Specifications / Modbus Protocol / API / Bricklets (Discontinued) / Rotary Encoder Bricklet

Modbus - Rotary Encoder Bricklet¶

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

API¶

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

Basic Functions¶

BrickletRotaryEncoder.get_count¶

Function ID:	1
Request:	reset – Type: bool
Response:	count – Type: int32, Range: [-2³¹ to 2³¹ - 1]

Returns the current count of the encoder. If you set reset to true, the count is set back to 0 directly after the current count is read.

The encoder has 24 steps per rotation

Turning the encoder to the left decrements the counter, so a negative count is possible.

BrickletRotaryEncoder.is_pressed¶

Function ID:	10
Request:	empty payload
Response:	pressed – Type: bool

Returns true if the button is pressed and false otherwise.

It is recommended to use the CALLBACK_PRESSED and CALLBACK_RELEASED callbacks to handle the button.

Advanced Functions¶

BrickletRotaryEncoder.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¶

BrickletRotaryEncoder.set_count_callback_period¶

Function ID:	2
Request:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Response:	no response

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

The CALLBACK_COUNT callback is only triggered if the count has changed since the last triggering.

BrickletRotaryEncoder.get_count_callback_period¶

Function ID:	3
Request:	empty payload
Response:	period – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0

Returns the period as set by set_count_callback_period.

BrickletRotaryEncoder.set_count_callback_threshold¶

Function ID:	4
Request:	option – Type: char, Range: See meanings, Default: 'x' min – Type: int32, Range: [-2³¹ to 2³¹ - 1], Default: 0 max – Type: int32, Range: [-2³¹ to 2³¹ - 1], Default: 0
Response:	no response

Sets the thresholds for the CALLBACK_COUNT_REACHED callback.

The following options are possible:

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

BrickletRotaryEncoder.get_count_callback_threshold¶

Function ID:	5
Request:	empty payload
Response:	option – Type: char, Range: See meanings, Default: 'x' min – Type: int32, Range: [-2³¹ to 2³¹ - 1], Default: 0 max – Type: int32, Range: [-2³¹ to 2³¹ - 1], Default: 0

Returns the threshold as set by set_count_callback_threshold.

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

For option:

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

BrickletRotaryEncoder.set_debounce_period¶

Function ID:	6
Request:	debounce – Type: uint32, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 100
Response:	no response

Sets the period with which the threshold callback

CALLBACK_COUNT_REACHED

is triggered, if the thresholds

set_count_callback_threshold

keeps being reached.

BrickletRotaryEncoder.get_debounce_period¶

Function ID:	7
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¶

BrickletRotaryEncoder.CALLBACK_COUNT¶

Function ID:	8
Response:	count – Type: int32, Range: [-2³¹ to 2³¹ - 1]

This callback is triggered periodically with the period that is set by set_count_callback_period. The response value is the count of the encoder.

The CALLBACK_COUNT callback is only triggered if the count has changed since the last triggering.

BrickletRotaryEncoder.CALLBACK_COUNT_REACHED¶

Function ID:	9
Response:	count – Type: int32, Range: [-2³¹ to 2³¹ - 1]

This callback is triggered when the threshold as set by set_count_callback_threshold is reached. The response value is the count of the encoder.

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

BrickletRotaryEncoder.CALLBACK_PRESSED¶

Function ID:	11
Response:	empty payload

This callback is triggered when the button is pressed.

BrickletRotaryEncoder.CALLBACK_RELEASED¶

Function ID:	12
Response:	empty payload

This callback is triggered when the button is released.