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Programming NI DAQmx board in Python: easier than you think!

For my DIY microscope I had a task - generate a train of digital pulses which simulate camera trigger, so that other devices (galvo and laser) are synched. I wanted to do it in Python, so that it seamlessly integrates in my data acquisition and analysis Jupyter notebook.

After some quick search I found a PyDAQmx library which seemed mature and had good examples to begin with.

Installation was smooth: download, unzip, open Anaconda prompt,
python setup.py install

After only 30 min fiddling, I was able to solve my problem in just a few lines of code:

# Simple digital pulse generation with PyDAQmx library and NI DAQmx board
# Requires NI DAQmx drivers, Python 2.7 installed, Windows.
# Tested on NI PCIe-6321 board
# Gist author: Nikita Vladimirov @nvladimus
import PyDAQmx as pd
ctr_ini_delay = 0 # sec
ctr_period = 0.1 # sec
ctr_duty_cycle = 0.01
task = pd.Task()
task.CreateCOPulseChanFreq("Dev1/ctr0", "CamTrigger", pd.DAQmx_Val_Hz, pd.DAQmx_Val_Low, ctr_ini_delay, 1/float(ctr_period), ctr_duty_cycle)
task.CfgImplicitTiming(pd.DAQmx_Val_ContSamps, 1000)
task.StartTask()
# Go and measure the pulses with oscilloscope.
# Output will be at terminal pin "Ctr0 OUT"
# check your NI DAQmx board pinout diagram for terminal location
# It was "PFI 12" on my board NI PCIe-6321.
task.StopTask()
task.ClearTask()
view raw DAQmxPulseGeneration.py hosted with ❤ by GitHub
Holy crap, it just works, out of the box. Oscilloscope shows nice digital pulses every 100 ms, each 1 ms long. The code is much shorter and cleaner than would be in C, C#, or LabView.

PyDAQmx appears to be a full-power wrapper around native NI DAQmx drivers (yes, they need to be installed), so presumably it can do all that can be done in C or even LabView (this statement needs to be tested).

One can use PyDAQmx to control galvos with fast analog output waveforms, as shown by @kyleellefsen in his code.

Many thanks to @clade for writing PyDAQmx! Really made my day..

My system was: Windows 10, Python 2.7 (x32), NI PCIe-6321 board.

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