Purpose

To create a python API for working with National Instruments NIDAQmx. Check the documentation for details.

Project Maturity

The project is somewhat immature, but works well for where items are implemented. Currently, it has been tested on a single model device; however there is no reason to suspect that the project wouldn't work on any device that supports digital IO, analog inputs, and analog outputs. There is approximately ~80% test coverage and a pretty good start on the documentation.

Installation

python -m pip install daqmx

Usage

You must first import the package:

from ni import NIDAQmxInstrument

You can then allocate the hardware without any further specifiers. Note that, if there is more than one DAQmx instrument available on your PC, the hardware allocated may not be the one you are expecting! Be sure to specify the device name, model number, or serial number to make the hardware acquisition process more deterministic.

daq = NIDAQmxInstrument()  # hardware with no specifiers

daq = NIDAQmxInstrument(device_name='Dev3')  # hardware specified by the device name

daq = NIDAQmxInstrument(model_number='USB-6001')  # hardware specified by model number

daq = NIDAQmxInstrument(serial_number=1234)  # hardware specified by serial number

Once you have the NIDAQmxInstrument instance, then you can use it to operate the instrument. See the examples directory for complete examples.
Some snippets to demonstrate common usages:

daq = NIDAQmxInstrument()  # automatic acquisition of hardware

daq.ao0 = 2.7V  # set the analog out 0 to 2.7V
daq.ao1 = 1.3V  # set the analog out 1 to 1.3V

print(f'daq.ai0.value: {daq.ai0.value:.3f}V')  # print a single sample 
                                               # from analog input 0

values = daq.ai1.capture(
    sample_count=10, rate=100,
    max_voltage=10.0, min_voltage=-10.0,
    mode='differential', timeout=3.0
)  # capture 10 samples from ai1 at a rate of 100Hz in differential mode
print(values)

daq.port0.line2 = True  # set the daq.<port>.<line> to True or False to write
print(daq.port0.line3)  # read the daq.<port>.<line> to read state of line

Contribution Guidelines

Since I don't have access to unlimited instruments, I have to trust that contributions that say they work do actually work. As a result, any new instruments that are contributed should have the following:

• An issue associated with the instrument
• A test in the test directory which describes the necessary connections and implements testing

Pull requests are welcome!