The Moneris Mobile 8200 handheld terminal does not have an ON/OFF switch.
To power up (or turn on) the terminal when the terminal is not on a base:
if the battery is charged, simply press OK.
OR
place the terminal on a powered base (communications or charge-only).
The green backlight comes on, the READY screen appears and the icon appears until the terminal establishes the charge level of the battery.