If you’re on V20 or earlier , stay only if required by legacy hardware. If you’re starting a new project , use Studio 5000 V32–V35 (latest stable). Avoid V21 unless forced by a specific controller.
| Feature / Aspect | | v19 | v20 | | --- | --- | --- | --- | | Release Year | 2007 | 2010 | 2012 | | OS Compatibility | Windows XP, 7 (32‑bit) | Windows 7 (32/64‑bit), limited on 10 | Windows 7, 8, 10 (with patches) | | Controller Support | L1, L2, L6x, L4x, L6x, older CompactLogix | L6x, L7x, older L3x | Full L7x, L3x, older L8x (limited) | | Major Feature | Added Add‑On Instructions (AOIs) | Safety (CIP Safety) maturity, improved UDTs | Last version with legacy 1756‑I/O | | Stability | Very stable (mature) | Moderate (some service packs) | Excellent (final polished version) | | Project Size Limit | 2 MB (small) | 32 MB | 32 MB | | Rockwell Support Status | Retired | Retired | Retired (but widely used) | rslogix 5000 version better
Historically, changing Data Types (UDTs) or adding features to a running PLC required putting the controller in program mode (stopping the machine). If you’re on V20 or earlier , stay