What are the main differences between the NFS-320 and the NFS2-640?

The primary differences between the NFS-320 and NFS2-640 are loop capacity and physical assembly. The NFS2-640 is a modular system that supports one SLC loop expandable to two (636 total points) using an LEM-320 module (Page 1, 4) [1].

The NFS-320 is a fixed single-loop system supporting 318 points and ships factory-assembled in its cabinet (Page 5, 6) [2].

Both panels utilize the same 3.0 A power supply (6.0 A in alarm) and support 18-200 AH batteries (Page 3) [1], [2].