It looks fun, but...
1.If you build several side by side, should it be one entity?
2.You want text string to control it. It means no way to change the sign except numbers.
3.What if it was built in not rectangular form?


1. That is a good question, to control the whole thing you would need that ...

TL;DR
Buildable modular electronic sign that can display text and circuit network signals.


What ?
Once you build the Electronic Display unit it could look like this:
Factorio_ElectronicDisplay_Unit.jpg

But if you combine many units you can build a bigger display like this:
Factorio ...