Good morning Nghia,

If you're using MicroLogix, I'd suggest upgrading to my PLC Basics Second Extended Edition:

https://theautomationschool.com/courses/plc-basics-ese/

If you're using CompactLogix I would suggest picking up my Compact Basics course in Early Access:

https://theautomationschool.com/courses/compact-basics-course/

Or if you're using ControlLogix I'd suggest one of my PAC Basics courses:

https://theautomationschool.com/courses/pac-basics/

Sincerely,

Shawn Tierney,
Instructor, The Automation School