mcculw

=========== =================================================================================================================================== Info Contains a Python API for interacting with Measurement Computing's Universal Library in Windows. See GitHub_ for the latest source. Author Measurement Computing =========== ===================================================================================================================================

About

The mcculw package contains an API (Application Programming Interface) for interacting with the I/O Library for Measurement Computing Data Acquisition products, Universal Library. This package was created and is supported by MCC. The package is implemented in Python as a wrapper around the Universal Library C API using the ctypes_ Python Library.

Note: The **mcculw** examples included in version 1.0.0 and later are not backward compatible with pre-release
versions of the **mcculw** Python package.  See the `Examples`_ section for more details.

mcculw is supported for Universal Library 6.55 and later. Some functions in the mcculw package may be unavailable with earlier versions of Universal Library. Visit http://www.mccdaq.com/Software-Downloads.aspx to upgrade your version of UL.

mcculw supports only the Windows operating system.

mcculw supports CPython 2.7 and 3.4+.

The mcculw package is available on GitHub_ and PyPI_.

Installation

1. Install Python version 2.7, 3.4, or later from https://www.python.org/downloads/ .

2. Install the latest version of InstaCal from http://www.mccdaq.com/Software-Downloads.aspx .

3. Install the the MCC UL Python API for Windows (mcculw) and any dependencies using pip:

   a. Open the Windows command prompt: press Win+R, type cmd.exe and press Enter. b. Upgrade pip to the latest version by entering the following command::

    pip install --upgrade pip
   

   c. Install the mcculw library by entering the following command::

    pip install mcculw
   

   Note: If you get a message like "pip is not recognized as an internal or external command...", or if you have multiple Python installations, enter the full path to the pip executable, such as C:\Python27\Scripts\pip install --upgrade pip or C:\Python27\Scripts\pip install mcculw. The pip command is in the Scripts subdirectory of your Python install location.

Examples

Download the examples zip file_ from the mcculw GitHub repository.

Unzip the examples to a known location, such as::

C:\Users\Public\Documents\Measurement Computing\DAQ\Python

Refer to the knowledgebase article Importing Python for Windows example programs into an IDE_ for detailed instructions on how to import examples into popular IDEs such as Eclipse and Visual Studio.

Note: The latest examples take advantage of the **mcculw.device_info** subpackage
added in version 1.0.0. Software developed using the props subpackage included in
the examples folder of pre-release versions will continue to work with version 1.0.0
and later of the **mcculw** Python package, but requires the inclusion of the props subdirectory.
See the mcculw GitHub `Releases`_ page for a complete archive of previous releases.

Usage

The following is a basic example of using the Universal Library to perform analog input. Further examples may be found on GitHub_.

.. code-block:: python

from mcculw import ul from mcculw.enums import ULRange from mcculw.ul import ULError

board_num = 0 channel = 0 ai_range = ULRange.BIP5VOLTS

try: # Get a value from the device value = ul.a_in(board_num, channel, ai_range) # Convert the raw value to engineering units eng_units_value = ul.to_eng_units(board_num, ai_range, value)

  # Display the raw value
  print("Raw Value: " + str(value))
  # Display the engineering value
  print("Engineering Value: " + '{:.3f}'.format(eng_units_value))

except ULError as e: # Display the error print("A UL error occurred. Code: " + str(e.errorcode) + " Message: " + e.message)

Support/Feedback

The mcculw package is supported by MCC. For support for mcculw, contact technical support through http://www.mccdaq.com/Support.aspx . Please include version information for Python, Universal Library and the mcculw packages used as well as detailed steps on how to reproduce the problem in your request.

Bugs/Feature Requests

To report a bug or submit a feature request, please use the mcculw GitHub Issues_ page.

Documentation

Documentation is available in the Universal Library Help_.

.. Links: .. _GitHub: https://github.com/mccdaq/mcculw .. _PyPI: https://pypi.python.org/pypi/mcculw .. _ctypes: https://docs.python.org/3/library/ctypes.html .. _Universal Library Help: https://www.mccdaq.com/PDFs/Manuals/Mcculw_WebHelp/ULStart.htm .. _GitHub Issues: https://github.com/mccdaq/mcculw/issues .. _examples zip file: https://github.com/mccdaq/mcculw/raw/master/examples.zip .. _Importing Python for Windows example programs into an IDE: http://kb.mccdaq.com/KnowledgebaseArticle50716.aspx .. _Releases: https://github.com/mccdaq/mcculw/releases