Python - Industrial Digital Out 4 Bricklet

This is the description of the Python API bindings for the Industrial Digital Out 4 Bricklet. General information and technical specifications for the Industrial Digital Out 4 Bricklet are summarized in its hardware description.

An installation guide for the Python API bindings is part of their general description.

Examples

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

Simple

Download (example_simple.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Industrial Digital Out 4 Bricklet

import time

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_industrial_digital_out_4 import BrickletIndustrialDigitalOut4

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    ido4 = BrickletIndustrialDigitalOut4(UID, ipcon) # Create device object

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

    # Set pins alternating high/low 10 times with 100ms delay
    for i in range(10):
        time.sleep(0.1)
        ido4.set_value(1 << 0)
        time.sleep(0.1)
        ido4.set_value(1 << 1)
        time.sleep(0.1)
        ido4.set_value(1 << 2)
        time.sleep(0.1)
        ido4.set_value(1 << 3)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

API

Generally, every method of the Python bindings can throw an tinkerforge.ip_connection.Error exception that has a value and a description property. value can have different values:

  • Error.TIMEOUT = -1
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12

All methods listed below are thread-safe.

Basic Functions

BrickletIndustrialDigitalOut4(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

industrial_digital_out_4 = BrickletIndustrialDigitalOut4("YOUR_DEVICE_UID", ipcon)

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

BrickletIndustrialDigitalOut4.set_value(value_mask)
Parameters:value_mask -- int
Return type:None

Sets the output value with a bitmask (16bit). A 1 in the bitmask means high and a 0 in the bitmask means low.

For example: The value 3 or 0b0011 will turn pins 0-1 high and the other pins low.

If no groups are used (see set_group()), the pins correspond to the markings on the Digital Out 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

BrickletIndustrialDigitalOut4.get_value()
Return type:int

Returns the bitmask as set by set_value().

BrickletIndustrialDigitalOut4.set_selected_values(selection_mask, value_mask)
Parameters:
  • selection_mask -- int
  • value_mask -- int
Return type:

None

Sets the output value with a bitmask, according to the selection mask. The bitmask is 16 bit long, true refers to high and false refers to low.

For example: The values (3, 1) or (0b0011, 0b0001) will turn pin 0 high, pin 1 low the other pins remain untouched.

If no groups are used (see set_group()), the pins correspond to the markings on the Digital Out 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Advanced Functions

BrickletIndustrialDigitalOut4.set_monoflop(selection_mask, value_mask, time)
Parameters:
  • selection_mask -- int
  • value_mask -- int
  • time -- int
Return type:

None

Configures a monoflop of the pins specified by the first parameter bitmask.

The second parameter is a bitmask with the desired value of the specified pins. A 1 in the bitmask means high and a 0 in the bitmask means low.

The third parameter indicates the time (in ms) that the pins should hold the value.

If this function is called with the parameters (9, 1, 1500) or (0b1001, 0b0001, 1500): Pin 0 will get high and pin 3 will get low. In 1.5s pin 0 will get low and pin 3 will get high again.

A monoflop can be used as a fail-safe mechanism. For example: Lets assume you have a RS485 bus and a Digital Out 4 Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds and pin 0 high. Pin 0 will be high all the time. If now the RS485 connection is lost, then pin 0 will turn low in at most two seconds.

BrickletIndustrialDigitalOut4.get_monoflop(pin)
Parameters:pin -- int
Return type:(int, int, int)

Returns (for the given pin) the current value and the time as set by set_monoflop() as well as the remaining time until the value flips.

If the timer is not running currently, the remaining time will be returned as 0.

The returned namedtuple has the variables value, time and time_remaining.

BrickletIndustrialDigitalOut4.set_group(group)
Parameters:group -- [chr, chr, chr, chr]
Return type:None

Sets a group of Digital Out 4 Bricklets that should work together. You can find Bricklets that can be grouped together with get_available_for_group().

The group consists of 4 elements. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Each element can either be one of the ports ('a' to 'd') or 'n' if it should not be used.

For example: If you have two Digital Out 4 Bricklets connected to port A and port B respectively, you could call with ['a', 'b', 'n', 'n'].

Now the pins on the Digital Out 4 on port A are assigned to 0-3 and the pins on the Digital Out 4 on port B are assigned to 4-7. It is now possible to call set_value() and control two Bricklets at the same time.

BrickletIndustrialDigitalOut4.get_group()
Return type:[chr, chr, chr, chr]

Returns the group as set by set_group()

BrickletIndustrialDigitalOut4.get_available_for_group()
Return type:int

Returns a bitmask of ports that are available for grouping. For example the value 5 or 0b0101 means: Port A and port C are connected to Bricklets that can be grouped together.

BrickletIndustrialDigitalOut4.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.

BrickletIndustrialDigitalOut4.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.

BrickletIndustrialDigitalOut4.set_response_expected(function_id, response_expected)
Parameters:
  • function_id -- int
  • response_expected -- bool
Return type:

None

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:

  • BrickletIndustrialDigitalOut4.FUNCTION_SET_VALUE = 1
  • BrickletIndustrialDigitalOut4.FUNCTION_SET_MONOFLOP = 3
  • BrickletIndustrialDigitalOut4.FUNCTION_SET_GROUP = 5
  • BrickletIndustrialDigitalOut4.FUNCTION_SET_SELECTED_VALUES = 9
BrickletIndustrialDigitalOut4.set_response_expected_all(response_expected)
Parameters:response_expected -- bool
Return type:None

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

BrickletIndustrialDigitalOut4.get_identity()
Return type:(str, str, chr, [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 namedtuple has the variables uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletIndustrialDigitalOut4.register_callback(callback_id, function)
Parameters:
  • callback_id -- int
  • function -- callable
Return type:

None

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

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:

def my_callback(param):
    print(param)

industrial_digital_out_4.register_callback(BrickletIndustrialDigitalOut4.CALLBACK_EXAMPLE, my_callback)

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.

BrickletIndustrialDigitalOut4.CALLBACK_MONOFLOP_DONE
Parameters:
  • selection_mask -- int
  • value_mask -- int

This callback is triggered whenever a monoflop timer reaches 0. The parameters contain the involved pins and the current value of the pins (the value after the monoflop).

Constants

BrickletIndustrialDigitalOut4.DEVICE_IDENTIFIER

This constant is used to identify a Industrial Digital Out 4 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.

BrickletIndustrialDigitalOut4.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Industrial Digital Out 4 Bricklet.