Software / API Bindings / C/C++ for Microcontrollers / API Reference and Examples / Bricklets / RS485 Bricklet

C/C++ for Microcontrollers - RS485 Bricklet¶

This is the description of the C/C++ for Microcontrollers API bindings for the RS485 Bricklet. General information and technical specifications for the RS485 Bricklet are summarized in its hardware description.

An installation guide for the C/C++ for Microcontrollers API bindings is part of their general description.

Examples¶

The example code below is Public Domain (CC0 1.0).

Loopback¶

Download (example_loopback.c)

// This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.

#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_rs485.h"

// For this example connect the RX+/- pins to TX+/- pins on the same Bricklet
// and configure the DIP switch on the Bricklet to full-duplex mode

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

static char buffer[5] = {0}; // +1 for the null terminator

// Callback function for read callback
static void read_handler(TF_RS485 *device, char *message, uint16_t message_length,
                         void *user_data) {
    (void)device; (void)user_data; // avoid unused parameter warning

    message[message_length] = '\0';

    tf_hal_printf("Message: \"%s\"\n", message);
}

static TF_RS485 rs485;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_rs485_create(&rs485, NULL, hal), "create device object");

    // Enable full-duplex mode
    check(tf_rs485_set_rs485_configuration(&rs485, 115200, TF_RS485_PARITY_NONE,
                                           TF_RS485_STOPBITS_1, TF_RS485_WORDLENGTH_8,
                                           TF_RS485_DUPLEX_FULL), "call set_rs485_configuration");

    // Register read callback to function read_handler
    tf_rs485_register_read_callback(&rs485,
                                    read_handler,
                                    buffer,
                                    NULL);

    // Enable read callback
    check(tf_rs485_enable_read_callback(&rs485), "call enable_read_callback");

    // Write "test" string
    char write_buffer[] = {'t', 'e', 's', 't'};
    uint16_t written;
    tf_rs485_write(&rs485, write_buffer, sizeof(write_buffer), &written);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

Modbus Slave¶

Download (example_modbus_slave.c)

// This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.

#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_rs485.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

static uint8_t received_request_id = 0;
static bool register_address_valid = false;

// Callback function for Modbus slave write single register request callback
static void modbus_slave_write_single_register_request_handler(TF_RS485 *device, uint8_t request_id,
                                                               uint32_t register_address,
                                                               uint16_t register_value,
                                                               void *user_data) {
    (void)device; (void)user_data; // avoid unused parameter warning

    tf_hal_printf("Request ID: %I8u\n", request_id);
    tf_hal_printf("Register Address: %I32u\n", register_address);
    tf_hal_printf("Register Value: %I16u\n", register_value);
    tf_hal_printf("\n");

    received_request_id = request_id;
    register_address_valid = register_address == 42;

    if (!register_address_valid) {
        tf_hal_printf("Error: Invalid register address\n");
    }
}

static TF_RS485 rs485;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_rs485_create(&rs485, NULL, hal), "create device object");

    // Set operating mode to Modbus RTU slave
    check(tf_rs485_set_mode(&rs485, TF_RS485_MODE_MODBUS_SLAVE_RTU), "call set_mode");

    // Modbus specific configuration:
    // - slave address = 17
    // - master request timeout = 0ms (unused in slave mode)
    check(tf_rs485_set_modbus_configuration(&rs485, 17,
                                            0), "call set_modbus_configuration");

    // Register Modbus slave write single register request callback to function
    // modbus_slave_write_single_register_request_handler
    tf_rs485_register_modbus_slave_write_single_register_request_callback(&rs485,
                                                                          modbus_slave_write_single_register_request_handler,
                                                                          NULL);
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    // Polling with 0 will process one packet at most, so we can't miss a request.
    tf_hal_callback_tick(hal, 0);

    if(received_request_id == 0) {
        // We didn't receive a request.
        return;
    }

    if(!register_address_valid) {
        tf_rs485_modbus_slave_report_exception(&rs485, received_request_id, TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS);
    } else {
        tf_rs485_modbus_slave_answer_write_single_register_request(&rs485, received_request_id);
    }

    // Make sure we respond to the request only once.
    received_request_id = 0;
}

Modbus Master¶

Download (example_modbus_master.c)

// This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.

#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_rs485.h"

void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);

static void log_exception(int8_t exception_code) {
    if (exception_code == TF_RS485_EXCEPTION_CODE_TIMEOUT) {
        tf_hal_printf("Exception Code: Timeout\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_SUCCESS) {
        tf_hal_printf("Exception Code: Success\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION) {
        tf_hal_printf("Exception Code: Illegal Function\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS) {
        tf_hal_printf("Exception Code: Illegal Data Address\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE) {
        tf_hal_printf("Exception Code: Illegal Data Value\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE) {
        tf_hal_printf("Exception Code: Slave Device Failure\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE) {
        tf_hal_printf("Exception Code: Acknowledge\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY) {
        tf_hal_printf("Exception Code: Slave Device Busy\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR) {
        tf_hal_printf("Exception Code: Memory Parity Error\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE) {
        tf_hal_printf("Exception Code: Gateway Path Unavailable\n");
    } else if (exception_code == TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND) {
        tf_hal_printf("Exception Code: Gateway Target Device Failed To Respond\n");
    }
}

// Callback function for Modbus master write single register response callback
static void modbus_master_write_single_register_response_handler(TF_RS485 *device, uint8_t request_id,
                                                                 int8_t exception_code,
                                                                 void *user_data) {
    (void)device; // avoid unused parameter warning

    uint8_t expected_request_id = *(uint8_t *)user_data;

    tf_hal_printf("Request ID: %I8u\n", request_id);

    if(exception_code != TF_RS485_EXCEPTION_CODE_SUCCESS) {
        log_exception(exception_code);
    }

    if (request_id != expected_request_id) {
        tf_hal_printf("Error: Unexpected request ID\n");
    }

    tf_hal_printf("\n");
}

static TF_RS485 rs485;
static uint8_t expected_request_id = 0;

void example_setup(TF_HAL *hal) {
    // Create device object
    check(tf_rs485_create(&rs485, NULL, hal), "create device object");

    // Set operating mode to Modbus RTU master
    check(tf_rs485_set_mode(&rs485, TF_RS485_MODE_MODBUS_MASTER_RTU), "call set_mode");

    // Modbus specific configuration:
    // - slave address = 1 (unused in master mode)
    // - master request timeout = 1000ms
    check(tf_rs485_set_modbus_configuration(&rs485, 1,
                                            1000), "call set_modbus_configuration");

    // Register Modbus master write single register response callback to function
    // modbus_master_write_single_register_response_handler
    tf_rs485_register_modbus_master_write_single_register_response_callback(&rs485,
                                                                            modbus_master_write_single_register_response_handler,
                                                                            &expected_request_id);

    // Write 65535 to register 42 of slave 17
    check(tf_rs485_modbus_master_write_single_register(&rs485, 17, 42,
                                                       65535, &expected_request_id), "call modbus_master_write_single_register");
}

void example_loop(TF_HAL *hal) {
    // Poll for callbacks
    tf_hal_callback_tick(hal, 0);
}

API¶

Most functions of the C/C++ bindings for microcontrollers return an error code (e_code).

Possible error codes are:

TF_E_OK = 0
TF_E_TIMEOUT = -1
TF_E_INVALID_PARAMETER = -2
TF_E_NOT_SUPPORTED = -3
TF_E_UNKNOWN_ERROR_CODE = -4
TF_E_STREAM_OUT_OF_SYNC = -5
TF_E_INVALID_CHAR_IN_UID = -6
TF_E_UID_TOO_LONG = -7
TF_E_UID_OVERFLOW = -8
TF_E_TOO_MANY_DEVICES = -9
TF_E_DEVICE_NOT_FOUND = -10
TF_E_WRONG_DEVICE_TYPE = -11
TF_E_LOCKED = -12
TF_E_PORT_NOT_FOUND = -13

(as defined in errors.h) as well as the errors returned from the hardware abstraction layer (HAL) that is used.

Use :cpp:func`tf_hal_strerror` (defined in the HAL's header file) to get an error string for an error code.

Data returned from the device, when a getter is called, is handled via output parameters. These parameters are labeled with the ret_ prefix. The bindings will not write to an output parameter if NULL or nullptr is passed. This can be used to ignore outputs that you are not interested in.

None of the functions listed below are thread-safe. See the API bindings description for details.

Basic Functions¶

int tf_rs485_create(TF_RS485 *rs485, const char *uid_or_port_name, TF_HAL *hal)¶

Parameters:	rs485 – Type: TF_RS485 * uid – Type: const char * hal – Type: TF_HAL *
Returns:	e_code – Type: int

Creates the device object rs485 with the optional unique device ID or port name uid_or_port_name and adds it to the HAL hal:

TF_RS485 rs485;
tf_rs485_create(&rs485, NULL, &hal);

Normally uid_or_port_name can stay NULL. For more details about this see section UID or Port Name.

int tf_rs485_destroy(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Removes the device object rs485 from its HAL and destroys it. The device object cannot be used anymore afterwards.

int tf_rs485_write(TF_RS485 *rs485, const char *message, uint16_t message_length, uint16_t *ret_message_written)¶

Parameters:	rs485 – Type: TF_RS485 * message – Type: const char * message_length – Type: uint16_t
Output Parameters:	ret_message_written – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

Writes characters to the RS485 interface. The characters can be binary data, ASCII or similar is not necessary.

The return value is the number of characters that were written.

See tf_rs485_set_rs485_configuration() for configuration possibilities regarding baudrate, parity and so on.

int tf_rs485_read(TF_RS485 *rs485, uint16_t length, char *ret_message, uint16_t *ret_message_length)¶

Parameters:	rs485 – Type: TF_RS485 * length – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Output Parameters:	ret_message – Type: char * ret_message_length – Type: uint16_t
Returns:	e_code – Type: int

Returns up to length characters from receive buffer.

Instead of polling with this function, you can also use callbacks. But note that this function will return available data only when the read callback is disabled. See tf_rs485_enable_read_callback() and Read Low Level callback.

int tf_rs485_set_rs485_configuration(TF_RS485 *rs485, uint32_t baudrate, uint8_t parity, uint8_t stopbits, uint8_t wordlength, uint8_t duplex)¶

Parameters:	rs485 – Type: TF_RS485 * baudrate – Type: uint32_t, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 parity – Type: uint8_t, Range: See constants, Default: 0 stopbits – Type: uint8_t, Range: See constants, Default: 1 wordlength – Type: uint8_t, Range: See constants, Default: 8 duplex – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Sets the configuration for the RS485 communication.

The following constants are available for this function:

For parity:

TF_RS485_PARITY_NONE = 0
TF_RS485_PARITY_ODD = 1
TF_RS485_PARITY_EVEN = 2

For stopbits:

TF_RS485_STOPBITS_1 = 1
TF_RS485_STOPBITS_2 = 2

For wordlength:

TF_RS485_WORDLENGTH_5 = 5
TF_RS485_WORDLENGTH_6 = 6
TF_RS485_WORDLENGTH_7 = 7
TF_RS485_WORDLENGTH_8 = 8

For duplex:

TF_RS485_DUPLEX_HALF = 0
TF_RS485_DUPLEX_FULL = 1

int tf_rs485_get_rs485_configuration(TF_RS485 *rs485, uint32_t *ret_baudrate, uint8_t *ret_parity, uint8_t *ret_stopbits, uint8_t *ret_wordlength, uint8_t *ret_duplex)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_baudrate – Type: uint32_t, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 ret_parity – Type: uint8_t, Range: See constants, Default: 0 ret_stopbits – Type: uint8_t, Range: See constants, Default: 1 ret_wordlength – Type: uint8_t, Range: See constants, Default: 8 ret_duplex – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_rs485_configuration().

The following constants are available for this function:

For ret_parity:

TF_RS485_PARITY_NONE = 0
TF_RS485_PARITY_ODD = 1
TF_RS485_PARITY_EVEN = 2

For ret_stopbits:

TF_RS485_STOPBITS_1 = 1
TF_RS485_STOPBITS_2 = 2

For ret_wordlength:

TF_RS485_WORDLENGTH_5 = 5
TF_RS485_WORDLENGTH_6 = 6
TF_RS485_WORDLENGTH_7 = 7
TF_RS485_WORDLENGTH_8 = 8

For ret_duplex:

TF_RS485_DUPLEX_HALF = 0
TF_RS485_DUPLEX_FULL = 1

int tf_rs485_set_modbus_configuration(TF_RS485 *rs485, uint8_t slave_address, uint32_t master_request_timeout)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [1 to 247], Default: 1 master_request_timeout – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 1000
Returns:	e_code – Type: int

Sets the configuration for the RS485 Modbus communication. Available options:

Slave Address: Address to be used as the Modbus slave address in Modbus slave mode. Valid Modbus slave address range is 1 to 247.
Master Request Timeout: Specifies how long the master should wait for a response from a slave when in Modbus master mode.

int tf_rs485_get_modbus_configuration(TF_RS485 *rs485, uint8_t *ret_slave_address, uint32_t *ret_master_request_timeout)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_slave_address – Type: uint8_t, Range: [1 to 247], Default: 1 ret_master_request_timeout – Type: uint32_t, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 1000
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_modbus_configuration().

int tf_rs485_set_mode(TF_RS485 *rs485, uint8_t mode)¶

Parameters:	rs485 – Type: TF_RS485 * mode – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Sets the mode of the Bricklet in which it operates. Available options are

RS485,
Modbus Master RTU and
Modbus Slave RTU.

The following constants are available for this function:

For mode:

TF_RS485_MODE_RS485 = 0
TF_RS485_MODE_MODBUS_MASTER_RTU = 1
TF_RS485_MODE_MODBUS_SLAVE_RTU = 2

int tf_rs485_get_mode(TF_RS485 *rs485, uint8_t *ret_mode)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_mode – Type: uint8_t, Range: See constants, Default: 0
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_mode().

The following constants are available for this function:

For ret_mode:

TF_RS485_MODE_RS485 = 0
TF_RS485_MODE_MODBUS_MASTER_RTU = 1
TF_RS485_MODE_MODBUS_SLAVE_RTU = 2

Advanced Functions¶

int tf_rs485_set_communication_led_config(TF_RS485 *rs485, uint8_t config)¶

Parameters:	rs485 – Type: TF_RS485 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Sets the communication LED configuration. By default the LED shows RS485 communication traffic by flickering.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

For config:

TF_RS485_COMMUNICATION_LED_CONFIG_OFF = 0
TF_RS485_COMMUNICATION_LED_CONFIG_ON = 1
TF_RS485_COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3

int tf_rs485_get_communication_led_config(TF_RS485 *rs485, uint8_t *ret_config)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_communication_led_config()

The following constants are available for this function:

For ret_config:

TF_RS485_COMMUNICATION_LED_CONFIG_OFF = 0
TF_RS485_COMMUNICATION_LED_CONFIG_ON = 1
TF_RS485_COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3

int tf_rs485_set_error_led_config(TF_RS485 *rs485, uint8_t config)¶

Parameters:	rs485 – Type: TF_RS485 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Sets the error LED configuration.

By default the error LED turns on if there is any error (see Error Count callback). If you call this function with the SHOW ERROR option again, the LED will turn off until the next error occurs.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is off.

The following constants are available for this function:

For config:

TF_RS485_ERROR_LED_CONFIG_OFF = 0
TF_RS485_ERROR_LED_CONFIG_ON = 1
TF_RS485_ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_ERROR_LED_CONFIG_SHOW_ERROR = 3

int tf_rs485_get_error_led_config(TF_RS485 *rs485, uint8_t *ret_config)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_error_led_config().

The following constants are available for this function:

For ret_config:

TF_RS485_ERROR_LED_CONFIG_OFF = 0
TF_RS485_ERROR_LED_CONFIG_ON = 1
TF_RS485_ERROR_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_ERROR_LED_CONFIG_SHOW_ERROR = 3

int tf_rs485_set_buffer_config(TF_RS485 *rs485, uint16_t send_buffer_size, uint16_t receive_buffer_size)¶

Parameters:	rs485 – Type: TF_RS485 * send_buffer_size – Type: uint16_t, Unit: 1 B, Range: [2¹⁰ to 9216], Default: 5120 receive_buffer_size – Type: uint16_t, Unit: 1 B, Range: [2¹⁰ to 9216], Default: 5120
Returns:	e_code – Type: int

Sets the send and receive buffer size in byte. In sum there is 10240 byte (10KiB) buffer available and the minimum buffer size is 1024 byte (1KiB) for both.

The current buffer content is lost if this function is called.

The send buffer holds data that was given by tf_rs485_write() and could not be written yet. The receive buffer holds data that is received through RS485 but could not yet be send to the user, either by tf_rs485_read() or through Read Low Level callback.

int tf_rs485_get_buffer_config(TF_RS485 *rs485, uint16_t *ret_send_buffer_size, uint16_t *ret_receive_buffer_size)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_send_buffer_size – Type: uint16_t, Unit: 1 B, Range: [2¹⁰ to 9216], Default: 5120 ret_receive_buffer_size – Type: uint16_t, Unit: 1 B, Range: [2¹⁰ to 9216], Default: 5120
Returns:	e_code – Type: int

Returns the buffer configuration as set by tf_rs485_set_buffer_config().

int tf_rs485_get_buffer_status(TF_RS485 *rs485, uint16_t *ret_send_buffer_used, uint16_t *ret_receive_buffer_used)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_send_buffer_used – Type: uint16_t, Unit: 1 B, Range: [0 to 9216] ret_receive_buffer_used – Type: uint16_t, Unit: 1 B, Range: [0 to 9216]
Returns:	e_code – Type: int

Returns the currently used bytes for the send and received buffer.

See tf_rs485_set_buffer_config() for buffer size configuration.

int tf_rs485_get_error_count(TF_RS485 *rs485, uint32_t *ret_overrun_error_count, uint32_t *ret_parity_error_count)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_overrun_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_parity_error_count – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Returns the current number of overrun and parity errors.

int tf_rs485_get_modbus_common_error_count(TF_RS485 *rs485, uint32_t *ret_timeout_error_count, uint32_t *ret_checksum_error_count, uint32_t *ret_frame_too_big_error_count, uint32_t *ret_illegal_function_error_count, uint32_t *ret_illegal_data_address_error_count, uint32_t *ret_illegal_data_value_error_count, uint32_t *ret_slave_device_failure_error_count)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_timeout_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_checksum_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_frame_too_big_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_illegal_function_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_illegal_data_address_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_illegal_data_value_error_count – Type: uint32_t, Range: [0 to 2³² - 1] ret_slave_device_failure_error_count – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Returns the current number of errors occurred in Modbus mode.

Timeout Error Count: Number of timeouts occurred.
Checksum Error Count: Number of failures due to Modbus frame CRC16 checksum mismatch.
Frame Too Big Error Count: Number of times frames were rejected because they exceeded maximum Modbus frame size which is 256 bytes.
Illegal Function Error Count: Number of errors when an unimplemented or illegal function is requested. This corresponds to Modbus exception code 1.
Illegal Data Address Error Count: Number of errors due to invalid data address. This corresponds to Modbus exception code 2.
Illegal Data Value Error Count: Number of errors due to invalid data value. This corresponds to Modbus exception code 3.
Slave Device Failure Error Count: Number of errors occurred on the slave device which were unrecoverable. This corresponds to Modbus exception code 4.

int tf_rs485_modbus_slave_report_exception(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to report a Modbus exception for a Modbus master request.

Request ID: Request ID of the request received by the slave.
Exception Code: Modbus exception code to report to the Modbus master.

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_modbus_slave_answer_read_coils_request(TF_RS485 *rs485, uint8_t request_id, const bool *coils, uint16_t coils_length)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] coils – Type: const bool * coils_length – Type: uint16_t
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to read coils.

Request ID: Request ID of the corresponding request that is being answered.
Coils: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the Modbus Slave Read Coils Request callback with the Request ID as provided by the argument of the callback.

int tf_rs485_modbus_master_read_coils(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, uint16_t count, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 2000]
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to read coils from a slave. This function creates a Modbus function code 1 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first coil to read. For backwards compatibility reasons this parameter is called Starting Address. It is not an address, but instead a coil number in the range of 1 to 65536.
Count: Number of coils to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Read Coils Response Low Level callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_read_holding_registers_request(TF_RS485 *rs485, uint8_t request_id, const uint16_t *holding_registers, uint16_t holding_registers_length)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] holding_registers – Type: const uint16_t , Range: [0 to 2¹⁶ - 1] holding_registers_length* – Type: uint16_t
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to read holding registers.

Request ID: Request ID of the corresponding request that is being answered.
Holding Registers: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the Modbus Slave Read Holding Registers Request callback with the Request ID as provided by the argument of the callback.

int tf_rs485_modbus_master_read_holding_registers(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, uint16_t count, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 125]
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to read holding registers from a slave. This function creates a Modbus function code 3 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first holding register to read. For backwards compatibility reasons this parameter is called Starting Address. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is implicit and must be omitted.
Count: Number of holding registers to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Read Holding Registers Response Low Level callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_write_single_coil_request(TF_RS485 *rs485, uint8_t request_id)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to write a single coil.

Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the Modbus Slave Write Single Coil Request callback with the Request ID as provided by the arguments of the callback.

int tf_rs485_modbus_master_write_single_coil(TF_RS485 *rs485, uint8_t slave_address, uint32_t coil_address, bool coil_value, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] coil_address – Type: uint32_t, Range: [1 to 2¹⁶] coil_value – Type: bool
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to write a single coil of a slave. This function creates a Modbus function code 5 request.

Slave Address: Address of the target Modbus slave.
Coil Address: Number of the coil to be written. For backwards compatibility reasons, this parameter is called Starting Address. It is not an address, but instead a coil number in the range of 1 to 65536.
Coil Value: Value to be written.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Write Single Coil Response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_write_single_register_request(TF_RS485 *rs485, uint8_t request_id)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to write a single register.

Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the Modbus Slave Write Single Register Request callback with the Request ID, Register Address and Register Value as provided by the arguments of the callback.

int tf_rs485_modbus_master_write_single_register(TF_RS485 *rs485, uint8_t slave_address, uint32_t register_address, uint16_t register_value, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] register_address – Type: uint32_t, Range: [1 to 2¹⁶] register_value – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to write a single holding register of a slave. This function creates a Modbus function code 6 request.

Slave Address: Address of the target Modbus slave.
Register Address: Number of the holding register to be written. For backwards compatibility reasons, this parameter is called Starting Address. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is implicit and must be omitted.
Register Value: Value to be written.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Write Single Register Response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_write_multiple_coils_request(TF_RS485 *rs485, uint8_t request_id)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to write multiple coils.

Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the Modbus Slave Write Multiple Coils Request Low Level callback with the Request ID of the callback.

int tf_rs485_modbus_master_write_multiple_coils(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, const bool *coils, uint16_t coils_length, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] coils – Type: const bool * coils_length – Type: uint16_t
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to write multiple coils of a slave. This function creates a Modbus function code 15 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first coil to write. For backwards compatibility reasons, this parameter is called Starting Address.It is not an address, but instead a coil number in the range of 1 to 65536.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Write Multiple Coils Response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_write_multiple_registers_request(TF_RS485 *rs485, uint8_t request_id)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to write multiple registers.

Request ID: Request ID of the corresponding request that is being answered.

This function must be called from the Modbus Slave Write Multiple Registers Request Low Level callback with the Request ID of the callback.

int tf_rs485_modbus_master_write_multiple_registers(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, const uint16_t *registers, uint16_t registers_length, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] registers – Type: const uint16_t , Range: [0 to 2¹⁶ - 1] registers_length* – Type: uint16_t
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to write multiple registers of a slave. This function creates a Modbus function code 16 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first holding register to write. For backwards compatibility reasons, this parameter is called Starting Address. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is implicit and must be omitted.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Write Multiple Registers Response callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_read_discrete_inputs_request(TF_RS485 *rs485, uint8_t request_id, const bool *discrete_inputs, uint16_t discrete_inputs_length)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] discrete_inputs – Type: const bool * discrete_inputs_length – Type: uint16_t
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to read discrete inputs.

Request ID: Request ID of the corresponding request that is being answered.
Discrete Inputs: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the Modbus Slave Read Discrete Inputs Request callback with the Request ID as provided by the argument of the callback.

int tf_rs485_modbus_master_read_discrete_inputs(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, uint16_t count, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 2000]
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to read discrete inputs from a slave. This function creates a Modbus function code 2 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first discrete input to read. For backwards compatibility reasons, this parameter is called Starting Address. It is not an address, but instead a discrete input number in the range of 1 to 65536. The prefix digit 1 (for discrete input) is implicit and must be omitted.
Count: Number of discrete inputs to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Read Discrete Inputs Response Low Level callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_modbus_slave_answer_read_input_registers_request(TF_RS485 *rs485, uint8_t request_id, const uint16_t *input_registers, uint16_t input_registers_length)¶

Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] input_registers – Type: const uint16_t , Range: [0 to 2¹⁶ - 1] input_registers_length* – Type: uint16_t
Returns:	e_code – Type: int

In Modbus slave mode this function can be used to answer a master request to read input registers.

Request ID: Request ID of the corresponding request that is being answered.
Input Registers: Data that is to be sent to the Modbus master for the corresponding request.

This function must be called from the Modbus Slave Read Input Registers Request callback with the Request ID as provided by the argument of the callback.

int tf_rs485_modbus_master_read_input_registers(TF_RS485 *rs485, uint8_t slave_address, uint32_t starting_address, uint16_t count, uint8_t *ret_request_id)¶

Parameters:	rs485 – Type: TF_RS485 * slave_address – Type: uint8_t, Range: [0 to 247] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 125]
Output Parameters:	ret_request_id – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

In Modbus master mode this function can be used to read input registers from a slave. This function creates a Modbus function code 4 request.

Slave Address: Address of the target Modbus slave.
Starting Address: Number of the first input register to read. For backwards compatibility reasons, this parameter is called Starting Address. It is not an address, but instead an input register number in the range of 1 to 65536. The prefix digit 3 (for input register) is implicit and must be omitted.
Count: Number of input registers to read.

Upon success the function will return a non-zero request ID which will represent the current request initiated by the Modbus master. In case of failure the returned request ID will be 0.

When successful this function will also invoke the Modbus Master Read Input Registers Response Low Level callback. In this callback the Request ID provided by the callback argument must be matched with the Request ID returned from this function to verify that the callback is indeed for a particular request.

int tf_rs485_get_spitfp_error_count(TF_RS485 *rs485, uint32_t *ret_error_count_ack_checksum, uint32_t *ret_error_count_message_checksum, uint32_t *ret_error_count_frame, uint32_t *ret_error_count_overflow)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_error_count_ack_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_message_checksum – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_frame – Type: uint32_t, Range: [0 to 2³² - 1] ret_error_count_overflow – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

ACK checksum errors,
message checksum errors,
framing errors and
overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

int tf_rs485_set_status_led_config(TF_RS485 *rs485, uint8_t config)¶

Parameters:	rs485 – Type: TF_RS485 * config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

For config:

TF_RS485_STATUS_LED_CONFIG_OFF = 0
TF_RS485_STATUS_LED_CONFIG_ON = 1
TF_RS485_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_rs485_get_status_led_config(TF_RS485 *rs485, uint8_t *ret_config)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_config – Type: uint8_t, Range: See constants, Default: 3
Returns:	e_code – Type: int

Returns the configuration as set by tf_rs485_set_status_led_config()

The following constants are available for this function:

For ret_config:

TF_RS485_STATUS_LED_CONFIG_OFF = 0
TF_RS485_STATUS_LED_CONFIG_ON = 1
TF_RS485_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
TF_RS485_STATUS_LED_CONFIG_SHOW_STATUS = 3

int tf_rs485_get_chip_temperature(TF_RS485 *rs485, int16_t *ret_temperature)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_temperature – Type: int16_t, Unit: 1 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	e_code – Type: int

Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

int tf_rs485_reset(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

int tf_rs485_get_identity(TF_RS485 *rs485, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_uid – Type: char[8] ret_connected_uid – Type: char[8] ret_position – Type: char, Range: ['a' to 'h', 'z'] ret_hardware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_firmware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_device_identifier – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

int tf_rs485_enable_read_callback(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Enables the Read Low Level callback. This will disable the Frame Readable callback.

By default the callback is disabled.

int tf_rs485_disable_read_callback(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Disables the Read Low Level callback.

By default the callback is disabled.

int tf_rs485_is_read_callback_enabled(TF_RS485 *rs485, bool *ret_enabled)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_enabled – Type: bool, Default: false
Returns:	e_code – Type: int

Returns true if the Read Low Level callback is enabled, false otherwise.

int tf_rs485_enable_error_count_callback(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Enables the Error Count callback.

By default the callback is disabled.

int tf_rs485_disable_error_count_callback(TF_RS485 *rs485)¶

Parameters:	rs485 – Type: TF_RS485 *
Returns:	e_code – Type: int

Disables the Error Count callback.

By default the callback is disabled.

int tf_rs485_is_error_count_callback_enabled(TF_RS485 *rs485, bool *ret_enabled)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_enabled – Type: bool, Default: true
Returns:	e_code – Type: int

Returns true if the Error Count callback is enabled, false otherwise.

int tf_rs485_set_frame_readable_callback_configuration(TF_RS485 *rs485, uint16_t frame_size)¶

Parameters:	rs485 – Type: TF_RS485 * frame_size – Type: uint16_t, Unit: 1 B, Range: [0 to 9216], Default: 0
Returns:	e_code – Type: int

Configures the Frame Readable callback. The frame size is the number of bytes, that have to be readable to trigger the callback. A frame size of 0 disables the callback. A frame size greater than 0 enables the callback and disables the Read Low Level callback.

By default the callback is disabled.

New in version 2.0.5 (Plugin).

int tf_rs485_get_frame_readable_callback_configuration(TF_RS485 *rs485, uint16_t *ret_frame_size)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_frame_size – Type: uint16_t, Unit: 1 B, Range: [0 to 9216], Default: 0
Returns:	e_code – Type: int

Returns the callback configuration as set by tf_rs485_set_frame_readable_callback_configuration().

New in version 2.0.5 (Plugin).

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding tf_rs485_register_*_callback function. The user_data passed to the registration function as well as the device that triggered the callback are passed to the registered callback handler.

Only one handler can be registered to a callback at the same time. To deregister a callback, call the tf_rs485_register_*_callback function with NULL as handler.

Note

Using callbacks for recurring events is preferred compared to using getters. Polling for a callback requires writing one byte only. See here Optimizing Performance.

Warning

Calling bindings function from inside a callback handler is not allowed. See here Thread safety.

int tf_rs485_register_read_low_level_callback(TF_RS485 *rs485, TF_RS485_ReadLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint16_t message_length, uint16_t message_chunk_offset, char message_chunk_data[60], void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * message_length – Type: uint16_t, Range: [0 to 2¹⁶ - 1] message_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1] message_chunk_data – Type: char[60] user_data – Type: void *

This callback is called if new data is available.

To enable this callback, use tf_rs485_enable_read_callback().

int tf_rs485_register_error_count_callback(TF_RS485 *rs485, TF_RS485_ErrorCountHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint32_t overrun_error_count, uint32_t parity_error_count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * overrun_error_count – Type: uint32_t, Range: [0 to 2³² - 1] parity_error_count – Type: uint32_t, Range: [0 to 2³² - 1] user_data – Type: void *

This callback is called if a new error occurs. It returns the current overrun and parity error count.

int tf_rs485_register_modbus_slave_read_coils_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveReadCoilsRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 2000] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read coils. The parameters are request ID of the request, the number of the first coil to be read and the number of coils to be read as received by the request. The number of the first coil is called starting address for backwards compatibility reasons. It is not an address, but instead a coil number in the range of 1 to 65536.

To send a response of this request use tf_rs485_modbus_slave_answer_read_coils_request().

int tf_rs485_register_modbus_master_read_coils_response_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterReadCoilsResponseLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, uint16_t coils_length, uint16_t coils_chunk_offset, bool coils_chunk_data[464], void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants coils_length – Type: uint16_t, Range: [0 to 2000] coils_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1] coils_chunk_data – Type: bool[464] user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to read coils.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than 0 then the number represents a Modbus exception code. If it is less than 0 then it represents other errors. For example, -1 indicates that the request timed out or that the master did not receive any valid response of the request within the master request timeout period as set by tf_rs485_set_modbus_configuration().

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_read_holding_registers_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveReadHoldingRegistersRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 125] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read holding registers. The parameters are request ID of the request, the number of the first holding register to be read and the number of holding registers to be read as received by the request. The number of the first holding register is called starting address for backwards compatibility reasons. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is omitted.

To send a response of this request use tf_rs485_modbus_slave_answer_read_holding_registers_request().

int tf_rs485_register_modbus_master_read_holding_registers_response_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterReadHoldingRegistersResponseLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, uint16_t holding_registers_length, uint16_t holding_registers_chunk_offset, uint16_t holding_registers_chunk_data[29], void *user_data)

Callback Parameters:

rs485 – Type: TF_RS485 *
request_id – Type: uint8_t, Range: [0 to 255]
exception_code – Type: int8_t, Range: See constants
holding_registers_length – Type: uint16_t, Range: [0 to 125]
holding_registers_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
holding_registers_chunk_data – Type: uint16_t[29], Range: [0 to 2¹⁶ - 1]
user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to read holding registers.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_write_single_coil_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveWriteSingleCoilRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t coil_address, bool coil_value, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] coil_address – Type: uint32_t, Range: [1 to 2¹⁶] coil_value – Type: bool user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write a single coil. The parameters are request ID of the request, the number of the coil and the value of coil to be written as received by the request. The number of the coil is called coil address for backwards compatibility reasons. It is not an address, but instead a coil number in the range of 1 to 65536.

To send a response of this request use tf_rs485_modbus_slave_answer_write_single_coil_request().

int tf_rs485_register_modbus_master_write_single_coil_response_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterWriteSingleCoilResponseHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to write a single coil.

The parameters are request ID of the request and exception code of the response.

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_write_single_register_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveWriteSingleRegisterRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t register_address, uint16_t register_value, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] register_address – Type: uint32_t, Range: [1 to 2¹⁶] register_value – Type: uint16_t, Range: [0 to 2¹⁶ - 1] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write a single holding register. The parameters are request ID of the request, the number of the holding register and the register value to be written as received by the request. The number of the holding register is called starting address for backwards compatibility reasons. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is omitted.

To send a response of this request use tf_rs485_modbus_slave_answer_write_single_register_request().

int tf_rs485_register_modbus_master_write_single_register_response_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterWriteSingleRegisterResponseHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to write a single register.

The parameters are request ID of the request and exception code of the response.

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_write_multiple_coils_request_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveWriteMultipleCoilsRequestLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t coils_length, uint16_t coils_chunk_offset, bool coils_chunk_data[440], void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] coils_length – Type: uint16_t, Range: [1 to 1968] coils_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1] coils_chunk_data – Type: bool[440] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write multiple coils. The parameters are request ID of the request, the number of the first coil and the data to be written as received by the request. The number of the first coil is called starting address for backwards compatibility reasons. It is not an address, but instead a coil number in the range of 1 to 65536.

To send a response of this request use tf_rs485_modbus_slave_answer_write_multiple_coils_request().

int tf_rs485_register_modbus_master_write_multiple_coils_response_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterWriteMultipleCoilsResponseHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to read coils.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than 0 then the number represents a Modbus exception code. If it is less than 0 then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by tf_rs485_set_modbus_configuration().

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_write_multiple_registers_request_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveWriteMultipleRegistersRequestLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t registers_length, uint16_t registers_chunk_offset, uint16_t registers_chunk_data[27], void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] registers_length – Type: uint16_t, Range: [1 to 123] registers_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1] registers_chunk_data – Type: uint16_t[27], Range: [0 to 2¹⁶ - 1] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to write multiple holding registers. The parameters are request ID of the request, the number of the first holding register and the data to be written as received by the request. The number of the first holding register is called starting address for backwards compatibility reasons. It is not an address, but instead a holding register number in the range of 1 to 65536. The prefix digit 4 (for holding register) is omitted.

To send a response of this request use tf_rs485_modbus_slave_answer_write_multiple_registers_request().

int tf_rs485_register_modbus_master_write_multiple_registers_response_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterWriteMultipleRegistersResponseHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to write multiple registers.

The parameters are request ID of the request and exception code of the response.

Any non-zero exception code indicates a problem. If the exception code is greater than 0 then the number represents a Modbus exception code. If it is less than 0 then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by tf_rs485_set_modbus_configuration().

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_read_discrete_inputs_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveReadDiscreteInputsRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 2000] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read discrete inputs. The parameters are request ID of the request, the number of the first discrete input and the number of discrete inputs to be read as received by the request. The number of the first discrete input is called starting address for backwards compatibility reasons. It is not an address, but instead a discrete input number in the range of 1 to 65536. The prefix digit 1 (for discrete input) is omitted.

To send a response of this request use tf_rs485_modbus_slave_answer_read_discrete_inputs_request().

int tf_rs485_register_modbus_master_read_discrete_inputs_response_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterReadDiscreteInputsResponseLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, uint16_t discrete_inputs_length, uint16_t discrete_inputs_chunk_offset, bool discrete_inputs_chunk_data[464], void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] exception_code – Type: int8_t, Range: See constants discrete_inputs_length – Type: uint16_t, Range: [1 to 2000] discrete_inputs_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1] discrete_inputs_chunk_data – Type: bool[464] user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to read discrete inputs.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than 0 then the number represents a Modbus exception code. If it is less than 0 then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by tf_rs485_set_modbus_configuration().

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_modbus_slave_read_input_registers_request_callback(TF_RS485 *rs485, TF_RS485_ModbusSlaveReadInputRegistersRequestHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, uint32_t starting_address, uint16_t count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * request_id – Type: uint8_t, Range: [0 to 255] starting_address – Type: uint32_t, Range: [1 to 2¹⁶] count – Type: uint16_t, Range: [1 to 125] user_data – Type: void *

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read input registers. The parameters are request ID of the request, the number of the first input register and the number of input registers to be read as received by the request. The number of the first input register is called starting address for backwards compatibility reasons. It is not an address, but instead a input register number in the range of 1 to 65536. The prefix digit 3 (for input register) is omitted.

To send a response of this request use tf_rs485_modbus_slave_answer_read_input_registers_request().

int tf_rs485_register_modbus_master_read_input_registers_response_low_level_callback(TF_RS485 *rs485, TF_RS485_ModbusMasterReadInputRegistersResponseLowLevelHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint8_t request_id, int8_t exception_code, uint16_t input_registers_length, uint16_t input_registers_chunk_offset, uint16_t input_registers_chunk_data[29], void *user_data)

Callback Parameters:

rs485 – Type: TF_RS485 *
request_id – Type: uint8_t, Range: [0 to 255]
exception_code – Type: int8_t, Range: See constants
input_registers_length – Type: uint16_t, Range: [1 to 125]
input_registers_chunk_offset – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
input_registers_chunk_data – Type: uint16_t[29], Range: [0 to 2¹⁶ - 1]
user_data – Type: void *

This callback is called only in Modbus master mode when the master receives a valid response of a request to read input registers.

The parameters are request ID of the request, exception code of the response and the data as received by the response.

Any non-zero exception code indicates a problem. If the exception code is greater than 0 then the number represents a Modbus exception code. If it is less than 0 then it represents other errors. For example, -1 indicates that the request timedout or that the master did not receive any valid response of the request within the master request timeout period as set by tf_rs485_set_modbus_configuration().

The following constants are available for this function:

For exception_code:

TF_RS485_EXCEPTION_CODE_TIMEOUT = -1
TF_RS485_EXCEPTION_CODE_SUCCESS = 0
TF_RS485_EXCEPTION_CODE_ILLEGAL_FUNCTION = 1
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_ADDRESS = 2
TF_RS485_EXCEPTION_CODE_ILLEGAL_DATA_VALUE = 3
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_FAILURE = 4
TF_RS485_EXCEPTION_CODE_ACKNOWLEDGE = 5
TF_RS485_EXCEPTION_CODE_SLAVE_DEVICE_BUSY = 6
TF_RS485_EXCEPTION_CODE_MEMORY_PARITY_ERROR = 8
TF_RS485_EXCEPTION_CODE_GATEWAY_PATH_UNAVAILABLE = 10
TF_RS485_EXCEPTION_CODE_GATEWAY_TARGET_DEVICE_FAILED_TO_RESPOND = 11

int tf_rs485_register_frame_readable_callback(TF_RS485 *rs485, TF_RS485_FrameReadableHandler handler, void *user_data)¶

void handler(TF_RS485 *rs485, uint16_t frame_count, void *user_data)

Callback Parameters:	rs485 – Type: TF_RS485 * frame_count – Type: uint16_t, Range: [0 to 2¹⁶ - 1] user_data – Type: void *

This callback is called if at least one frame of data is readable. The frame size is configured with tf_rs485_set_frame_readable_callback_configuration(). The frame count parameter is the number of frames that can be read. This callback is triggered only once until tf_rs485_read() is called. This means, that if you have configured a frame size of X bytes, you can read exactly X bytes using the tf_rs485_read() function, every time the callback triggers without checking the frame count parameter.

New in version 2.0.5 (Plugin).

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object.

int tf_rs485_get_response_expected(TF_RS485 *rs485, uint8_t function_id, bool *ret_response_expected)¶

Parameters:	rs485 – Type: TF_RS485 * function_id – Type: uint8_t, Range: See constants
Output Parameters:	ret_response_expected – Type: bool
Returns:	e_code – Type: int

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by tf_rs485_set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

TF_RS485_FUNCTION_ENABLE_READ_CALLBACK = 3
TF_RS485_FUNCTION_DISABLE_READ_CALLBACK = 4
TF_RS485_FUNCTION_SET_RS485_CONFIGURATION = 6
TF_RS485_FUNCTION_SET_MODBUS_CONFIGURATION = 8
TF_RS485_FUNCTION_SET_MODE = 10
TF_RS485_FUNCTION_SET_COMMUNICATION_LED_CONFIG = 12
TF_RS485_FUNCTION_SET_ERROR_LED_CONFIG = 14
TF_RS485_FUNCTION_SET_BUFFER_CONFIG = 16
TF_RS485_FUNCTION_ENABLE_ERROR_COUNT_CALLBACK = 19
TF_RS485_FUNCTION_DISABLE_ERROR_COUNT_CALLBACK = 20
TF_RS485_FUNCTION_MODBUS_SLAVE_REPORT_EXCEPTION = 24
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_COILS_REQUEST = 25
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_HOLDING_REGISTERS_REQUEST = 27
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_SINGLE_COIL_REQUEST = 29
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_SINGLE_REGISTER_REQUEST = 31
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_MULTIPLE_COILS_REQUEST = 33
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_MULTIPLE_REGISTERS_REQUEST = 35
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_DISCRETE_INPUTS_REQUEST = 37
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_INPUT_REGISTERS_REQUEST = 39
TF_RS485_FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 59
TF_RS485_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_RS485_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_RS485_FUNCTION_RESET = 243
TF_RS485_FUNCTION_WRITE_UID = 248

int tf_rs485_set_response_expected(TF_RS485 *rs485, uint8_t function_id, bool response_expected)¶

Parameters:	rs485 – Type: TF_RS485 * function_id – Type: uint8_t, Range: See constants response_expected – Type: bool
Returns:	e_code – Type: int

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

The following constants are available for this function:

For function_id:

TF_RS485_FUNCTION_ENABLE_READ_CALLBACK = 3
TF_RS485_FUNCTION_DISABLE_READ_CALLBACK = 4
TF_RS485_FUNCTION_SET_RS485_CONFIGURATION = 6
TF_RS485_FUNCTION_SET_MODBUS_CONFIGURATION = 8
TF_RS485_FUNCTION_SET_MODE = 10
TF_RS485_FUNCTION_SET_COMMUNICATION_LED_CONFIG = 12
TF_RS485_FUNCTION_SET_ERROR_LED_CONFIG = 14
TF_RS485_FUNCTION_SET_BUFFER_CONFIG = 16
TF_RS485_FUNCTION_ENABLE_ERROR_COUNT_CALLBACK = 19
TF_RS485_FUNCTION_DISABLE_ERROR_COUNT_CALLBACK = 20
TF_RS485_FUNCTION_MODBUS_SLAVE_REPORT_EXCEPTION = 24
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_COILS_REQUEST = 25
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_HOLDING_REGISTERS_REQUEST = 27
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_SINGLE_COIL_REQUEST = 29
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_SINGLE_REGISTER_REQUEST = 31
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_MULTIPLE_COILS_REQUEST = 33
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_WRITE_MULTIPLE_REGISTERS_REQUEST = 35
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_DISCRETE_INPUTS_REQUEST = 37
TF_RS485_FUNCTION_MODBUS_SLAVE_ANSWER_READ_INPUT_REGISTERS_REQUEST = 39
TF_RS485_FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 59
TF_RS485_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
TF_RS485_FUNCTION_SET_STATUS_LED_CONFIG = 239
TF_RS485_FUNCTION_RESET = 243
TF_RS485_FUNCTION_WRITE_UID = 248

int tf_rs485_set_response_expected_all(TF_RS485 *rs485, bool response_expected)¶

Parameters:	rs485 – Type: TF_RS485 * response_expected – Type: bool
Returns:	e_code – Type: int

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Internal Functions¶

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

int tf_rs485_set_bootloader_mode(TF_RS485 *rs485, uint8_t mode, uint8_t *ret_status)¶

Parameters:	rs485 – Type: TF_RS485 * mode – Type: uint8_t, Range: See constants
Output Parameters:	ret_status – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

For mode:

TF_RS485_BOOTLOADER_MODE_BOOTLOADER = 0
TF_RS485_BOOTLOADER_MODE_FIRMWARE = 1
TF_RS485_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_RS485_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_RS485_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For ret_status:

TF_RS485_BOOTLOADER_STATUS_OK = 0
TF_RS485_BOOTLOADER_STATUS_INVALID_MODE = 1
TF_RS485_BOOTLOADER_STATUS_NO_CHANGE = 2
TF_RS485_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
TF_RS485_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
TF_RS485_BOOTLOADER_STATUS_CRC_MISMATCH = 5

int tf_rs485_get_bootloader_mode(TF_RS485 *rs485, uint8_t *ret_mode)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_mode – Type: uint8_t, Range: See constants
Returns:	e_code – Type: int

Returns the current bootloader mode, see tf_rs485_set_bootloader_mode().

The following constants are available for this function:

For ret_mode:

TF_RS485_BOOTLOADER_MODE_BOOTLOADER = 0
TF_RS485_BOOTLOADER_MODE_FIRMWARE = 1
TF_RS485_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
TF_RS485_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
TF_RS485_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

int tf_rs485_set_write_firmware_pointer(TF_RS485 *rs485, uint32_t pointer)¶

Parameters:	rs485 – Type: TF_RS485 * pointer – Type: uint32_t, Unit: 1 B, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Sets the firmware pointer for tf_rs485_write_firmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int tf_rs485_write_firmware(TF_RS485 *rs485, const uint8_t data[64], uint8_t *ret_status)¶

Parameters:	rs485 – Type: TF_RS485 * data – Type: const uint8_t[64], Range: [0 to 255]
Output Parameters:	ret_status – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

Writes 64 Bytes of firmware at the position as written by tf_rs485_set_write_firmware_pointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int tf_rs485_write_uid(TF_RS485 *rs485, uint32_t uid)¶

Parameters:	rs485 – Type: TF_RS485 * uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

int tf_rs485_read_uid(TF_RS485 *rs485, uint32_t *ret_uid)¶

Parameters:	rs485 – Type: TF_RS485 *
Output Parameters:	ret_uid – Type: uint32_t, Range: [0 to 2³² - 1]
Returns:	e_code – Type: int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

Constants¶

TF_RS485_DEVICE_IDENTIFIER¶

This constant is used to identify a RS485 Bricklet.

The functions tf_rs485_get_identity() and tf_hal_get_device_info() have a device_identifier output parameter to specify the Brick's or Bricklet's type.

TF_RS485_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a RS485 Bricklet.