1.Hardware Configuration & Device Layout
2.PLC Tag Database & I/O Mapping
3.PLC Program Architecture & Block Structure
4.System Permissive Logic
5.Auto / Manual Mode Control Logic
6.Analog Signal Scaling & Engineering Units
7.CRAH Unit Control Logic
8.Cooling Valve Control Logic
9.Alarm Manager – Latching, Acknowledgement & Alarm Output Logic
10.Failover and Automatic Standby Logic
11. HMI Interface and Data Mapping
12. Supply Air Temperature PID Control
13. PID Temperature Control for CRAH Units
14. VFD Control for CRAH Supply Fan
15. Cooling Valve Control
16. Alarm Manager – Enable, Latching & Severity Logic
17. PID Temperature Control for CRAH Units
18. HMI Interface and Data Exchange
19. CRAH Computer Room Air Handler Control
20. PID Temperature Control and Analog Output Scaling
21. Lead/Lag Fan Capacity Control
22. Lead/Lag Fan Rotation and Sequencing
23. Failover Control and Backup Activation
24. Alarm Management and Latching Logic
25. Fire Alarm Shutdown Logic
26.Differential Pressure Control and Monitoring
27. Humidity Control and Monitoring
28. Runtime Equalization and Rotation Logic
29. N+1 Redundancy Control Logic
30. PROFINET Communication Diagnostics
31. Analog Input Validation and Sensor Fault Detection
32. OB1 Main Program Cycle – Sequence of Operations Overview
33. Cyclic 1-Second Tasks
34. Failover Logic
35. HMI Interface and Command Handling
