ASPEN is self organizing. You won't do anything. Once your rack is built and the units interconnected with the single Cat6E cable, the ASPEN units will organize themselves into the correct Master/Slave configuration automatically. The top unit will become the master and all the subsequent units will be slaves. If you add another unit to the stack, it will be added automatically in about 90 seconds. Because the 48 mix buses are bidirectional, whatever assignment you have made for the output mixes will remain correct regardless of position n the rack.

The only effect the sequence will have in your rack will be on the control side. You can control an entire multi-unit ASPEN system through a single RS232 port but it MUST be the RS232 on the Master unit. Commands to the slaves will be preceded with a numerical designator surrounded by square brackets so the stack of ASPEN units will know which command is for which unit. Example : [2]run(3) will run macro number 3 in the second unit in the rack. So, the position of the unit will be important when writing control code.