Nice little script!
I do a lot of Python automation and scripting as part of my job, and thought I'd offer some pointers if they're of any use or interest to you.
Config
Separate out your config from the actual program itself. A simple way of doing this is making a config.json file, importing/parsing it and then accessing a config object like `for devices in config`, or you can cheat a bit by making a config.py file with variables, or a single 'config' multi-level dictionary, and import it at the top of the file. You can add this to your .gitignore, and that makes for better practice with config management and keeping a clean repo. It's worth adding the standard Python .gitignore file in to projects as it stops cache files and similar popping up.
Is it still working?
Instead of incrementing a counter, you could record the timestamp/date of the last successful port open check, and display a 'last checked' instead, to make it clearer when there's an issue, and when it occurred. If you wanted to add a feature, you could track the 'last success' date for each port, that way when a port goes down, upon each screen refresh you can display how many seconds since it was last seen like Icinga2 or other monitoring tools.
Sockets
Add a `socket.close()` as you're opening sockets and testing that it was successful, but then not doing anything with them, and not triggering sending the FIN packet to the peer.
Naming
You've got a mix of PascalCase, camelCase, snake_case, and so on (IPAddr, buildCell, iteration_counter...) as well as non-descriptive vars (a, p, c, s). I'd recommend Googling 'PEP 8 Style Guide' as that's the defacto guide that 99% of developers and projects on GitHub and so on will follow. It doesn't cost anything to be descriptive with variables, so try to avoid the single letter names as it can make things complicated at a glance.
If you were interested in using some off the shelf software, Icinga2 is built for this kind of thing, and you can add a TSDB backend for graphing etc. It gives you historical tracking, and the ability to monitor almost all aspects of network devices and systems, great bit of software if you've not heard of it, the docs are worth a read.
Hope none of these came across wrong, let me know if you had any questions!