Specifications / Modbus Protocol / API / Bricklets / Isolator Bricklet

Modbus - Isolator Bricklet¶

This is the description of the Modbus protocol for the Isolator Bricklet. General information and technical specifications for the Isolator Bricklet are summarized in its hardware description.

API¶

A general description of the Modbus protocol structure can be found here.

Basic Functions¶

BrickletIsolator.get_statistics¶

Function ID:	1
Request:	empty payload
Response:	messages_from_brick – Type: uint32, Range: [0 to 2³² - 1] messages_from_bricklet – Type: uint32, Range: [0 to 2³² - 1] connected_bricklet_device_identifier – Type: uint16, Range: [0 to 2¹⁶ - 1] connected_bricklet_uid – Type: char[8]

Returns statistics for the Isolator Bricklet.

Advanced Functions¶

BrickletIsolator.set_spitfp_baudrate_config¶

Function ID:	2
Request:	enable_dynamic_baudrate – Type: bool, Default: true minimum_dynamic_baudrate – Type: uint32, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000
Response:	no response

The SPITF protocol can be used with a dynamic baudrate. If the dynamic baudrate is enabled, the Isolator Bricklet will try to adapt the baudrate for the communication between Bricks and Bricklets according to the amount of data that is transferred.

The baudrate for communication config between Brick and Isolator Bricklet can be set through the API of the Brick.

The baudrate will be increased exponentially if lots of data is sent/received and decreased linearly if little data is sent/received.

This lowers the baudrate in applications where little data is transferred (e.g. a weather station) and increases the robustness. If there is lots of data to transfer (e.g. Thermal Imaging Bricklet) it automatically increases the baudrate as needed.

In cases where some data has to transferred as fast as possible every few seconds (e.g. RS485 Bricklet with a high baudrate but small payload) you may want to turn the dynamic baudrate off to get the highest possible performance.

The maximum value of the baudrate can be set per port with the function set_spitfp_baudrate. If the dynamic baudrate is disabled, the baudrate as set by set_spitfp_baudrate will be used statically.

BrickletIsolator.get_spitfp_baudrate_config¶

Function ID:	3
Request:	empty payload
Response:	enable_dynamic_baudrate – Type: bool, Default: true minimum_dynamic_baudrate – Type: uint32, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000

Returns the baudrate config, see set_spitfp_baudrate_config.

BrickletIsolator.set_spitfp_baudrate¶

Function ID:	4
Request:	baudrate – Type: uint32, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000
Response:	no response

Sets the baudrate for a the communication between Isolator Bricklet and the connected Bricklet. The baudrate for communication between Brick and Isolator Bricklet can be set through the API of the Brick.

If you want to increase the throughput of Bricklets you can increase the baudrate. If you get a high error count because of high interference (see get_spitfp_error_count) you can decrease the baudrate.

If the dynamic baudrate feature is enabled, the baudrate set by this function corresponds to the maximum baudrate (see set_spitfp_baudrate_config).

Regulatory testing is done with the default baudrate. If CE compatibility or similar is necessary in your applications we recommend to not change the baudrate.

BrickletIsolator.get_spitfp_baudrate¶

Function ID:	5
Request:	empty payload
Response:	baudrate – Type: uint32, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000

Returns the baudrate, see set_spitfp_baudrate.

BrickletIsolator.get_isolator_spitfp_error_count¶

Function ID:	6
Request:	empty payload
Response:	error_count_ack_checksum – Type: uint32, Range: [0 to 2³² - 1] error_count_message_checksum – Type: uint32, Range: [0 to 2³² - 1] error_count_frame – Type: uint32, Range: [0 to 2³² - 1] error_count_overflow – Type: uint32, Range: [0 to 2³² - 1]

Returns the error count for the communication between Isolator Bricklet and the connected Bricklet. Call get_spitfp_error_count to get the error count between Isolator Bricklet and Brick.

The errors are divided into

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

BrickletIsolator.get_spitfp_error_count¶

Function ID:	234
Request:	empty payload
Response:	error_count_ack_checksum – Type: uint32, Range: [0 to 2³² - 1] error_count_message_checksum – Type: uint32, Range: [0 to 2³² - 1] error_count_frame – Type: uint32, Range: [0 to 2³² - 1] error_count_overflow – Type: uint32, 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.

BrickletIsolator.set_status_led_config¶

Function ID:	239
Request:	config – Type: uint8, Range: See meanings, 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 meanings are defined for the elements of this function:

For config:

0 = Off
1 = On
2 = Show Heartbeat
3 = Show Status

BrickletIsolator.get_status_led_config¶

Function ID:	240
Request:	empty payload
Response:	config – Type: uint8, Range: See meanings, Default: 3

Returns the configuration as set by set_status_led_config

The following meanings are defined for the elements of this function:

For config:

0 = Off
1 = On
2 = Show Heartbeat
3 = Show Status

BrickletIsolator.get_chip_temperature¶

Function ID:	242
Request:	empty payload
Response:	temperature – Type: int16, 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.

BrickletIsolator.reset¶

Function ID:	243
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!

BrickletIsolator.get_identity¶

Function ID:	255
Request:	empty payload
Response:	uid – Type: char[8] connected_uid – Type: char[8] position – Type: char, Range: ['a' to 'h', 'z'] hardware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] firmware_version – Type: uint8[3] 0: major – Type: uint8, Range: [0 to 255] 1: minor – Type: uint8, Range: [0 to 255] 2: revision – Type: uint8, Range: [0 to 255] device_identifier – Type: uint16, Range: [0 to 2¹⁶ - 1]

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.

Callback Configuration Functions¶

BrickletIsolator.set_statistics_callback_configuration¶

Function ID:	7
Request:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 value_has_to_change – Type: bool, Default: false
Response:	no response

The period is the period with which the CALLBACK_STATISTICS callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

New in version 2.0.2 (Plugin).

BrickletIsolator.get_statistics_callback_configuration¶

Function ID:	8
Request:	empty payload
Response:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0 value_has_to_change – Type: bool, Default: false

Returns the callback configuration as set by set_statistics_callback_configuration.

New in version 2.0.2 (Plugin).

Callbacks¶

BrickletIsolator.CALLBACK_STATISTICS¶

Function ID:	9
Response:	messages_from_brick – Type: uint32, Range: [0 to 2³² - 1] messages_from_bricklet – Type: uint32, Range: [0 to 2³² - 1] connected_bricklet_device_identifier – Type: uint16, Range: [0 to 2¹⁶ - 1] connected_bricklet_uid – Type: char[8]

This callback is triggered periodically according to the configuration set by set_statistics_callback_configuration.

The response values are the same as get_statistics.

New in version 2.0.2 (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.

BrickletIsolator.set_bootloader_mode¶

Function ID:	235
Request:	mode – Type: uint8, Range: See meanings
Response:	status – Type: uint8, Range: See meanings

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 meanings are defined for the elements of this function:

For mode:

0 = Bootloader
1 = Firmware
2 = Bootloader Wait For Reboot
3 = Firmware Wait For Reboot
4 = Firmware Wait For Erase And Reboot

For status:

0 = OK
1 = Invalid Mode
2 = No Change
3 = Entry Function Not Present
4 = Device Identifier Incorrect
5 = CRC Mismatch

BrickletIsolator.get_bootloader_mode¶

Function ID:	236
Request:	empty payload
Response:	mode – Type: uint8, Range: See meanings

Returns the current bootloader mode, see set_bootloader_mode.

The following meanings are defined for the elements of this function:

For mode:

0 = Bootloader
1 = Firmware
2 = Bootloader Wait For Reboot
3 = Firmware Wait For Reboot
4 = Firmware Wait For Erase And Reboot

BrickletIsolator.set_write_firmware_pointer¶

Function ID:	237
Request:	pointer – Type: uint32, Unit: 1 B, Range: [0 to 2³² - 1]
Response:	no response

Sets the firmware pointer for 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.

BrickletIsolator.write_firmware¶

Function ID:	238
Request:	data – Type: uint8[64], Range: [0 to 255]
Response:	status – Type: uint8, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by 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.

BrickletIsolator.write_uid¶

Function ID:	248
Request:	uid – Type: uint32, 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.

BrickletIsolator.read_uid¶

Function ID:	249
Request:	empty payload
Response:	uid – Type: uint32, Range: [0 to 2³² - 1]

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