How many Bus Devices for example keypads, input expanders, (M1XIN or wireless receivers), output expanders or serial port expanders do you plan connecting to the M1 Data Bus? The M1 will support two home runs and you can “Daisy Chain” devices using 4-conductor wiring. If you’ve already have more than two home runs using 4-conductor you should use the M1DBHR Data Bus Hub Retro Fit Hub. If you’d like to use Cat 5/6 and home run then use the M1DBH regular Data Bus Hub. Please take a look at page 12 and 13 of the M1 Installation Manual for information on all three methods to wire for the M1 Data Bus Devices