Bose ControlSpace Safety Instructions & Install Manual page 7

Flexible architecture
The ESP employs a flexible, modular architecture. The
flexible architecture provides two levels of DSP perfor-
mance: up to 32 general purpose control inputs and
outputs, and up to 64 audio channels.
ESP Inside View
(ESP-00 shown with optional DSP daughter card)
Installation should only be performed by trained service personnel.
Modularity and Expansion
Remove the eight screws from the cover of the ESP and
slide off the top to access the expansion card slots.
5
(One GPIO slot is loaded,
one is available for expansion)