MQTT - RS485 Bricklet¶

Loopback¶

Download (example-loopback.txt)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18

# 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

# Change XYZ to the UID of your RS485 Bricklet

setup:
    # Enable full-duplex mode
    publish '{"baudrate": 115200, "parity": "none", "stopbits": "1", "wordlength": "8", "duplex": "full"}' to tinkerforge/request/rs485_bricklet/XYZ/set_rs485_configuration

    # Handle incoming read callbacks
    subscribe to tinkerforge/callback/rs485_bricklet/XYZ/read # Received messages contain the message as string
    publish '{"register": true}' to tinkerforge/register/rs485_bricklet/XYZ/read # Register read callback

    # Enable read callback
    publish '' to tinkerforge/request/rs485_bricklet/XYZ/enable_read_callback

    # Send test message
    publish '{"message": "test"}' to tinkerforge/request/rs485_bricklet/XYZ/write

Modbus Master¶

Download (example-modbus-master.txt)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

# Change XYZ to the UID of your RS485 Bricklet

setup:
    # Set operating mode to Modbus RTU master
    publish '{"mode": "modbus_master_rtu"}' to tinkerforge/request/rs485_bricklet/XYZ/set_mode

    # Modbus specific configuration:
    # - slave address = 1 (unused in master mode)
    # - master request timeout = 1000ms
    publish '{"slave_address": 1, "master_request_timeout": 1000}' to tinkerforge/request/rs485_bricklet/XYZ/set_modbus_configuration

    # Handle incoming Modbus master write single register response callbacks
    subscribe to tinkerforge/callback/rs485_bricklet/XYZ/modbus_master_write_single_register_response
        if a message arrives
            # message contains request_id as int and exception_code as int with symbols
            print request_id
            if exception_code != "Timeout
                print exception_code
            endif
        endif
    endsubscribe

    publish '{"register": true}' to tinkerforge/register/rs485_bricklet/XYZ/modbus_master_write_single_register_response # Register modbus_master_write_single_register_response callback

    # Write 65535 to register 42 of slave 17
    publish '{"slave_address": 17, "register_address": 42, "register_value": 65535}' to tinkerforge/request/rs485_bricklet/XYZ/modbus_master_write_single_register

Modbus Slave¶

Download (example-modbus-slave.txt)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

# Change XYZ to the UID of your RS485 Bricklet

setup:
    # Set operating mode to Modbus RTU slave
    publish '{"mode": "modbus_slave_rtu"}' to tinkerforge/request/rs485_bricklet/XYZ/set_mode

    # Modbus specific configuration:
    # - slave address = 17
    # - master request timeout = 0ms (unused in slave mode)
    publish '{"slave_address": 17, "master_request_timeout": 0}' to tinkerforge/request/rs485_bricklet/XYZ/set_modbus_configuration

    # Handle incoming Modbus slave write single register request callbacks
    subscribe to tinkerforge/callback/rs485_bricklet/XYZ/modbus_slave_write_single_register_request
        if a message arrives
            # message contains request_id as int, register_address as ant and register_value as int

            if registerAddress != 42
                print "Error: Invalid register address"
                publish '{"request_id": request_id, "exception_code": "IllegalDataAddress"}' to tinkerforge/request/rs485_bricklet/XYZ/modbus_slave_report_exception
            elseif
                publish '{"request_id": request_id}' to tinkerforge/request/rs485_bricklet/XYZ/modbus_slave_answer_write_single_register_request
            endif
        endif
    endsubscribe

    publish '{"register": true}' to tinkerforge/register/rs485_bricklet/XYZ/modbus_slave_write_single_register_request # Register modbus_slave_write_single_register_request callback

Basic Functions¶

request/rs485_bricklet/<UID>/write¶

Request:	message – Type: [char, ...], Length: variable
Response:	message_written – Type: int, Range: [0 to 216 - 1]

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 request/rs485_bricklet/<UID>/set_rs485_configuration for configuration possibilities regarding baudrate, parity and so on.

request/rs485_bricklet/<UID>/read¶

Request:	length – Type: int, Range: [0 to 216 - 1]
Response:	message – Type: [char, ...], Length: variable

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 request/rs485_bricklet/<UID>/enable_read_callback and register/rs485_bricklet/<UID>/read callback.

request/rs485_bricklet/<UID>/set_rs485_configuration¶

Request:	baudrate – Type: int, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 parity – Type: int, Range: See symbols, Default: 0 stopbits – Type: int, Range: See symbols, Default: 1 wordlength – Type: int, Range: See symbols, Default: 8 duplex – Type: int, Range: See symbols, Default: 0
Response:	no response

Sets the configuration for the RS485 communication.

The following symbols are available for this function:

For parity:

• "none" = 0
• "odd" = 1
• "even" = 2

For stopbits:

• "1" = 1
• "2" = 2

For wordlength:

• "5" = 5
• "6" = 6
• "7" = 7
• "8" = 8

For duplex:

• "half" = 0
• "full" = 1

request/rs485_bricklet/<UID>/get_rs485_configuration¶

Request:	empty payload
Response:	baudrate – Type: int, Unit: 1 Bd, Range: [100 to 2000000], Default: 115200 parity – Type: int, Range: See symbols, Default: 0 stopbits – Type: int, Range: See symbols, Default: 1 wordlength – Type: int, Range: See symbols, Default: 8 duplex – Type: int, Range: See symbols, Default: 0

Returns the configuration as set by request/rs485_bricklet/<UID>/set_rs485_configuration.

The following symbols are available for this function:

For parity:

• "none" = 0
• "odd" = 1
• "even" = 2

For stopbits:

• "1" = 1
• "2" = 2

For wordlength:

• "5" = 5
• "6" = 6
• "7" = 7
• "8" = 8

For duplex:

• "half" = 0
• "full" = 1

request/rs485_bricklet/<UID>/set_modbus_configuration¶

Request:	slave_address – Type: int, Range: [1 to 247], Default: 1 master_request_timeout – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 1000
Response:	no response

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.

request/rs485_bricklet/<UID>/get_modbus_configuration¶

Request:	empty payload
Response:	slave_address – Type: int, Range: [1 to 247], Default: 1 master_request_timeout – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 1000

Returns the configuration as set by request/rs485_bricklet/<UID>/set_modbus_configuration.

request/rs485_bricklet/<UID>/set_mode¶

Request:	mode – Type: int, Range: See symbols, Default: 0
Response:	no response

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

• RS485,
• Modbus Master RTU and
• Modbus Slave RTU.

The following symbols are available for this function:

For mode:

• "rs485" = 0
• "modbus_master_rtu" = 1
• "modbus_slave_rtu" = 2

request/rs485_bricklet/<UID>/get_mode¶

Request:	empty payload
Response:	mode – Type: int, Range: See symbols, Default: 0

Returns the configuration as set by request/rs485_bricklet/<UID>/set_mode.

The following symbols are available for this function:

For mode:

• "rs485" = 0
• "modbus_master_rtu" = 1
• "modbus_slave_rtu" = 2

Advanced Functions¶

request/rs485_bricklet/<UID>/set_communication_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

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 symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_communication" = 3

request/rs485_bricklet/<UID>/get_communication_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/rs485_bricklet/<UID>/set_communication_led_config

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_communication" = 3

request/rs485_bricklet/<UID>/set_error_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

Sets the error LED configuration.

By default the error LED turns on if there is any error (see register/rs485_bricklet/<UID>/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 symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_error" = 3

request/rs485_bricklet/<UID>/get_error_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/rs485_bricklet/<UID>/set_error_led_config.

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_error" = 3

request/rs485_bricklet/<UID>/set_buffer_config¶

Request:	send_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120 receive_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120
Response:	no response

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 request/rs485_bricklet/<UID>/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 request/rs485_bricklet/<UID>/read or through register/rs485_bricklet/<UID>/read callback.

request/rs485_bricklet/<UID>/get_buffer_config¶

Request:	empty payload
Response:	send_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120 receive_buffer_size – Type: int, Unit: 1 B, Range: [210 to 9216], Default: 5120

Returns the buffer configuration as set by request/rs485_bricklet/<UID>/set_buffer_config.

request/rs485_bricklet/<UID>/get_buffer_status¶

Request:	empty payload
Response:	send_buffer_used – Type: int, Unit: 1 B, Range: [0 to 9216] receive_buffer_used – Type: int, Unit: 1 B, Range: [0 to 9216]

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

See request/rs485_bricklet/<UID>/set_buffer_config for buffer size configuration.

request/rs485_bricklet/<UID>/get_error_count¶

Request:	empty payload
Response:	overrun_error_count – Type: int, Range: [0 to 232 - 1] parity_error_count – Type: int, Range: [0 to 232 - 1]

Returns the current number of overrun and parity errors.

request/rs485_bricklet/<UID>/get_modbus_common_error_count¶

Request:

empty payload

Response:

timeout_error_count – Type: int, Range: [0 to 232 - 1] checksum_error_count – Type: int, Range: [0 to 232 - 1] frame_too_big_error_count – Type: int, Range: [0 to 232 - 1] illegal_function_error_count – Type: int, Range: [0 to 232 - 1] illegal_data_address_error_count – Type: int, Range: [0 to 232 - 1] illegal_data_value_error_count – Type: int, Range: [0 to 232 - 1] slave_device_failure_error_count – Type: int, Range: [0 to 232 - 1]

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.

request/rs485_bricklet/<UID>/modbus_slave_report_exception¶

Request:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols
Response:	no response

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 symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

request/rs485_bricklet/<UID>/modbus_slave_answer_read_coils_request¶

Request:	request_id – Type: int, Range: [0 to 255] coils – Type: [bool, ...], Length: variable
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_read_coils_request callback with the Request ID as provided by the argument of the callback.

request/rs485_bricklet/<UID>/modbus_master_read_coils¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 2000]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/modbus_master_read_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.

request/rs485_bricklet/<UID>/modbus_slave_answer_read_holding_registers_request¶

Request:	request_id – Type: int, Range: [0 to 255] holding_registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_read_holding_registers_request callback with the Request ID as provided by the argument of the callback.

request/rs485_bricklet/<UID>/modbus_master_read_holding_registers¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 125]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/modbus_master_read_holding_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.

request/rs485_bricklet/<UID>/modbus_slave_answer_write_single_coil_request¶

Request:	request_id – Type: int, Range: [0 to 255]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_write_single_coil_request callback with the Request ID as provided by the arguments of the callback.

request/rs485_bricklet/<UID>/modbus_master_write_single_coil¶

Request:	slave_address – Type: int, Range: [0 to 247] coil_address – Type: int, Range: [1 to 216] coil_value – Type: bool
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/modbus_slave_answer_write_single_register_request¶

Request:	request_id – Type: int, Range: [0 to 255]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_write_single_register_request callback with the Request ID, Register Address and Register Value as provided by the arguments of the callback.

request/rs485_bricklet/<UID>/modbus_master_write_single_register¶

Request:	slave_address – Type: int, Range: [0 to 247] register_address – Type: int, Range: [1 to 216] register_value – Type: int, Range: [0 to 216 - 1]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/modbus_slave_answer_write_multiple_coils_request¶

Request:	request_id – Type: int, Range: [0 to 255]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_write_multiple_coils_request callback with the Request ID of the callback.

request/rs485_bricklet/<UID>/modbus_master_write_multiple_coils¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] coils – Type: [bool, ...], Length: variable
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/modbus_slave_answer_write_multiple_registers_request¶

Request:	request_id – Type: int, Range: [0 to 255]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_write_multiple_registers_request callback with the Request ID of the callback.

request/rs485_bricklet/<UID>/modbus_master_write_multiple_registers¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/modbus_slave_answer_read_discrete_inputs_request¶

Request:	request_id – Type: int, Range: [0 to 255] discrete_inputs – Type: [bool, ...], Length: variable
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_read_discrete_inputs_request callback with the Request ID as provided by the argument of the callback.

request/rs485_bricklet/<UID>/modbus_master_read_discrete_inputs¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 2000]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/modbus_master_read_discrete_inputs_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.

request/rs485_bricklet/<UID>/modbus_slave_answer_read_input_registers_request¶

Request:	request_id – Type: int, Range: [0 to 255] input_registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]
Response:	no response

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 register/rs485_bricklet/<UID>/modbus_slave_read_input_registers_request callback with the Request ID as provided by the argument of the callback.

request/rs485_bricklet/<UID>/modbus_master_read_input_registers¶

Request:	slave_address – Type: int, Range: [0 to 247] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 125]
Response:	request_id – Type: int, Range: [0 to 255]

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 register/rs485_bricklet/<UID>/modbus_master_read_input_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.

request/rs485_bricklet/<UID>/get_spitfp_error_count¶

Request:	empty payload
Response:	error_count_ack_checksum – Type: int, Range: [0 to 232 - 1] error_count_message_checksum – Type: int, Range: [0 to 232 - 1] error_count_frame – Type: int, Range: [0 to 232 - 1] error_count_overflow – Type: int, Range: [0 to 232 - 1]

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.

request/rs485_bricklet/<UID>/set_status_led_config¶

Request:	config – Type: int, Range: See symbols, Default: 3
Response:	no response

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 symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_status" = 3

request/rs485_bricklet/<UID>/get_status_led_config¶

Request:	empty payload
Response:	config – Type: int, Range: See symbols, Default: 3

Returns the configuration as set by request/rs485_bricklet/<UID>/set_status_led_config

The following symbols are available for this function:

For config:

• "off" = 0
• "on" = 1
• "show_heartbeat" = 2
• "show_status" = 3

request/rs485_bricklet/<UID>/get_chip_temperature¶

Request:	empty payload
Response:	temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

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.

request/rs485_bricklet/<UID>/reset¶

Request:	empty payload
Response:	no response

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!

request/rs485_bricklet/<UID>/get_identity¶

Request:

empty payload

Response:

uid – Type: string, Length: up to 8 connected_uid – Type: string, Length: up to 8 position – Type: char, Range: ["a" to "h", "z"] hardware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] firmware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] device_identifier – Type: int, Range: [0 to 216 - 1] _display_name – Type: string

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. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the RS485's name in a human readable form.

Callback Configuration Functions¶

request/rs485_bricklet/<UID>/enable_read_callback¶

Request:	empty payload
Response:	no response

Enables the register/rs485_bricklet/<UID>/read callback. This will disable the register/rs485_bricklet/<UID>/frame_readable callback.

By default the callback is disabled.

request/rs485_bricklet/<UID>/disable_read_callback¶

Request:	empty payload
Response:	no response

Disables the register/rs485_bricklet/<UID>/read callback.

By default the callback is disabled.

request/rs485_bricklet/<UID>/is_read_callback_enabled¶

Request:	empty payload
Response:	enabled – Type: bool, Default: false

Returns true if the register/rs485_bricklet/<UID>/read callback is enabled, false otherwise.

request/rs485_bricklet/<UID>/enable_error_count_callback¶

Request:	empty payload
Response:	no response

Enables the register/rs485_bricklet/<UID>/error_count callback.

By default the callback is disabled.

request/rs485_bricklet/<UID>/disable_error_count_callback¶

Request:	empty payload
Response:	no response

Disables the register/rs485_bricklet/<UID>/error_count callback.

By default the callback is disabled.

request/rs485_bricklet/<UID>/is_error_count_callback_enabled¶

Request:	empty payload
Response:	enabled – Type: bool, Default: true

Returns true if the register/rs485_bricklet/<UID>/error_count callback is enabled, false otherwise.

request/rs485_bricklet/<UID>/set_frame_readable_callback_configuration¶

Request:	frame_size – Type: int, Unit: 1 B, Range: [0 to 9216], Default: 0
Response:	no response

Configures the register/rs485_bricklet/<UID>/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 register/rs485_bricklet/<UID>/read callback.

By default the callback is disabled.

New in version 2.0.5 (Plugin).

request/rs485_bricklet/<UID>/get_frame_readable_callback_configuration¶

Request:	empty payload
Response:	frame_size – Type: int, Unit: 1 B, Range: [0 to 9216], Default: 0

Returns the callback configuration as set by request/rs485_bricklet/<UID>/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 .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

register/rs485_bricklet/<UID>/read¶

Register Request:	register – Type: bool
Callback Response:	message – Type: [char, ...], Length: variable

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/read[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/read[/<SUFFIX>] topic for each registered suffix.

This callback is called if new data is available.

To enable this callback, use request/rs485_bricklet/<UID>/enable_read_callback.

Note

If reconstructing the value fails, the callback is triggered with null for message.

register/rs485_bricklet/<UID>/error_count¶

Register Request:	register – Type: bool
Callback Response:	overrun_error_count – Type: int, Range: [0 to 232 - 1] parity_error_count – Type: int, Range: [0 to 232 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/error_count[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/error_count[/<SUFFIX>] topic for each registered suffix.

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

register/rs485_bricklet/<UID>/modbus_slave_read_coils_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 2000]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_read_coils_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_read_coils_request[/<SUFFIX>] topic for each registered suffix.

This callback is called only in Modbus slave mode when the slave receives a valid request from a Modbus master to read coils. The callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_read_coils_request.

register/rs485_bricklet/<UID>/modbus_master_read_coils_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols coils – Type: [bool, ...], Length: variable

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_read_coils_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_read_coils_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

Note

If reconstructing the value fails, the callback is triggered with null for coils.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_read_holding_registers_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 125]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_read_holding_registers_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_read_holding_registers_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_read_holding_registers_request.

register/rs485_bricklet/<UID>/modbus_master_read_holding_registers_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols holding_registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_read_holding_registers_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_read_holding_registers_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

Note

If reconstructing the value fails, the callback is triggered with null for holding_registers.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_write_single_coil_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] coil_address – Type: int, Range: [1 to 216] coil_value – Type: bool

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_write_single_coil_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_write_single_coil_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_write_single_coil_request.

register/rs485_bricklet/<UID>/modbus_master_write_single_coil_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_write_single_coil_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_write_single_coil_response[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 timed out or that the master did not receive any valid response of the request within the master request timeout period as set by request/rs485_bricklet/<UID>/set_modbus_configuration.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_write_single_register_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] register_address – Type: int, Range: [1 to 216] register_value – Type: int, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_write_single_register_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_write_single_register_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_write_single_register_request.

register/rs485_bricklet/<UID>/modbus_master_write_single_register_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_write_single_register_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_write_single_register_response[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 timed out or that the master did not receive any valid response of the request within the master request timeout period as set by request/rs485_bricklet/<UID>/set_modbus_configuration.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_write_multiple_coils_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] coils – Type: [bool, ...], Length: variable

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_write_multiple_coils_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_write_multiple_coils_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_write_multiple_coils_request.

Note

If reconstructing the value fails, the callback is triggered with null for coils.

register/rs485_bricklet/<UID>/modbus_master_write_multiple_coils_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_write_multiple_coils_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_write_multiple_coils_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_write_multiple_registers_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_write_multiple_registers_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_write_multiple_registers_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_write_multiple_registers_request.

Note

If reconstructing the value fails, the callback is triggered with null for registers.

register/rs485_bricklet/<UID>/modbus_master_write_multiple_registers_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_write_multiple_registers_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_write_multiple_registers_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_read_discrete_inputs_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 2000]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_read_discrete_inputs_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_read_discrete_inputs_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_read_discrete_inputs_request.

register/rs485_bricklet/<UID>/modbus_master_read_discrete_inputs_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols discrete_inputs – Type: [bool, ...], Length: variable

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_read_discrete_inputs_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_read_discrete_inputs_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

Note

If reconstructing the value fails, the callback is triggered with null for discrete_inputs.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/modbus_slave_read_input_registers_request¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] starting_address – Type: int, Range: [1 to 216] count – Type: int, Range: [1 to 125]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_slave_read_input_registers_request[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_slave_read_input_registers_request[/<SUFFIX>] topic for each registered suffix.

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 callback payload members 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 request/rs485_bricklet/<UID>/modbus_slave_answer_read_input_registers_request.

register/rs485_bricklet/<UID>/modbus_master_read_input_registers_response¶

Register Request:	register – Type: bool
Callback Response:	request_id – Type: int, Range: [0 to 255] exception_code – Type: int, Range: See symbols input_registers – Type: [int, ...], Length: variable, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/modbus_master_read_input_registers_response[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/modbus_master_read_input_registers_response[/<SUFFIX>] topic for each registered suffix.

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

The callback payload members 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 request/rs485_bricklet/<UID>/set_modbus_configuration.

Note

If reconstructing the value fails, the callback is triggered with null for input_registers.

The following symbols are available for this function:

For exception_code:

• "timeout" = -1
• "success" = 0
• "illegal_function" = 1
• "illegal_data_address" = 2
• "illegal_data_value" = 3
• "slave_device_failure" = 4
• "acknowledge" = 5
• "slave_device_busy" = 6
• "memory_parity_error" = 8
• "gateway_path_unavailable" = 10
• "gateway_target_device_failed_to_respond" = 11

register/rs485_bricklet/<UID>/frame_readable¶

Register Request:	register – Type: bool
Callback Response:	frame_count – Type: int, Range: [0 to 216 - 1]

A callback can be registered for this event by publishing to the .../register/rs485_bricklet/<UID>/frame_readable[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/rs485_bricklet/<UID>/frame_readable[/<SUFFIX>] topic for each registered suffix.

This callback is called if at least one frame of data is readable. The frame size is configured with request/rs485_bricklet/<UID>/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 request/rs485_bricklet/<UID>/read is called. This means, that if you have configured a frame size of X bytes, you can read exactly X bytes using the request/rs485_bricklet/<UID>/read function, every time the callback triggers without checking the frame count callback payload.

New in version 2.0.5 (Plugin).

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.

request/rs485_bricklet/<UID>/set_bootloader_mode¶

Request:	mode – Type: int, Range: See symbols
Response:	status – Type: int, Range: See symbols

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 symbols are available for this function:

For mode:

• "bootloader" = 0
• "firmware" = 1
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

For status:

• "ok" = 0
• "invalid_mode" = 1
• "no_change" = 2
• "entry_function_not_present" = 3
• "device_identifier_incorrect" = 4
• "crc_mismatch" = 5

request/rs485_bricklet/<UID>/get_bootloader_mode¶

Request:	empty payload
Response:	mode – Type: int, Range: See symbols

Returns the current bootloader mode, see request/rs485_bricklet/<UID>/set_bootloader_mode.

The following symbols are available for this function:

For mode:

• "bootloader" = 0
• "firmware" = 1
• "bootloader_wait_for_reboot" = 2
• "firmware_wait_for_reboot" = 3
• "firmware_wait_for_erase_and_reboot" = 4

request/rs485_bricklet/<UID>/set_write_firmware_pointer¶

Request:	pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Response:	no response

Sets the firmware pointer for request/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/write_firmware¶

Request:	data – Type: [int, ...], Length: 64, Range: [0 to 255]
Response:	status – Type: int, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by request/rs485_bricklet/<UID>/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.

request/rs485_bricklet/<UID>/write_uid¶

Request:	uid – Type: int, Range: [0 to 232 - 1]
Response:	no response

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.

request/rs485_bricklet/<UID>/read_uid¶

Request:	empty payload
Response:	uid – Type: int, Range: [0 to 232 - 1]

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