Perl - Industrial Dual 0-20mA Bricklet – Tinkerforge

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# Perl - Industrial Dual 0-20mA Bricklet

This is the description of the Perl 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 Perl API bindings is part of their general description.

## Examples

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

### Simple

Download (example_simple.pl)

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    #!/usr/bin/perl

    use Tinkerforge::IPConnection;
    use Tinkerforge::BrickletIndustrialDual020mA;

    use constant HOST => 'localhost';
    use constant PORT => 4223;
    use constant UID => 'ftn'; # Change to your UID

    my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
    my $dual020 = Tinkerforge::BrickletIndustrialDual020mA->new(&UID, $ipcon); # Create device object

    $ipcon->connect(&HOST, &PORT); # Connect to brickd
    # Don't use device before ipcon is connected

    # Get current current for sensor 1 (unit is nA)
    my $current = $dual020->get_current(1)/(1000.0*1000.0);
    print "Current: $current mA\n";

    print "Press any key to exit...\n";
    <STDIN>;
    $ipcon->disconnect();

### Callback

Download (example_callback.pl)

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    #!/usr/bin/perl

    use Tinkerforge::IPConnection;
    use Tinkerforge::BrickletIndustrialDual020mA;

    use constant HOST => 'localhost';
    use constant PORT => 4223;
    use constant UID => 'ftn'; # Change to your UID

    my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
    my $dual020 = Tinkerforge::BrickletIndustrialDual020mA->new(&UID, $ipcon); # Create device object

    # Callback function for current callback (parameter has unit nA)
    sub cb_current
    {
        my ($sensor, $current) = @_;

        print "Current (sensor $sensor): ".$current/(1000.0*1000.0)." mA\n";
    }

    $ipcon->connect(&HOST, &PORT); # Connect to brickd
    # Don't use device before ipcon is connected

    # Set Period (sensor 1) for current callback to 1s (1000ms)
    # Note: The callback is only called every second if the
    #       current has changed since the last call!
    $dual020->set_current_callback_period(1, 1000);

    # Register current callback to function cb_current
    $dual020->register_callback($dual020->CALLBACK_CURRENT, 'cb_current');

    print "Press any key to exit...\n";
    <STDIN>;
    $ipcon->disconnect();

### Threshold

Download (example_threshold.pl)

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    #!/usr/bin/perl

    use Tinkerforge::IPConnection;
    use Tinkerforge::BrickletIndustrialDual020mA;

    use constant HOST => 'localhost';
    use constant PORT => 4223;
    use constant UID => 'ftn'; # Change to your UID

    my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
    my $dual020 = Tinkerforge::BrickletIndustrialDual020mA->new(&UID, $ipcon); # Create device object

    # Callback for current greater than 10mA
    sub cb_reached
    {
        my ($sensor, $current) = @_;

        print "Current (sensor $sensor) is greather than 10mA: ".$current/(1000.0*1000.0)." mA\n";
    }

    $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)
    $dual020->set_debounce_period(10000);

    # Register threshold reached callback to function cb_reached
    $dual020->register_callback($dual020->CALLBACK_CURRENT_REACHED, 'cb_reached');

    # Configure threshold (sensor 1) for "greater than 10mA" (unit is nA)
    $dual020->set_current_callback_threshold(1, '>', 10*1000*1000, 0);

    print "Press any key to exit...\n";
    <STDIN>;
    $ipcon->disconnect();

## API

Generally, every subroutine of the Perl bindings can report an error as `Tinkerforge::Error` object via `croak()`. The object has a `get_code()` and a `get_message()` subroutine. There are different error code:

- Error->ALREADY_CONNECTED = 11
- Error->NOT_CONNECTED = 12
- Error->CONNECT_FAILED = 13
- Error->INVALID_FUNCTION_ID = 21
- Error->TIMEOUT = 31
- Error->INVALID_PARAMETER = 41
- Error->FUNCTION_NOT_SUPPORTED = 42
- Error->UNKNOWN_ERROR = 43

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

`BrickletIndustrialDual020mA``->``new`($uid, $ipcon)

  Parameters:

  - $uid -- string
  - $ipcon -- IPConnection

  Return type: | BrickletIndustrialDual020mA

  Creates an object with the unique device ID `$uid`:

      $industrial_dual_0_20ma = BrickletIndustrialDual020mA->new("YOUR_DEVICE_UID", $ipcon);

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

`BrickletIndustrialDual020mA``->``get_current`($sensor)

  Parameters: | $sensor -- int
  Return type: | int

  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 `CALLBACK_CURRENT` and set the period with `set_current_callback_period()`.

### Advanced Functions

`BrickletIndustrialDual020mA``->``set_sample_rate`($rate)

  Parameters: | $rate -- int
  Return type: | undef

  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

`BrickletIndustrialDual020mA``->``get_sample_rate`()

  Return type: | int

  Returns the sample rate as set by `set_sample_rate()`.

  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

`BrickletIndustrialDual020mA``->``get_api_version`()

  Return type: | [int, int, int]

  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.

`BrickletIndustrialDual020mA``->``get_response_expected`($function_id)

  Parameters: | $function_id -- int
  Return type: | bool

  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 `set_response_expected()`. 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 `set_response_expected()` for the list of function ID constants available for this function.

`BrickletIndustrialDual020mA``->``set_response_expected`($function_id, $response_expected)

  Parameters:

  - $function_id -- int
  - $response_expected -- bool

  Return type: | undef

  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:

  - 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

`BrickletIndustrialDual020mA``->``set_response_expected_all`($response_expected)

  Parameters: | $response_expected -- bool
  Return type: | undef

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

`BrickletIndustrialDual020mA``->``get_identity`()

  Return type: | [string, string, char, [int, int, int], [int, int, int], int]

  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 array contains the elements `uid`, `connected_uid`, `position`, `hardware_version`, `firmware_version` and `device_identifier`.

### Callback Configuration Functions

`BrickletIndustrialDual020mA``->``register_callback`($id, $callback)

  Parameters:

  - $id -- int
  - $callback -- string

  Return type: | undef

  Registers a callback with ID `$id` to the function named `$callback`. The available IDs with corresponding function signatures are listed below.

`BrickletIndustrialDual020mA``->``set_current_callback_period`($sensor, $period)

  Parameters:

  - $sensor -- int
  - $period -- int

  Return type: | undef

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

  `CALLBACK_CURRENT` is only triggered if the current has changed since the last triggering.

  The default value is 0.

`BrickletIndustrialDual020mA``->``get_current_callback_period`($sensor)

  Parameters: | $sensor -- int
  Return type: | int

  Returns the period as set by `set_current_callback_period()`.

`BrickletIndustrialDual020mA``->``set_current_callback_threshold`($sensor, $option, $min, $max)

  Parameters:

  - $sensor -- int
  - $option -- char
  - $min -- int
  - $max -- int

  Return type: | undef

  Sets the thresholds for the `CALLBACK_CURRENT_REACHED` 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 = '>'

`BrickletIndustrialDual020mA``->``get_current_callback_threshold`($sensor)

  Parameters: | $sensor -- int
  Return type: | [char, int, int]

  Returns the threshold as set by `set_current_callback_threshold()`.

  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 array contains the elements `option`, `min` and `max`.

`BrickletIndustrialDual020mA``->``set_debounce_period`($debounce)

  Parameters: | $debounce -- int
  Return type: | undef

  Sets the period in ms with which the threshold callback

  - `CALLBACK_CURRENT_REACHED`

  is triggered, if the threshold

  - `set_current_callback_threshold()`

  keeps being reached.

  The default value is 100.

`BrickletIndustrialDual020mA``->``get_debounce_period`()

  Return type: | int

  Returns the debounce period as set by `set_debounce_period()`.

### Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the `register_callback()` function of the device object. The first parameter is the callback ID and the second parameter the callback function name:

    sub my_callback
    {
        print "@_[0]";
    }

    $industrial_dual_0_20ma->register_callback(BrickletIndustrialDual020mA->CALLBACK_EXAMPLE, 'my_callback')

The callback function will be called from an internal thread of the IP Connection. In contrast to many other programming languages, variables are not automatically shared between threads in Perl. If you want to share a global variable between a callback function and the rest for your program it has to be marked as `:shared`. See the documentation of the threads::shared Perl module for more details.

The available constants with inherent number and 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.

`BrickletIndustrialDual020mA``->``CALLBACK_CURRENT`

  Parameters:

  - $sensor -- int
  - $current -- int

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

  `CALLBACK_CURRENT` is only triggered if the current has changed since the last triggering.

`BrickletIndustrialDual020mA``->``CALLBACK_CURRENT_REACHED`

  Parameters:

  - $sensor -- int
  - $current -- int

  This callback is triggered when the threshold as set by `set_current_callback_threshold()` 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 `set_debounce_period()`.

### Constants

`BrickletIndustrialDual020mA``->``DEVICE_IDENTIFIER`

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

  The `get_identity()` function and the `CALLBACK_ENUMERATE` callback of the IP Connection have a `device_identifier` parameter to specify the Brick's or Bricklet's type.

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