mcculw 1.0.0

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:

   1. Open the Windows command prompt: press Win+R, type cmd.exe and press Enter.

   2. Upgrade pip to the latest version by entering the following command:

      pip install --upgrade pip

   3. 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.

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.