Interlogix TruPortal Quick Start - Manual (Page 5)

System
Controller
RS-485 Bus
Door
Controller
1.2 Connect RS-485 bus between System
Controller and RS-485 based Add-ons
• There are four independent RS-485 buses. You can use any or all of the four
buses. (31 2-door add-ons maximum; 8 I/O add-ons maximum; 24 modules
per bus maximum)
• Using multiple buses limits the failure scope in cases of individual bus outages
• Maximum distance for each bus is 4000 feet (1200 meters)
• Refer to Quick Reference documents and to wiring diagram on panel door
for additional details
Caution: Do not power add-ons from the System Controller via the RS-485 bus.
Only connect A+, B-, and 0V between the System Controller and the add-ons.