FOCUS Enhancements 3.2 - Manual (Page 183)

Firefly Multi-Zone
™
(MZ)
169
Software Update
The MZ handles software updates in the same manner as the SC.
There is one diffence, however.
Status LED
The MZ Status LED displays RED while an update is occuring
while te SC does not indicate that a update is in progress.
WARNING
Do Not Reboot Firefly SC or MZ during an update.