Modbus - Industrial Dual Analog In Bricklet – Tinkerforge

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# Modbus - Industrial Dual Analog In Bricklet

Note

This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.

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

## API

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

The Bricklet has two input channel. Functions that are related directly to a channel have a `channel` parameter to specify one of the two channels. Valid values for the `channel` parameter are 0 and 1.

### Basic Functions

`BrickletIndustrialDualAnalogIn.``get_voltage`

  Function ID: | 1

  Request:

  - channel -- uint8

  Response:

  - voltage -- int32

  Returns the voltage for the given channel in mV.

  If you want to get the voltage periodically, it is recommended to use the callback `CALLBACK_VOLTAGE` and set the period with `set_voltage_callback_period`.

### Advanced Functions

`BrickletIndustrialDualAnalogIn.``set_sample_rate`

  Function ID: | 8

  Request:

  - rate -- uint8

  Response: | no response

  Sets the sample rate. The sample rate can be between 1 sample per second and 976 samples per second. Decreasing the sample rate will also decrease the noise on the data.

`BrickletIndustrialDualAnalogIn.``get_sample_rate`

  Function ID: | 9
  Request: | empty payload

  Response:

  - rate -- uint8

  Returns the sample rate as set by `set_sample_rate`.

`BrickletIndustrialDualAnalogIn.``set_calibration`

  Function ID: | 10

  Request:

  - offset -- int32[2]
  - gain -- int32[2]

  Response: | no response

  Sets offset and gain of MCP3911 internal calibration registers.

  See MCP3911 datasheet 7.7 and 7.8. The Industrial Dual Analog In Bricklet is already factory calibrated by Tinkerforge. It should not be necessary for you to use this function

`BrickletIndustrialDualAnalogIn.``get_calibration`

  Function ID: | 11
  Request: | empty payload

  Response:

  - offset -- int32[2]
  - gain -- int32[2]

  Returns the calibration as set by `set_calibration`.

`BrickletIndustrialDualAnalogIn.``get_adc_values`

  Function ID: | 12
  Request: | empty payload

  Response:

  - value -- int32[2]

  Returns the ADC values as given by the MCP3911 IC. This function is needed for proper calibration, see `set_calibration`.

`BrickletIndustrialDualAnalogIn.``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

`BrickletIndustrialDualAnalogIn.``set_voltage_callback_period`

  Function ID: | 2

  Request:

  - channel -- uint8
  - period -- uint32

  Response: | no response

  Sets the period in ms with which the `CALLBACK_VOLTAGE` callback is triggered periodically for the given channel. A value of 0 turns the callback off.

  `CALLBACK_VOLTAGE` is only triggered if the voltage has changed since the last triggering.

  The default value is 0.

`BrickletIndustrialDualAnalogIn.``get_voltage_callback_period`

  Function ID: | 3

  Request:

  - channel -- uint8

  Response:

  - period -- uint32

  Returns the period as set by `set_voltage_callback_period`.

`BrickletIndustrialDualAnalogIn.``set_voltage_callback_threshold`

  Function ID: | 4

  Request:

  - channel -- uint8
  - option -- char
  - min -- int32
  - max -- int32

  Response: | no response

  Sets the thresholds for the `CALLBACK_VOLTAGE_REACHED` callback for the given channel.

  The following options are possible:

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

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

`BrickletIndustrialDualAnalogIn.``get_voltage_callback_threshold`

  Function ID: | 5

  Request:

  - channel -- uint8

  Response:

  - option -- char
  - min -- int32
  - max -- int32

  Returns the threshold as set by `set_voltage_callback_threshold`.

`BrickletIndustrialDualAnalogIn.``set_debounce_period`

  Function ID: | 6

  Request:

  - debounce -- uint32

  Response: | no response

  Sets the period in ms with which the threshold callback

  - `CALLBACK_VOLTAGE_REACHED`

  is triggered, if the threshold

  - `set_voltage_callback_threshold`

  keeps being reached.

  The default value is 100.

`BrickletIndustrialDualAnalogIn.``get_debounce_period`

  Function ID: | 7
  Request: | empty payload

  Response:

  - debounce -- uint32

  Returns the debounce period as set by `set_debounce_period`.

### Callbacks

`BrickletIndustrialDualAnalogIn.``CALLBACK_VOLTAGE`

  Function ID: | 13

  Response:

  - channel -- uint8
  - voltage -- int32

  This callback is triggered periodically with the period that is set by `set_voltage_callback_period`. The response value is the voltage of the channel.

  `CALLBACK_VOLTAGE` is only triggered if the voltage has changed since the last triggering.

`BrickletIndustrialDualAnalogIn.``CALLBACK_VOLTAGE_REACHED`

  Function ID: | 14

  Response:

  - channel -- uint8
  - voltage -- int32

  This callback is triggered when the threshold as set by `set_voltage_callback_threshold` is reached. The response value is the voltage of the channel.

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

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