Blackmagicdesign ATEM Installation And Operation Manual page 169

ATEM 1 M/E Broadcast Panel
The ATEM 1 M/E Broadcast Panel is designed for switchers with one mix effects panel,
or if you need a hardware panel to control a mix effects panel on a larger ATEM switcher
with more than one ME.
ATEM 2 M/E Broadcast Panel
This hardware control panel is designed to control two mix effects panels individually.
The panel can control two single ATEM switchers with one mix effects panel, such as
ATEM Television Studio models, or one of the larger ATEM Production Studio or
Broadcast Studio switchers that have 2 mix effects panels.
Using External ATEM Hardware Panels 169