While not "free," you can buy a used or CompactLogix L16ER for under $300 on eBay and use the free version of RSLogix Micro Starter Lite (for MicroLogix) or the 7-day trial of Studio 5000. This is a one-time cost that many professionals recommend.
It is important to address the legality of the software. RSLogix and Studio 5000 are proprietary, commercial products owned by Rockwell Automation. rslogix emulate 5000 free download
from a local Rockwell distributor to test the full software suite. Key Features & Performance While not "free," you can buy a used