Delphi/Lazarus - Industrial Dual 0-20mA Bricklet 2.0

This is the description of the Delphi/Lazarus API bindings for the Industrial Dual 0-20mA Bricklet 2.0. General information and technical specifications for the Industrial Dual 0-20mA Bricklet 2.0 are summarized in its hardware description.

An installation guide for the Delphi/Lazarus API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (ExampleSimple.pas)

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program ExampleSimple;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletIndustrialDual020mAV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    id020: TBrickletIndustrialDual020mAV2;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet 2.0 }

var
  e: TExample;

procedure TExample.Execute;
var current: longint;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  id020 := TBrickletIndustrialDual020mAV2.Create(UID, ipcon);

  { Connect to brickd }
  ipcon.Connect(HOST, PORT);
  { Don't use device before ipcon is connected }

  { Get current current from channel 0 }
  current := id020.GetCurrent(0);
  WriteLn(Format('Current (Channel 0): %f mA', [current/1000000.0]));

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

Callback

Download (ExampleCallback.pas)

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program ExampleCallback;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletIndustrialDual020mAV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    id020: TBrickletIndustrialDual020mAV2;
  public
    procedure CurrentCB(sender: TBrickletIndustrialDual020mAV2; const channel: byte;
                        const current: longint);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet 2.0 }

var
  e: TExample;

{ Callback procedure for current callback }
procedure TExample.CurrentCB(sender: TBrickletIndustrialDual020mAV2; const channel: byte;
                             const current: longint);
begin
  WriteLn(Format('Channel: %d', [channel]));
  WriteLn(Format('Current: %f mA', [current/1000000.0]));
  WriteLn('');
end;

procedure TExample.Execute;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  id020 := TBrickletIndustrialDual020mAV2.Create(UID, ipcon);

  { Connect to brickd }
  ipcon.Connect(HOST, PORT);
  { Don't use device before ipcon is connected }

  { Register current callback to procedure CurrentCB }
  id020.OnCurrent := {$ifdef FPC}@{$endif}CurrentCB;

  { Set period for current (channel 0) callback to 1s (1000ms) without a threshold }
  id020.SetCurrentCallbackConfiguration(0, 1000, false, 'x', 0, 0);

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

Threshold

Download (ExampleThreshold.pas)

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program ExampleThreshold;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletIndustrialDual020mAV2;

type
  TExample = class
  private
    ipcon: TIPConnection;
    id020: TBrickletIndustrialDual020mAV2;
  public
    procedure CurrentCB(sender: TBrickletIndustrialDual020mAV2; const channel: byte;
                        const current: longint);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet 2.0 }

var
  e: TExample;

{ Callback procedure for current callback }
procedure TExample.CurrentCB(sender: TBrickletIndustrialDual020mAV2; const channel: byte;
                             const current: longint);
begin
  WriteLn(Format('Channel: %d', [channel]));
  WriteLn(Format('Current: %f mA', [current/1000000.0]));
  WriteLn('');
end;

procedure TExample.Execute;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  id020 := TBrickletIndustrialDual020mAV2.Create(UID, ipcon);

  { Connect to brickd }
  ipcon.Connect(HOST, PORT);
  { Don't use device before ipcon is connected }

  { Register current callback to procedure CurrentCB }
  id020.OnCurrent := {$ifdef FPC}@{$endif}CurrentCB;

  { Configure threshold for current (channel 0) "greater than 10 mA"
    with a debounce period of 10s (10000ms) }
  id020.SetCurrentCallbackConfiguration(0, 10000, false, '>', 10*1000000, 0);

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

API

Since Delphi does not support multiple return values directly, we use the out keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

Basic Functions

constructor TBrickletIndustrialDual020mAV2.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

industrialDual020mAV2 := TBrickletIndustrialDual020mAV2.Create('YOUR_DEVICE_UID', ipcon);

This object can then be used after the IP Connection is connected (see examples above).

function TBrickletIndustrialDual020mAV2.GetCurrent(const channel: byte): longint

Returns the current of the specified channel. The value is in nA and between 0nA and 22505322nA (22.5mA).

It is possible to detect if an IEC 60381-1 compatible sensor is connected and if it works probably.

If the returned current is below 4mA, there is likely no sensor connected or the connected sensor is defective. If the returned current is over 20mA, there might be a short circuit or the sensor is defective.

If you want to get the value periodically, it is recommended to use the OnCurrent callback. You can set the callback configuration with SetCurrentCallbackConfiguration.

procedure TBrickletIndustrialDual020mAV2.SetChannelLEDConfig(const channel: byte; const config: byte)

Each channel has a corresponding LED. You can turn the LED off, on or show a heartbeat. You can also set the LED to "Channel Status". In this mode the LED can either be turned on with a pre-defined threshold or the intensity of the LED can change with the measured value.

You can configure the channel status behavior with SetChannelLEDStatusConfig.

By default all channel LEDs are configured as "Channel Status".

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_OFF = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_ON = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_SHOW_CHANNEL_STATUS = 3
function TBrickletIndustrialDual020mAV2.GetChannelLEDConfig(const channel: byte): byte

Returns the channel LED configuration as set by SetChannelLEDConfig

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_OFF = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_ON = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_CONFIG_SHOW_CHANNEL_STATUS = 3
procedure TBrickletIndustrialDual020mAV2.SetChannelLEDStatusConfig(const channel: byte; const min: longint; const max: longint; const config: byte)

Sets the channel LED status config. This config is used if the channel LED is configured as "Channel Status", see SetChannelLEDConfig.

For each channel you can choose between threshold and intensity mode.

In threshold mode you can define a positive or a negative threshold. For a positive threshold set the "min" parameter to the threshold value in nA above which the LED should turn on and set the "max" parameter to 0. Example: If you set a positive threshold of 10mA, the LED will turn on as soon as the current exceeds 10mA and turn off again if it goes below 10mA. For a negative threshold set the "max" parameter to the threshold value in nA below which the LED should turn on and set the "min" parameter to 0. Example: If you set a negative threshold of 10mA, the LED will turn on as soon as the current goes below 10mA and the LED will turn off when the current exceeds 10mA.

In intensity mode you can define a range in nA that is used to scale the brightness of the LED. Example with min=4mA and max=20mA: The LED is off at 4mA and below, on at 20mA and above and the brightness is linearly scaled between the values 4mA and 20mA. If the min value is greater than the max value, the LED brightness is scaled the other way around.

By default the channel LED status config is set to intensity with min=4mA and max=20mA.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_STATUS_CONFIG_THRESHOLD = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_STATUS_CONFIG_INTENSITY = 1
procedure TBrickletIndustrialDual020mAV2.GetChannelLEDStatusConfig(const channel: byte; out min: longint; out max: longint; out config: byte)

Returns the channel LED status configuration as set by SetChannelLEDStatusConfig.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_STATUS_CONFIG_THRESHOLD = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_CHANNEL_LED_STATUS_CONFIG_INTENSITY = 1

Advanced Functions

procedure TBrickletIndustrialDual020mAV2.SetSampleRate(const rate: byte)

Sets the sample rate to either 240, 60, 15 or 4 samples per second. The resolution for the rates is 12, 14, 16 and 18 bit respectively.

Value Description
0 240 samples per second, 12 bit resolution
1 60 samples per second, 14 bit resolution
2 15 samples per second, 16 bit resolution
3 4 samples per second, 18 bit resolution

The default value is 3 (4 samples per second with 18 bit resolution).

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_240_SPS = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_60_SPS = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_15_SPS = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_4_SPS = 3
function TBrickletIndustrialDual020mAV2.GetSampleRate: byte

Returns the gain as set by SetSampleRate.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_240_SPS = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_60_SPS = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_15_SPS = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_SAMPLE_RATE_4_SPS = 3
procedure TBrickletIndustrialDual020mAV2.SetGain(const gain: byte)

Sets a gain between 1x and 8x. If you want to measure a very small current, you can increase the gain to get some more resolution.

Example: If you measure 0.5mA with a gain of 8x the return value will be 4mA.

The default gain is 1x.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_1X = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_2X = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_4X = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_8X = 3
function TBrickletIndustrialDual020mAV2.GetGain: byte

Returns the gain as set by SetGain.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_1X = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_2X = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_4X = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_GAIN_8X = 3
function TBrickletIndustrialDual020mAV2.GetAPIVersion: array [0..2] of byte

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

function TBrickletIndustrialDual020mAV2.GetResponseExpected(const functionId: byte): boolean

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by SetResponseExpected. For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See SetResponseExpected for the list of function ID constants available for this function.

procedure TBrickletIndustrialDual020mAV2.SetResponseExpected(const functionId: byte; const responseExpected: boolean)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_CURRENT_CALLBACK_CONFIGURATION = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_SAMPLE_RATE = 5
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_GAIN = 7
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_CHANNEL_LED_CONFIG = 9
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_CHANNEL_LED_STATUS_CONFIG = 11
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_RESET = 243
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_FUNCTION_WRITE_UID = 248
procedure TBrickletIndustrialDual020mAV2.SetResponseExpectedAll(const responseExpected: boolean)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

procedure TBrickletIndustrialDual020mAV2.GetSPITFPErrorCount(out errorCountAckChecksum: longword; out errorCountMessageChecksum: longword; out errorCountFrame: longword; out errorCountOverflow: longword)

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.

function TBrickletIndustrialDual020mAV2.SetBootloaderMode(const mode: byte): byte

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 constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletIndustrialDual020mAV2.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletIndustrialDual020mAV2.SetWriteFirmwarePointer(const pointer: longword)

Sets the firmware pointer for WriteFirmware. 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.

function TBrickletIndustrialDual020mAV2.WriteFirmware(const data: array [0..63] of byte): byte

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

procedure TBrickletIndustrialDual020mAV2.SetStatusLEDConfig(const config: byte)

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 constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletIndustrialDual020mAV2.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletIndustrialDual020mAV2.GetChipTemperature: smallint

Returns the temperature in °C 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.

procedure TBrickletIndustrialDual020mAV2.Reset

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!

procedure TBrickletIndustrialDual020mAV2.WriteUID(const uid: longword)

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.

function TBrickletIndustrialDual020mAV2.ReadUID: longword

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

procedure TBrickletIndustrialDual020mAV2.GetIdentity(out uid: string; out connectedUid: string; out position: char; out hardwareVersion: array [0..2] of byte; out firmwareVersion: array [0..2] of byte; out deviceIdentifier: word)

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. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

procedure TBrickletIndustrialDual020mAV2.SetCurrentCallbackConfiguration(const channel: byte; const period: longword; const valueHasToChange: boolean; const option: char; const min: longint; const max: longint)

The period in ms is the period with which the OnCurrent 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the OnCurrent callback.

The following options are possible:

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

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

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

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_GREATER = '>'
procedure TBrickletIndustrialDual020mAV2.GetCurrentCallbackConfiguration(const channel: byte; out period: longword; out valueHasToChange: boolean; out option: char; out min: longint; out max: longint)

Returns the callback configuration as set by SetCurrentCallbackConfiguration.

The following constants are available for this function:

  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_OFF = 'x'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_OUTSIDE = 'o'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_INSIDE = 'i'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_SMALLER = '<'
  • BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_THRESHOLD_OPTION_GREATER = '>'

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

procedure TExample.MyCallback(sender: TBrickletIndustrialDual020mAV2; const param: word);
begin
  WriteLn(param);
end;

industrialDual020mAV2.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback property and their type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

property TBrickletIndustrialDual020mAV2.OnCurrent
procedure(sender: TBrickletIndustrialDual020mAV2; const channel: byte; const current: longint) of object;

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

The parameter is the same as GetCurrent.

Constants

const BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_DEVICE_IDENTIFIER

This constant is used to identify a Industrial Dual 0-20mA Bricklet 2.0.

The GetIdentity function and the OnEnumerate callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

const BRICKLET_INDUSTRIAL_DUAL_0_20MA_V2_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Industrial Dual 0-20mA Bricklet 2.0.