7790A LAN Interface Unit and Information for the users or site planning.
Information about the 7790A LAN Interface Unit or LIU
How many SCUs can a 7790A support
The 7793 has two channels and if addressed correctly, will handle 32 devices on each channel. This gives the total of 64 SCU units on a single 7793. The 7790A can be address using the HHC to a 7790, 7791, 7792, 7793, 7797. The 7790A replaces the 7797A-C as of January 1, 2013.
The original 7791 was primarily for Access Control.
The original 7792 was primarily for HVAC.
The 7793 is a combination for both and the most popular of the 7790 series.
To clarify, when purchasing a 7790A, you would address as a 7793, then put up to 32 SCUs on each of the channels giving you a total capacity of 64 SCUs.
One alternative is the 7798C which as more memory but only one Channel which means it can handle up to 32 SCU controllers.