MATLAB/Octave - Industrial Dual 0-20mA Bricklet

This is the description of the MATLAB/Octave 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 MATLAB/Octave API bindings is part of their general description.

Examples

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

Simple (MATLAB)

Download (matlab_example_simple.m)

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function matlab_example_simple()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletIndustrialDual020mA;

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

    ipcon = IPConnection(); % Create IP connection
    id020 = handle(BrickletIndustrialDual020mA(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Get current current from sensor 1
    current = id020.getCurrent(1);
    fprintf('Current (Sensor 1): %g mA\n', current/1000000.0);

    input('Press key to exit\n', 's');
    ipcon.disconnect();
end

Callback (MATLAB)

Download (matlab_example_callback.m)

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function matlab_example_callback()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletIndustrialDual020mA;

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

    ipcon = IPConnection(); % Create IP connection
    id020 = handle(BrickletIndustrialDual020mA(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Register current callback to function cb_current
    set(id020, 'CurrentCallback', @(h, e) cb_current(e));

    % Set period for current (sensor 1) callback to 1s (1000ms)
    % Note: The current (sensor 1) callback is only called every second
    %       if the current (sensor 1) has changed since the last call!
    id020.setCurrentCallbackPeriod(1, 1000);

    input('Press key to exit\n', 's');
    ipcon.disconnect();
end

% Callback function for current callback
function cb_current(e)
    fprintf('Sensor: %i\n', e.sensor);
    fprintf('Current: %g mA\n', e.current/1000000.0);
    fprintf('\n');
end

Threshold (MATLAB)

Download (matlab_example_threshold.m)

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function matlab_example_threshold()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletIndustrialDual020mA;

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

    ipcon = IPConnection(); % Create IP connection
    id020 = handle(BrickletIndustrialDual020mA(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    id020.setDebouncePeriod(10000);

    % Register current reached callback to function cb_current_reached
    set(id020, 'CurrentReachedCallback', @(h, e) cb_current_reached(e));

    % Configure threshold for current (sensor 1) "greater than 10 mA"
    id020.setCurrentCallbackThreshold(1, '>', 10*1000000, 0);

    input('Press key to exit\n', 's');
    ipcon.disconnect();
end

% Callback function for current reached callback
function cb_current_reached(e)
    fprintf('Sensor: %i\n', e.sensor);
    fprintf('Current: %g mA\n', e.current/1000000.0);
    fprintf('\n');
end

Simple (Octave)

Download (octave_example_simple.m)

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function octave_example_simple()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    id020 = javaObject("com.tinkerforge.BrickletIndustrialDual020mA", UID, ipcon); % Create device object

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

    % Get current current from sensor 1
    current = id020.getCurrent(1);
    fprintf("Current (Sensor 1): %g mA\n", current/1000000.0);

    input("Press key to exit\n", "s");
    ipcon.disconnect();
end

Callback (Octave)

Download (octave_example_callback.m)

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function octave_example_callback()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    id020 = javaObject("com.tinkerforge.BrickletIndustrialDual020mA", UID, ipcon); % Create device object

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

    % Register current callback to function cb_current
    id020.addCurrentCallback(@cb_current);

    % Set period for current (sensor 1) callback to 1s (1000ms)
    % Note: The current (sensor 1) callback is only called every second
    %       if the current (sensor 1) has changed since the last call!
    id020.setCurrentCallbackPeriod(1, 1000);

    input("Press key to exit\n", "s");
    ipcon.disconnect();
end

% Callback function for current callback
function cb_current(e)
    fprintf("Sensor: %d\n", java2int(e.sensor));
    fprintf("Current: %g mA\n", e.current/1000000.0);
    fprintf("\n");
end

function int = java2int(value)
    if compare_versions(version(), "3.8", "<=")
        int = value.intValue();
    else
        int = value;
    end
end

Threshold (Octave)

Download (octave_example_threshold.m)

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function octave_example_threshold()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    id020 = javaObject("com.tinkerforge.BrickletIndustrialDual020mA", UID, ipcon); % Create device object

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

    % Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    id020.setDebouncePeriod(10000);

    % Register current reached callback to function cb_current_reached
    id020.addCurrentReachedCallback(@cb_current_reached);

    % Configure threshold for current (sensor 1) "greater than 10 mA"
    id020.setCurrentCallbackThreshold(1, ">", 10*1000000, 0);

    input("Press key to exit\n", "s");
    ipcon.disconnect();
end

% Callback function for current reached callback
function cb_current_reached(e)
    fprintf("Sensor: %d\n", java2int(e.sensor));
    fprintf("Current: %g mA\n", e.current/1000000.0);
    fprintf("\n");
end

function int = java2int(value)
    if compare_versions(version(), "3.8", "<=")
        int = value.intValue();
    else
        int = value;
    end
end

API

Generally, every method of the MATLAB bindings that returns a value can throw a TimeoutException. This exception gets thrown if the device did not respond. If a cable based connection is used, it is unlikely that this exception gets thrown (assuming nobody unplugs the device). However, if a wireless connection is used, timeouts will occur if the distance to the device gets too big.

Beside the TimeoutException there is also a NotConnectedException that is thrown if a method needs to communicate with the device while the IP Connection is not connected.

Since the MATLAB bindings are based on Java and Java does not support multiple return values and return by reference is not possible for primitive types, we use small classes that only consist of member variables. The member variables of the returned objects are described in the corresponding method descriptions.

The package for all Brick/Bricklet bindings and the IP Connection is com.tinkerforge.*

All methods 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.

Basic Functions

public class BrickletIndustrialDual020mA(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletIndustrialDual020mA;

industrialDual020mA = BrickletIndustrialDual020mA('YOUR_DEVICE_UID', ipcon);

In Octave:

industrialDual020mA = java_new("com.tinkerforge.BrickletIndustrialDual020mA", "YOUR_DEVICE_UID", ipcon);

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

public int getCurrent(short sensor)

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 CurrentCallback callback and set the period with setCurrentCallbackPeriod().

Advanced Functions

public void setSampleRate(short rate)

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:

  • BrickletIndustrialDual020mA.SAMPLE_RATE_240_SPS = 0
  • BrickletIndustrialDual020mA.SAMPLE_RATE_60_SPS = 1
  • BrickletIndustrialDual020mA.SAMPLE_RATE_15_SPS = 2
  • BrickletIndustrialDual020mA.SAMPLE_RATE_4_SPS = 3
public short getSampleRate()

Returns the sample rate as set by setSampleRate().

The following constants are available for this function:

  • BrickletIndustrialDual020mA.SAMPLE_RATE_240_SPS = 0
  • BrickletIndustrialDual020mA.SAMPLE_RATE_60_SPS = 1
  • BrickletIndustrialDual020mA.SAMPLE_RATE_15_SPS = 2
  • BrickletIndustrialDual020mA.SAMPLE_RATE_4_SPS = 3
public short[] getAPIVersion()

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.

public boolean getResponseExpected(short functionId)

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.

public void setResponseExpected(short functionId, boolean responseExpected)

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:

  • BrickletIndustrialDual020mA.FUNCTION_SET_CURRENT_CALLBACK_PERIOD = 2
  • BrickletIndustrialDual020mA.FUNCTION_SET_CURRENT_CALLBACK_THRESHOLD = 4
  • BrickletIndustrialDual020mA.FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BrickletIndustrialDual020mA.FUNCTION_SET_SAMPLE_RATE = 8
public void setResponseExpectedAll(boolean responseExpected)

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

public BrickletIndustrialDual020mA.Identity getIdentity()

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.

The returned object has the public member variables String uid, String connectedUid, char position, short[] hardwareVersion, short[] firmwareVersion and int deviceIdentifier.

Callback Configuration Functions

public void setCurrentCallbackPeriod(short sensor, long period)

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

The CurrentCallback callback is only triggered if the current has changed since the last triggering.

The default value is 0.

public long getCurrentCallbackPeriod(short sensor)

Returns the period as set by setCurrentCallbackPeriod().

public void setCurrentCallbackThreshold(short sensor, char option, int min, int max)

Sets the thresholds for the CurrentReachedCallback 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:

  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_OFF = 'x'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_GREATER = '>'
public BrickletIndustrialDual020mA.CurrentCallbackThreshold getCurrentCallbackThreshold(short sensor)

Returns the threshold as set by setCurrentCallbackThreshold().

The following constants are available for this function:

  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_OFF = 'x'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_SMALLER = '<'
  • BrickletIndustrialDual020mA.THRESHOLD_OPTION_GREATER = '>'

The returned object has the public member variables char option, int min and int max.

public void setDebouncePeriod(long debounce)

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

public long getDebouncePeriod()

Returns the debounce period as set by setDebouncePeriod().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with "set" function of MATLAB. The parameters consist of the IP Connection object, the callback name and the callback function. For example, it looks like this in MATLAB:

function my_callback(e)
    fprintf('Parameter: %s\n', e.param);
end

set(device, 'ExampleCallback', @(h, e) my_callback(e));

Due to a difference in the Octave Java support the "set" function cannot be used in Octave. The registration is done with "add*Callback" functions of the device object. It looks like this in Octave:

function my_callback(e)
    fprintf("Parameter: %s\n", e.param);
end

device.addExampleCallback(@my_callback);

It is possible to add several callbacks and to remove them with the corresponding "remove*Callback" function.

The parameters of the callback are passed to the callback function as fields of the structure e, which is derived from the java.util.EventObject class. The available callback names with corresponding structure fields 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.

public callback BrickletIndustrialDual020mA.CurrentCallback
Parameters:
  • sensor -- short
  • current -- int

This callback is triggered periodically with the period that is set by setCurrentCallbackPeriod(). The parameter is the current of the sensor.

The CurrentCallback callback is only triggered if the current has changed since the last triggering.

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addCurrentCallback() function. An added callback function can be removed with the removeCurrentCallback() function.

public callback BrickletIndustrialDual020mA.CurrentReachedCallback
Parameters:
  • sensor -- short
  • current -- int

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().

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addCurrentReachedCallback() function. An added callback function can be removed with the removeCurrentReachedCallback() function.

Constants

public static final int BrickletIndustrialDual020mA.DEVICE_IDENTIFIER

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

The getIdentity() function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

public static final String BrickletIndustrialDual020mA.DEVICE_DISPLAY_NAME

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