Specifications / Modbus Protocol / API / Bricklets (Discontinued) / Current12 Bricklet

Modbus - Current12 Bricklet¶

This is the description of the Modbus protocol for the Current12 Bricklet. General information and technical specifications for the Current12 Bricklet are summarized in its hardware description.

API¶

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

Basic Functions¶

BrickletCurrent12.get_current¶

Function ID:	1
Request:	empty payload
Response:	current – Type: int16, Unit: 1 mA, Range: [-12500 to 12500]

Returns the current of the sensor.

If you want to get the current periodically, it is recommended to use the CALLBACK_CURRENT callback and set the period with set_current_callback_period.

Advanced Functions¶

BrickletCurrent12.calibrate¶

Function ID:	2
Request:	empty payload
Response:	no response

Calibrates the 0 value of the sensor. You have to call this function when there is no current present.

The zero point of the current sensor is depending on the exact properties of the analog-to-digital converter, the length of the Bricklet cable and the temperature. Thus, if you change the Brick or the environment in which the Bricklet is used, you might have to recalibrate.

The resulting calibration will be saved on the EEPROM of the Current Bricklet.

BrickletCurrent12.is_over_current¶

Function ID:	3
Request:	empty payload
Response:	over – Type: bool

Returns true if more than 12.5A were measured.

Note

To reset this value you have to power cycle the Bricklet.

BrickletCurrent12.get_analog_value¶

Function ID:	4
Request:	empty payload
Response:	value – Type: uint16, Range: [0 to 2¹² - 1]

Returns the value as read by a 12-bit analog-to-digital converter.

Note

The value returned by get_current is averaged over several samples to yield less noise, while get_analog_value gives back raw unfiltered analog values. The only reason to use get_analog_value is, if you need the full resolution of the analog-to-digital converter.

If you want the analog value periodically, it is recommended to use the CALLBACK_ANALOG_VALUE callback and set the period with set_analog_value_callback_period.

BrickletCurrent12.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¶

BrickletCurrent12.set_current_callback_period¶

Function ID:	5
Request:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Response:	no response

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

The CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

BrickletCurrent12.get_current_callback_period¶

Function ID:	6
Request:	empty payload
Response:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0

Returns the period as set by set_current_callback_period.

BrickletCurrent12.set_analog_value_callback_period¶

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

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

The CALLBACK_ANALOG_VALUE callback is only triggered if the analog value has changed since the last triggering.

BrickletCurrent12.get_analog_value_callback_period¶

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

Returns the period as set by set_analog_value_callback_period.

BrickletCurrent12.set_current_callback_threshold¶

Function ID:	9
Request:	option – Type: char, Range: See meanings, Default: 'x' min – Type: int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0
Response:	no response

Sets the thresholds for the CALLBACK_CURRENT_REACHED callback.

The following options are possible:

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

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

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletCurrent12.get_current_callback_threshold¶

Function ID:	10
Request:	empty payload
Response:	option – Type: char, Range: See meanings, Default: 'x' min – Type: int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: int16, Unit: 1 mA, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Returns the threshold as set by set_current_callback_threshold.

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

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletCurrent12.set_analog_value_callback_threshold¶

Function ID:	11
Request:	option – Type: char, Range: See meanings, Default: 'x' min – Type: uint16, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: uint16, Range: [0 to 2¹⁶ - 1], Default: 0
Response:	no response

Sets the thresholds for the CALLBACK_ANALOG_VALUE_REACHED callback.

The following options are possible:

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

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

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletCurrent12.get_analog_value_callback_threshold¶

Function ID:	12
Request:	empty payload
Response:	option – Type: char, Range: See meanings, Default: 'x' min – Type: uint16, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: uint16, Range: [0 to 2¹⁶ - 1], Default: 0

Returns the threshold as set by set_analog_value_callback_threshold.

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

For option:

'x' = Off
'o' = Outside
'i' = Inside
'<' = Smaller
'>' = Greater

BrickletCurrent12.set_debounce_period¶

Function ID:	13
Request:	debounce – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100
Response:	no response

Sets the period with which the threshold callbacks

CALLBACK_CURRENT_REACHED,
CALLBACK_ANALOG_VALUE_REACHED

are triggered, if the thresholds

set_current_callback_threshold,
set_analog_value_callback_threshold

keep being reached.

BrickletCurrent12.get_debounce_period¶

Function ID:	14
Request:	empty payload
Response:	debounce – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100

Returns the debounce period as set by set_debounce_period.

Callbacks¶

BrickletCurrent12.CALLBACK_CURRENT¶

Function ID:	15
Response:	current – Type: int16, Unit: 1 mA, Range: [-12500 to 12500]

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

The CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

BrickletCurrent12.CALLBACK_ANALOG_VALUE¶

Function ID:	16
Response:	value – Type: uint16, Range: [0 to 2¹² - 1]

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

The CALLBACK_ANALOG_VALUE callback is only triggered if the current has changed since the last triggering.

BrickletCurrent12.CALLBACK_CURRENT_REACHED¶

Function ID:	17
Response:	current – Type: int16, Unit: 1 mA, Range: [-12500 to 12500]

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

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

BrickletCurrent12.CALLBACK_ANALOG_VALUE_REACHED¶

Function ID:	18
Response:	value – Type: uint16, Range: [0 to 2¹² - 1]

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

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

BrickletCurrent12.CALLBACK_OVER_CURRENT¶

Function ID:	19
Response:	empty payload

This callback is triggered when an over current is measured (see is_over_current).