Might be a weird question, but...
I want you to envision a simple user interface (like a simple Visual Basic form on a computer screen.) This form covers roughly 2/3rd of the screen, and contains a couple columns of variables that are communicated from some external device. Maybe 20 variables total.
The variables populate the VB text fields, and then, based on whatever data is in those columns, the User (that would be you), can click a button to either enable or disable that external device.
Now, my question to you is: If you saw a form like that for the very first time, do you think you would need elaborate instruction, or would you get the gist of it pretty much right away?
Note that I am not asking whether you would need help in interpreting the variables (so that you would know what action to take, if any). Just picture the form ONLY.