nidaqmx-python | A Python API for interacting with NI-DAQmx | REST library

I have seen other questions on the topic on this forum, but none have helped me understand how to deal with this. Most of them also seem to me to be about quite intricated and long code. I believe I am doing something rather simple / would like to do something rather simple. I hope someone can help! Here below extensive explanations and then my current code.

NOTE: please do not delete this question. I have given the following a lot of thought and I have carefully gone through related threads, but to no avail. I also believe it makes sense to post this because it is partly related to a more generic question: that of how to plot in real-time while having callbacks running in the background (see summary at the end), which could be summarized to be my general goal.

Setup and goal: National Instruments acquisition module (this matters litlle) NI cDAQ9178, interfaced via nidaqmx-python, a package maintained by NI with documentation here. Some analog signal is inputed in there, and the goal is to acquire it continuously (until I decide to stop the acquisition) at a certain sampling rate (approximately 1000 Hz) while plotting the signal in real time. The plotting needs not be refreshed nearly so often (10Hz refresh rate would even be fine). I'm using Windows 10 with Python 3.7 in a conda virtual environment, and editing is done in PyCharm. Ideally things should work both in PyCharm and any terminal.

Situation: nidaqmx-python provides high-level functions that allow one to register callbacks (which one defines as one wishes), which are called everytime a certain number of samples (in my case 100, but that's not strict) fills the PC buffer. The idea is that the callback, defined below, reads the buffer at that point, and does something (in my case some low-pass filtering, which I have taken out for conciseness, some storing into a global variable data, and maybe plotting - see below).

Problem: I have been fooling around with having whatever plots the data in real time be included in the callback, but with matplotlib that is a nightmare because the callback uses threads other than the main one, and matplotlib does not like to be called from anywhere outside the main thread. I've googled the heck out of other libraries optimized for real-time plotting (and, I was thinking, hopefully thread safe) but it's not so easy: I cannot get vispy to work and I cannot get pyqtgraph to even install, just to give you some examples. Then I saw several posts on the internet of people actually managing pretty decent real-time animations with matplotlib, despite it having been developped with publication in mind and not these applications; so I thought let's give it a go.

My take: Since I could not have matplotlib do the work from inside the callback, I did the following (which is the code you see below): after the callback and after the task is started with task.start() (that's specific to nidaqmx-python), I just create a while loop which plots the global variable buffer. I thought it was a nice trick: see, buffer is updated (call it that) by the callback every 0.1 seconds or so (does not matter) and, on the side, the while loop is plotting the buffer variable over and over, erasing everytime before plotting, effectively yielding a real-time like plot.

NOTE: I am perfectly aware the plotting part is not nearly as good as it could be made (I probably should use the ax API of matplotlib and the subplots, not to mention animation), but I do not care for the moment. I'll deal with that later and refine it to make it more efficient.

What I want: this actually does what I want ... except, in order to stop it, I introduced the try: and except: statements around the while loop, as you see in the code below. Naturally, pressing CTRL+C does break the loop ... but it then also breaks the whole running script and leaves me with the following error: forrtl: error (200): program aborting due to control-C event, in PyCharm, and the following precision when run from a terminal: