Error code

Definition at line 279 of file modbus_client.c.

◆ modbusClientReadDiscreteInputs()

error_t modbusClientReadDiscreteInputs	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		uint8_t *	value
	)

Read discrete inputs.

This function code is used to read from 1 to 2000 contiguous status of discrete inputs in a remote device. The request specifies the starting address and the number of inputs

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the first input
[in]	quantity	Number of inputs
[out]	value	Value of the discrete inputs

Returns: Error code

Definition at line 347 of file modbus_client.c.

◆ modbusClientReadHoldingRegs()

error_t modbusClientReadHoldingRegs	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		uint16_t *	value
	)

Read holding registers.

This function code is used to read the contents of a contiguous block of holding registers in a remote device. The request specifies the starting register address and the number of registers

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Starting register address
[in]	quantity	Number of registers
[out]	value	Value of the holding registers

Returns: Error code

Definition at line 415 of file modbus_client.c.

◆ modbusClientReadInputRegs()

error_t modbusClientReadInputRegs	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		uint16_t *	value
	)

Read input registers.

This function code is used to read from 1 to 125 contiguous input registers in a remote device. The request specifies the starting register address and the number of registers

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Starting register address
[in]	quantity	Number of registers
[out]	value	Value of the input registers

Returns: Error code

Definition at line 483 of file modbus_client.c.

◆ modbusClientReadWriteMultipleRegs()

error_t modbusClientReadWriteMultipleRegs	(	ModbusClientContext *	context,
		uint16_t	readAddress,
		uint_t	readQuantity,
		uint16_t *	readValue,
		uint16_t	writeAddress,
		uint_t	writeQuantity,
		const uint16_t *	writeValue
	)

Read/write multiple registers.

This function code performs a combination of one read operation and one write operation in a single Modbus transaction. The write operation is performed before the read

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	readAddress	Address of the first holding registers to be read
[in]	readQuantity	Number of holding registers to be read
[out]	readValue	Value of the holding registers (read operation)
[in]	writeAddress	Address of the first holding registers to be written
[in]	writeQuantity	Number of holding registers to be written
[in]	writeValue	Value of the holding registers (write operation)

Returns: Error code

Definition at line 877 of file modbus_client.c.

◆ modbusClientRegisterTlsInitCallback()

error_t modbusClientRegisterTlsInitCallback	(	ModbusClientContext *	context,
		ModbusClientTlsInitCallback	callback
	)

Register TLS initialization callback function.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	callback	TLS initialization callback function

Returns: Error code

Definition at line 98 of file modbus_client.c.

◆ modbusClientSetTimeout()

error_t modbusClientSetTimeout	(	ModbusClientContext *	context,
		systime_t	timeout
	)

Set timeout value for blocking operations.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	timeout	Timeout value, in milliseconds

Returns: Error code

Definition at line 122 of file modbus_client.c.

◆ modbusClientSetUnitId()

error_t modbusClientSetUnitId	(	ModbusClientContext *	context,
		uint8_t	unitId
	)

Set unit identifier.

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	unitId	Identifier of the remote slave

Returns: Error code

Definition at line 143 of file modbus_client.c.

◆ modbusClientWriteMultipleCoils()

error_t modbusClientWriteMultipleCoils	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		const uint8_t *	value
	)

Write multiple coils.

This function code is used to force each coil in a sequence of coils to either ON or OFF in a remote device. The request specifies the starting address, the number of outputs and the requested ON/OFF states

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the first coil to be forced
[in]	quantity	Number of coils
[in]	value	Value of the discrete outputs

Returns: Error code

Definition at line 673 of file modbus_client.c.

◆ modbusClientWriteMultipleRegs()

error_t modbusClientWriteMultipleRegs	(	ModbusClientContext *	context,
		uint16_t	address,
		uint_t	quantity,
		const uint16_t *	value
	)

Write multiple registers.

This function code is used to write a block of contiguous registers (1 to 123 registers) in a remote device. The request specifies the starting address, the number of registers and the requested written values

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Starting register address
[in]	quantity	Number of registers
[in]	value	Value of the holding registers

Returns: Error code

Definition at line 741 of file modbus_client.c.

◆ modbusClientWriteSingleCoil()

error_t modbusClientWriteSingleCoil	(	ModbusClientContext *	context,
		uint16_t	address,
		bool_t	value
	)

Write single coil.

This function code is used to write a single output to either ON or OFF in a remote device. The request specifies the address of the coil to be forced and the requested ON/OFF state

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the coil to be forced
[in]	value	Value of the discrete output

Returns: Error code

Definition at line 550 of file modbus_client.c.

◆ modbusClientWriteSingleReg()

error_t modbusClientWriteSingleReg	(	ModbusClientContext *	context,
		uint16_t	address,
		uint16_t	value
	)

Write single register.

This function code is used to write a single holding register in a remote device. The request specifies the address of the register to be written and the register value

Parameters

[in]	context	Pointer to the Modbus/TCP client context
[in]	address	Address of the register to be written
[in]	value	Register value

Returns: Error code

Definition at line 611 of file modbus_client.c.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

License

Macro Definition Documentation

◆ MODBUS_CLIENT_DEFAULT_TIMEOUT

◆ MODBUS_CLIENT_PRIVATE_CONTEXT

◆ MODBUS_CLIENT_SUPPORT

◆ MODBUS_CLIENT_TLS_RX_BUFFER_SIZE

◆ MODBUS_CLIENT_TLS_SUPPORT

◆ MODBUS_CLIENT_TLS_TX_BUFFER_SIZE

◆ ModbusClientContext

Typedef Documentation

◆ ModbusClientTlsInitCallback

Enumeration Type Documentation

◆ ModbusClientState

Function Documentation

◆ modbusClientBindToInterface()

◆ modbusClientClose()

◆ modbusClientConnect()

◆ modbusClientDeinit()

◆ modbusClientDisconnect()

◆ modbusClientGetExceptionCode()

◆ modbusClientInit()

◆ modbusClientMaskWriteReg()

◆ modbusClientReadCoils()

◆ modbusClientReadDiscreteInputs()

◆ modbusClientReadHoldingRegs()

◆ modbusClientReadInputRegs()

◆ modbusClientReadWriteMultipleRegs()

◆ modbusClientRegisterTlsInitCallback()

◆ modbusClientSetTimeout()

◆ modbusClientSetUnitId()

◆ modbusClientWriteMultipleCoils()

◆ modbusClientWriteMultipleRegs()

◆ modbusClientWriteSingleCoil()

◆ modbusClientWriteSingleReg()