Delphi/Lazarus - RS232 Bricklet¶

Loopback¶

Download (ExampleLoopback.pas)

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program ExampleLoopback;

{ For this example connect the RX1 and TX pin to receive the send message }

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

uses
  SysUtils, IPConnection, BrickletRS232;

type
  TExample = class
  private
    ipcon: TIPConnection;
    rs232: TBrickletRS232;
  public
    function StringToCharArray(const message_: string): TArray0To59OfChar;
    function CharArrayToString(const message_: TArray0To59OfChar; const length_: byte): string;
    procedure ReadCB(sender: TBrickletRS232; const message_: TArray0To59OfChar;
                     const length_: byte);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your RS232 Bricklet }

var
  e: TExample;

{ Convert string to char array with length 60, as needed by write }
function TExample.StringToCharArray(const message_: string): TArray0To59OfChar;
var i: longint;
begin
  FillChar(result, 60, 0);
  for i := 1 to Length(message_) do begin
    result[i - 1] := message_[i];
  end;
end;

{ Assume that the message consists of ASCII characters and convert it from
  an array of chars to a string }
function TExample.CharArrayToString(const message_: TArray0To59OfChar; const length_: byte): string;
begin
  SetString(result, PChar(@message_[0]), length_);
end;

{ Callback procedure for read callback }
procedure TExample.ReadCB(sender: TBrickletRS232; const message_: TArray0To59OfChar;
                          const length_: byte);
begin
  WriteLn(Format('Message (Length: %d): "%s"', [length_, CharArrayToString(message_, length_)]));
end;

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

  { Create device object }
  rs232 := TBrickletRS232.Create(UID, ipcon);

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

  { Register read callback to procedure ReadCB }
  rs232.OnRead := {$ifdef FPC}@{$endif}ReadCB;

  { Enable read callback }
  rs232.EnableReadCallback;

  { Write "test" string }
  rs232.Write(StringToCharArray('test'), 4);

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

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

Basic Functions¶

constructor TBrickletRS232.Create(const uid: string; ipcon: TIPConnection)¶

Parameters:	uid – Type: string ipcon – Type: TIPConnection
Returns:	rs232 – Type: TBrickletRS232

Creates an object with the unique device ID uid:

rs232 := TBrickletRS232.Create('YOUR_DEVICE_UID', ipcon);

This object can then be used after the IP Connection is connected.

function TBrickletRS232.Write(const message: array [0..59] of char; const length: byte): byte¶

Parameters:	message – Type: array [0..59] of char length – Type: byte, Range: [0 to 60]
Returns:	written – Type: byte, Range: [0 to 60]

Writes a string of up to 60 characters to the RS232 interface. The string can be binary data, ASCII or similar is not necessary.

The length of the string has to be given as an additional parameter.

The return value is the number of bytes that could be written.

See SetConfiguration for configuration possibilities regarding baudrate, parity and so on.

procedure TBrickletRS232.Read(out message: array [0..59] of char; out length: byte)¶

Output Parameters:	message – Type: array [0..59] of char length – Type: byte, Range: [0 to 60]

Returns the currently buffered message. The maximum length of message is 60. If the returned length is 0, no new data was available.

Instead of polling with this function, you can also use callbacks. See EnableReadCallback and OnRead callback.

procedure TBrickletRS232.SetConfiguration(const baudrate: byte; const parity: byte; const stopbits: byte; const wordlength: byte; const hardwareFlowcontrol: byte; const softwareFlowcontrol: byte)¶

Parameters:	baudrate – Type: byte, Range: See constants, Default: 11 parity – Type: byte, Range: See constants, Default: 0 stopbits – Type: byte, Range: See constants, Default: 1 wordlength – Type: byte, Range: See constants, Default: 8 hardwareFlowcontrol – Type: byte, Range: See constants, Default: 0 softwareFlowcontrol – Type: byte, Range: See constants, Default: 0

Sets the configuration for the RS232 communication.

Hard-/Software flow control can either be on or off but not both simultaneously on.

The following constants are available for this function:

For baudrate:

• BRICKLET_RS232_BAUDRATE_300 = 0
• BRICKLET_RS232_BAUDRATE_600 = 1
• BRICKLET_RS232_BAUDRATE_1200 = 2
• BRICKLET_RS232_BAUDRATE_2400 = 3
• BRICKLET_RS232_BAUDRATE_4800 = 4
• BRICKLET_RS232_BAUDRATE_9600 = 5
• BRICKLET_RS232_BAUDRATE_14400 = 6
• BRICKLET_RS232_BAUDRATE_19200 = 7
• BRICKLET_RS232_BAUDRATE_28800 = 8
• BRICKLET_RS232_BAUDRATE_38400 = 9
• BRICKLET_RS232_BAUDRATE_57600 = 10
• BRICKLET_RS232_BAUDRATE_115200 = 11
• BRICKLET_RS232_BAUDRATE_230400 = 12

For parity:

• BRICKLET_RS232_PARITY_NONE = 0
• BRICKLET_RS232_PARITY_ODD = 1
• BRICKLET_RS232_PARITY_EVEN = 2
• BRICKLET_RS232_PARITY_FORCED_PARITY_1 = 3
• BRICKLET_RS232_PARITY_FORCED_PARITY_0 = 4

For stopbits:

• BRICKLET_RS232_STOPBITS_1 = 1
• BRICKLET_RS232_STOPBITS_2 = 2

For wordlength:

• BRICKLET_RS232_WORDLENGTH_5 = 5
• BRICKLET_RS232_WORDLENGTH_6 = 6
• BRICKLET_RS232_WORDLENGTH_7 = 7
• BRICKLET_RS232_WORDLENGTH_8 = 8

For hardwareFlowcontrol:

• BRICKLET_RS232_HARDWARE_FLOWCONTROL_OFF = 0
• BRICKLET_RS232_HARDWARE_FLOWCONTROL_ON = 1

For softwareFlowcontrol:

• BRICKLET_RS232_SOFTWARE_FLOWCONTROL_OFF = 0
• BRICKLET_RS232_SOFTWARE_FLOWCONTROL_ON = 1

procedure TBrickletRS232.GetConfiguration(out baudrate: byte; out parity: byte; out stopbits: byte; out wordlength: byte; out hardwareFlowcontrol: byte; out softwareFlowcontrol: byte)¶

Output Parameters:	baudrate – Type: byte, Range: See constants, Default: 11 parity – Type: byte, Range: See constants, Default: 0 stopbits – Type: byte, Range: See constants, Default: 1 wordlength – Type: byte, Range: See constants, Default: 8 hardwareFlowcontrol – Type: byte, Range: See constants, Default: 0 softwareFlowcontrol – Type: byte, Range: See constants, Default: 0

Returns the configuration as set by SetConfiguration.

The following constants are available for this function:

For baudrate:

• BRICKLET_RS232_BAUDRATE_300 = 0
• BRICKLET_RS232_BAUDRATE_600 = 1
• BRICKLET_RS232_BAUDRATE_1200 = 2
• BRICKLET_RS232_BAUDRATE_2400 = 3
• BRICKLET_RS232_BAUDRATE_4800 = 4
• BRICKLET_RS232_BAUDRATE_9600 = 5
• BRICKLET_RS232_BAUDRATE_14400 = 6
• BRICKLET_RS232_BAUDRATE_19200 = 7
• BRICKLET_RS232_BAUDRATE_28800 = 8
• BRICKLET_RS232_BAUDRATE_38400 = 9
• BRICKLET_RS232_BAUDRATE_57600 = 10
• BRICKLET_RS232_BAUDRATE_115200 = 11
• BRICKLET_RS232_BAUDRATE_230400 = 12

For parity:

• BRICKLET_RS232_PARITY_NONE = 0
• BRICKLET_RS232_PARITY_ODD = 1
• BRICKLET_RS232_PARITY_EVEN = 2
• BRICKLET_RS232_PARITY_FORCED_PARITY_1 = 3
• BRICKLET_RS232_PARITY_FORCED_PARITY_0 = 4

For stopbits:

• BRICKLET_RS232_STOPBITS_1 = 1
• BRICKLET_RS232_STOPBITS_2 = 2

For wordlength:

• BRICKLET_RS232_WORDLENGTH_5 = 5
• BRICKLET_RS232_WORDLENGTH_6 = 6
• BRICKLET_RS232_WORDLENGTH_7 = 7
• BRICKLET_RS232_WORDLENGTH_8 = 8

For hardwareFlowcontrol:

• BRICKLET_RS232_HARDWARE_FLOWCONTROL_OFF = 0
• BRICKLET_RS232_HARDWARE_FLOWCONTROL_ON = 1

For softwareFlowcontrol:

• BRICKLET_RS232_SOFTWARE_FLOWCONTROL_OFF = 0
• BRICKLET_RS232_SOFTWARE_FLOWCONTROL_ON = 1

procedure TBrickletRS232.SetBreakCondition(const breakTime: word)¶

Parameters:	breakTime – Type: word, Unit: 1 ms, Range: [0 to 216 - 1]

Sets a break condition (the TX output is forced to a logic 0 state). The parameter sets the hold-time of the break condition.

New in version 2.0.2 (Plugin).

procedure TBrickletRS232.ReadFrame(out message: array [0..59] of char; out length: byte)¶

Output Parameters:	message – Type: array [0..59] of char length – Type: byte, Range: [0 to 60]

Returns up to one frame of bytes from the read buffer. The frame size is configured with SetFrameReadableCallbackConfiguration. If the returned length is 0, no new data was available.

New in version 2.0.4 (Plugin).

Advanced Functions¶

procedure TBrickletRS232.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)¶

Output Parameters:

uid – Type: string, Length: up to 8 connectedUid – Type: string, Length: up to 8 position – Type: char, Range: ['a' to 'h', 'z'] hardwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] firmwareVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255] deviceIdentifier – Type: word, 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. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

procedure TBrickletRS232.EnableReadCallback¶

Enables the OnRead callback. This will disable the OnFrameReadable callback.

By default the callback is disabled.

procedure TBrickletRS232.DisableReadCallback¶

Disables the OnRead callback.

By default the callback is disabled.

function TBrickletRS232.IsReadCallbackEnabled: boolean¶

Returns:	enabled – Type: boolean, Default: false

Returns true if the OnRead callback is enabled, false otherwise.

procedure TBrickletRS232.SetFrameReadableCallbackConfiguration(const frameSize: byte)¶

Parameters:	frameSize – Type: byte, Unit: 1 B, Range: [0 to 100], Default: 0

Configures the OnFrameReadable callback. The frame size is the number of bytes, that have to be readable to trigger the callback. A frame size of 0 disables the callback. A frame size greater than 0 enables the callback and disables the OnRead callback.

By default the callback is disabled.

New in version 2.0.4 (Plugin).

function TBrickletRS232.GetFrameReadableCallbackConfiguration: byte¶

Returns:	frameSize – Type: byte, Unit: 1 B, Range: [0 to 100], Default: 0

Returns the callback configuration as set by SetFrameReadableCallbackConfiguration.

New in version 2.0.4 (Plugin).

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: TBrickletRS232; const value: longint);
begin
  WriteLn(Format('Value: %d', [value]));
end;

rs232.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback properties and their parameter types are described below.

property TBrickletRS232.OnRead¶

procedure(sender: TBrickletRS232; const message: array [0..59] of char; const length: byte) of object;

Callback Parameters:	sender – Type: TBrickletRS232 message – Type: array [0..59] of char length – Type: byte, Range: [1 to 60]

This callback is called if new data is available. The message has a maximum size of 60 characters. The actual length of the message is given in addition.

To enable this callback, use EnableReadCallback.

property TBrickletRS232.OnError¶

procedure(sender: TBrickletRS232; const error: byte) of object;

Callback Parameters:	sender – Type: TBrickletRS232 error – Type: byte, Range: See constants

This callback is called if an error occurs. Possible errors are overrun, parity or framing error.

The following constants are available for this function:

For error:

• BRICKLET_RS232_ERROR_OVERRUN = 1
• BRICKLET_RS232_ERROR_PARITY = 2
• BRICKLET_RS232_ERROR_FRAMING = 4

New in version 2.0.1 (Plugin).

property TBrickletRS232.OnFrameReadable¶

procedure(sender: TBrickletRS232; const frameCount: byte) of object;

Callback Parameters:	sender – Type: TBrickletRS232 frameCount – Type: byte, Range: [0 to 255]

This callback is called if at least one frame of data is readable. The frame size is configured with SetFrameReadableCallbackConfiguration. The frame count parameter is the number of frames that can be read. This callback is triggered only once until Read or ReadFrame is called. This means, that if you have configured a frame size of X bytes, you can read exactly X bytes using the ReadFrame function, every time the callback triggers without checking the frame count parameter.

New in version 2.0.4 (Plugin).

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

function TBrickletRS232.GetAPIVersion: array [0..2] of byte¶

Output Parameters:	apiVersion – Type: array [0..2] of byte 0: major – Type: byte, Range: [0 to 255] 1: minor – Type: byte, Range: [0 to 255] 2: revision – Type: byte, Range: [0 to 255]

Returns the version of the API definition 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 TBrickletRS232.GetResponseExpected(const functionId: byte): boolean¶

Parameters:	functionId – Type: byte, Range: See constants
Returns:	responseExpected – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BRICKLET_RS232_FUNCTION_ENABLE_READ_CALLBACK = 3
• BRICKLET_RS232_FUNCTION_DISABLE_READ_CALLBACK = 4
• BRICKLET_RS232_FUNCTION_SET_CONFIGURATION = 6
• BRICKLET_RS232_FUNCTION_SET_BREAK_CONDITION = 10
• BRICKLET_RS232_FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 11

procedure TBrickletRS232.SetResponseExpected(const functionId: byte; const responseExpected: boolean)¶

Parameters:	functionId – Type: byte, Range: See constants responseExpected – Type: 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BRICKLET_RS232_FUNCTION_ENABLE_READ_CALLBACK = 3
• BRICKLET_RS232_FUNCTION_DISABLE_READ_CALLBACK = 4
• BRICKLET_RS232_FUNCTION_SET_CONFIGURATION = 6
• BRICKLET_RS232_FUNCTION_SET_BREAK_CONDITION = 10
• BRICKLET_RS232_FUNCTION_SET_FRAME_READABLE_CALLBACK_CONFIGURATION = 11

procedure TBrickletRS232.SetResponseExpectedAll(const responseExpected: boolean)¶

Parameters:	responseExpected – Type: boolean

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

Constants¶

const BRICKLET_RS232_DEVICE_IDENTIFIER¶

This constant is used to identify a RS232 Bricklet.

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

const BRICKLET_RS232_DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a RS232 Bricklet.