What are the differences between Unity Pro Medium, Large and XLarge?



Unity Pro Medium supports the Premium and Atrium PLCs. (Medium does not support 'close loop control function libraries'.)
Unity PRo Large supports the Premium, Atrium and Quantum PLCs.
Unity PRo XL supports the Premium, Atrium, Quantum and Quantum Hot Standby PLCs.

For a complete list of all PLCs and functions supported by each package, see the attached document.