Sennheiser Evolution Wireless Digital Series Instruction Manual page 134

You have about 20 seconds to do this. The progress bar
shows the remaining time.
The system carries out the firmware update for the trans-
mitter.
The progress of the update is shown on the receiver's display.
The transmitter's display shows that the firmware update is in
progress.
ATTENTION
Canceling the update can impair the function of the transmit-
ter
If the transmitter is turned off during the firmware update, the
update may fail and the transmitter may cease to function cor-
rectly.
Do not turn off the transmitter during the update.
▷
Do not remove the batteries or rechargeable battery pack
▷
during the update.
Make sure that the transmitter's (rechargeable) batteries
▷
are sufficiently charged before updating.
EW-DX EM 2 rack receiver
133