Those links do a good job breaking down costs when using a cell modem to monitor a PLC from an HMI, but not so much the data used by the programming software.
I have access to some Schneider PLCs so I used Netlimiter 4 to do some active tests and see the data I used and discovered the following (If anyone could do this same kind of test using a Rockwell PLC and RSLogix 5000, I'd be very thankful):
1)When doing a slightly exaggerated number of compiles, 25 MB an hour is a fairly reasonable estimation of data use.
2) The more data shown on the screen (i.e. if you're zoomed out) the more data Unity will use (showing a reasonable amount of data resulted in ~3.04 KB/s UP from the PLC and 709 B/S DOWN to the PLC, whereas showing an entire FBD section with lots of data was practically 7 KB/s UP from the PLC!)
3)Sections sitting in the background consume Data!
4)Closing unused screens and turning off
5) Animation Tables used less data than the same amount of objects being viewed within a section. (1.6 KB/s in the actual section and 970 B/s in the animation table.
So if I left the animations off as much as possible, kept only 1 section open at a time, and grouped my compiles together when possible I could shave a good deal off the 25 MB/hr, but who's actually going to do that?