Active Data Bus HubM1 Data Bus module that is used for retrofit jobs where 4 wire Data Bus cabling is star wired back to one location. NESS M1 ACTIVE DATA BUS HUB Part Number : 101 206 The M1DBHR is an "active" RS 485 data bus hub designed for jobs where an M1 Control is retrofitting an older panel that has multiple homerun 4 conductor keypad data wires. It splits the main 485 data bus into 4 managed 485 branches. Each branch can have 2 parallel home run cables for a