This is the description of the Delphi/Lazarus API bindings for the Industrial Dual 0-20mA Bricklet. General information and technical specifications for the Industrial Dual 0-20mA Bricklet are summarized in its hardware description.
An installation guide for the Delphi/Lazarus API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 | program ExampleSimple;
{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}
uses
SysUtils, IPConnection, BrickletIndustrialDual020mA;
type
TExample = class
private
ipcon: TIPConnection;
dual020: TBrickletIndustrialDual020mA;
public
procedure Execute;
end;
const
HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; { Change to your UID }
var
e: TExample;
procedure TExample.Execute;
var current: longint;
begin
{ Create IP connection }
ipcon := TIPConnection.Create;
{ Create device object }
dual020 := TBrickletIndustrialDual020mA.Create(UID, ipcon);
{ Connect to brickd }
ipcon.Connect(HOST, PORT);
{ Don't use device before ipcon is connected }
{ Get current current from sensor 1 (unit is nA) }
current := dual020.GetCurrent(1);
WriteLn(Format('Current: %f mA', [current/(1000.0*1000.0)]));
WriteLn('Press key to exit');
ReadLn;
ipcon.Destroy;
end;
begin
e := TExample.Create;
e.Execute;
e.Destroy;
end.
|
Download (ExampleCallback.pas)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | program ExampleCallback;
{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}
uses
SysUtils, IPConnection, BrickletIndustrialDual020mA;
type
TExample = class
private
ipcon: TIPConnection;
dual020: TBrickletIndustrialDual020mA;
public
procedure CurrentCB(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint);
procedure Execute;
end;
const
HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; { Change to your UID }
var
e: TExample;
{ Callback function for current callback (parameter has unit nA) }
procedure TExample.CurrentCB(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint);
begin
WriteLn(Format('Current (sensor %d): %f mA', [sensor, current/(1000.0*1000.0)]));
end;
procedure TExample.Execute;
begin
{ Create IP connection }
ipcon := TIPConnection.Create;
{ Create device object }
dual020 := TBrickletIndustrialDual020mA.Create(UID, ipcon);
{ Connect to brickd }
ipcon.Connect(HOST, PORT);
{ Don't use device before ipcon is connected }
{ Set Period (sensor 1) for current callback to 1s (1000ms)
Note: The current callback is only called every second if the
current has changed since the last call! }
dual020.SetCurrentCallbackPeriod(1, 1000);
{ Register current callback to procedure CurrentCB }
dual020.OnCurrent := {$ifdef FPC}@{$endif}CurrentCB;
WriteLn('Press key to exit');
ReadLn;
ipcon.Destroy;
end;
begin
e := TExample.Create;
e.Execute;
e.Destroy;
end.
|
Download (ExampleThreshold.pas)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | program ExampleThreshold;
{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}
uses
SysUtils, IPConnection, BrickletIndustrialDual020mA;
type
TExample = class
private
ipcon: TIPConnection;
dual020: TBrickletIndustrialDual020mA;
public
procedure ReachedCB(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint);
procedure Execute;
end;
const
HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; { Change to your UID }
var
e: TExample;
{ Callback for current greater than 10mA }
procedure TExample.ReachedCB(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint);
begin
WriteLn(Format('Current (sensor %d) is greater than 10mA: %f', [sensor, current/(1000.0*1000.0)]));
end;
procedure TExample.Execute;
begin
{ Create IP connection }
ipcon := TIPConnection.Create;
{ Create device object }
dual020 := TBrickletIndustrialDual020mA.Create(UID, ipcon);
{ Connect to brickd }
ipcon.Connect(HOST, PORT);
{ Don't use device before ipcon is connected }
{ Get threshold callbacks with a debounce time of 10 seconds (10000ms) }
dual020.SetDebouncePeriod(10000);
{ Register threshold reached callback to procedure ReachedCB }
dual020.OnCurrentReached := {$ifdef FPC}@{$endif}ReachedCB;
{ Configure threshold (sensor 1) for "greater than 10mA" (unit is nA) }
dual020.SetCurrentCallbackThreshold(1, '>', 10*1000*1000, 0);
WriteLn('Press key to exit');
ReadLn;
ipcon.Destroy;
end;
begin
e := TExample.Create;
e.Execute;
e.Destroy;
end.
|
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.
Two sensors can be connected to the Bricklet. Functions that are related directly to a sensor have a sensor parameter to specify one of the two sensors. Valid values for the sensor parameter are 0 and 1.
Creates an object with the unique device ID uid:
industrialDual020mA := TBrickletIndustrialDual020mA.Create('YOUR_DEVICE_UID', ipcon);
This object can then be used after the IP Connection is connected (see examples above).
Returns the current of the specified sensor (0 or 1). 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 sensor may be defect. If the returned current is over 20mA, there might be a short circuit or the sensor may be defect.
If you want to get the current periodically, it is recommended to use the callback OnCurrent and set the period with SetCurrentCallbackPeriod.
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:
Returns the sample rate as set by SetSampleRate.
The following constants are available for this function:
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.
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.
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 and callbacks it is always disabled.
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:
Changes the response expected flag for all setter and callback configuration functions of this device at once.
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.
Sets the period in ms with which the OnCurrent callback is triggered periodically for the given sensor. A value of 0 turns the callback off.
OnCurrent is only triggered if the current has changed since the last triggering.
The default value is 0.
Returns the period as set by SetCurrentCallbackPeriod.
Sets the thresholds for the OnCurrentReached callback for the given sensor.
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 default value is ('x', 0, 0).
The following constants are available for this function:
Returns the threshold as set by SetCurrentCallbackThreshold.
The following constants are available for this function:
Sets the period in ms with which the threshold callback
is triggered, if the threshold
keeps being reached.
The default value is 100.
Returns the debounce period as set by SetDebouncePeriod.
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: TBrickletIndustrialDual020mA; const param: word); begin WriteLn(param); end; industrialDual020mA.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.
procedure(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint) of object;
This callback is triggered periodically with the period that is set by SetCurrentCallbackPeriod. The parameter is the current of the sensor.
OnCurrent is only triggered if the current has changed since the last triggering.
procedure(sender: TBrickletIndustrialDual020mA; const sensor: byte; const current: longint) of object;
This callback is triggered when the threshold as set by SetCurrentCallbackThreshold is reached. The parameter is the current of the sensor.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by SetDebouncePeriod.
This constant is used to identify a Industrial Dual 0-20mA Bricklet.
The GetIdentity function and the OnEnumerate callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.