Modbus - Temperature Bricklet

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

API

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

Basic Functions

BrickletTemperature.get_temperature
Function ID:

1

Request:

empty payload

Response:
  • temperature -- int16

Returns the temperature of the sensor. The value has a range of -2500 to 8500 and is given in °C/100, e.g. a value of 4223 means that a temperature of 42.23 °C is measured.

If you want to get the temperature periodically, it is recommended to use the CALLBACK_TEMPERATURE callback and set the period with set_temperature_callback_period.

Advanced Functions

BrickletTemperature.set_i2c_mode
Function ID:

10

Request:
  • mode -- uint8
Response:

no response

Sets the I2C mode. Possible modes are:

  • 0: Fast (400kHz, default)
  • 1: Slow (100kHz)

If you have problems with obvious outliers in the Temperature Bricklet measurements, they may be caused by EMI issues. In this case it may be helpful to lower the I2C speed.

It is however not recommended to lower the I2C speed in applications where a high throughput needs to be achieved.

New in version 2.0.1 (Plugin).

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

  • 0: fast, for mode
  • 1: slow, for mode
BrickletTemperature.get_i2c_mode
Function ID:

11

Request:

empty payload

Response:
  • mode -- uint8

Returns the I2C mode as set by set_i2c_mode.

New in version 2.0.1 (Plugin).

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

  • 0: fast, for mode
  • 1: slow, for mode
BrickletTemperature.get_identity
Function ID:

255

Request:

empty payload

Response:
  • uid -- char[8]
  • connected_uid -- char[8]
  • position -- char
  • hardware_version -- uint8[3]
  • firmware_version -- uint8[3]
  • device_identifier -- uint16

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' or 'd'.

The device identifier numbers can be found here

Callback Configuration Functions

BrickletTemperature.set_temperature_callback_period
Function ID:

2

Request:
  • period -- uint32
Response:

no response

Sets the period in ms with which the CALLBACK_TEMPERATURE callback is triggered periodically. A value of 0 turns the callback off.

The CALLBACK_TEMPERATURE callback is only triggered if the temperature has changed since the last triggering.

The default value is 0.

BrickletTemperature.get_temperature_callback_period
Function ID:

3

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_temperature_callback_period.

BrickletTemperature.set_temperature_callback_threshold
Function ID:

4

Request:
  • option -- char
  • min -- int16
  • max -- int16
Response:

no response

Sets the thresholds for the CALLBACK_TEMPERATURE_REACHED callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the temperature is outside the min and max values
'i' Callback is triggered when the temperature is inside the min and max values
'<' Callback is triggered when the temperature is smaller than the min value (max is ignored)
'>' Callback is triggered when the temperature is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

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

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletTemperature.get_temperature_callback_threshold
Function ID:

5

Request:

empty payload

Response:
  • option -- char
  • min -- int16
  • max -- int16

Returns the threshold as set by set_temperature_callback_threshold.

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

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletTemperature.set_debounce_period
Function ID:

6

Request:
  • debounce -- uint32
Response:

no response

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

BrickletTemperature.get_debounce_period
Function ID:

7

Request:

empty payload

Response:
  • debounce -- uint32

Returns the debounce period as set by set_debounce_period.

Callbacks

BrickletTemperature.CALLBACK_TEMPERATURE
Function ID:

8

Response:
  • temperature -- int16

This callback is triggered periodically with the period that is set by set_temperature_callback_period. The response value is the temperature of the sensor.

The CALLBACK_TEMPERATURE callback is only triggered if the temperature has changed since the last triggering.

BrickletTemperature.CALLBACK_TEMPERATURE_REACHED
Function ID:

9

Response:
  • temperature -- int16

This callback is triggered when the threshold as set by set_temperature_callback_threshold is reached. The response value is the temperature of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set_debounce_period.