You can specify the stacker output tray when multiple stackers are attached.
This mode can be set when the Finisher-AN, the Saddle Finisher-AN, and multiple High Capacity Stacker-H are attached. (See "Finisher-AN/Saddle Finisher-AN/Puncher Unit-BS/Puncher Unit-BT" and "High Capacity Stacker-H.")
Setting the Stacker Output Tray
1.
Press 
(Settings/Registration).
(Settings/Registration).2.
Press [Function Settings] → [Common] → [Paper Output Settings].
3.
Press [Stacker Output Tray Settings].
4.
Select [Output Tray (Stacker a)] or [Output Tray (Stacker b)] → press [OK].